moodle/lib/accesslib.php
Martin Dougiamas 03d9401e7d My Moodle MDL-19124 New version of My Moodle, User profiles and Course profiles, all with block support
Thanks very much to Remote Learner Canada, especially Hubert Chathi and Olav Jordan, for their work on the bulk of this code, and also Mike Churchward for supporting them.  I worked on it after that (actually simplified it by removing a feature temporarily: multiple pages) to bring it more to what I was imagining, and to provide a base to build on and get all the navigation perfect.

There's still work to do.  Some blocks don't quite work as expected, and some of the code still needs upgrading to bring it fully into line with 2.0.  We also could use a much better course overview block and better CSS styling of the profile pages.  But it's definitely more usable this it was, I think.
2010-05-04 13:04:35 +00:00

6392 lines
220 KiB
PHP
Executable File

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file contains functions for managing user access
*
* <b>Public API vs internals</b>
*
* General users probably only care about
*
* Context handling
* - get_context_instance()
* - get_context_instance_by_id()
* - get_parent_contexts()
* - get_child_contexts()
*
* Whether the user can do something...
* - has_capability()
* - has_any_capability()
* - has_all_capabilities()
* - require_capability()
* - require_login() (from moodlelib)
*
* What courses has this user access to?
* - get_user_courses_bycap()
*
* What users can do X in this context?
* - get_users_by_capability()
*
* Enrol/unenrol
* - enrol_into_course()
* - role_assign()/role_unassign()
*
*
* Advanced use
* - load_all_capabilities()
* - reload_all_capabilities()
* - has_capability_in_accessdata()
* - is_siteadmin()
* - get_user_access_sitewide()
* - load_subcontext()
* - get_role_access_bycontext()
*
* <b>Name conventions</b>
*
* "ctx" means context
*
* <b>accessdata</b>
*
* Access control data is held in the "accessdata" array
* which - for the logged-in user, will be in $USER->access
*
* For other users can be generated and passed around (but may also be cached
* against userid in $ACCESSLIB_PRIVATE->accessdatabyuser.
*
* $accessdata is a multidimensional array, holding
* role assignments (RAs), role-capabilities-perm sets
* (role defs) and a list of courses we have loaded
* data for.
*
* Things are keyed on "contextpaths" (the path field of
* the context table) for fast walking up/down the tree.
* <code>
* $accessdata[ra][$contextpath]= array($roleid)
* [$contextpath]= array($roleid)
* [$contextpath]= array($roleid)
* </code>
*
* Role definitions are stored like this
* (no cap merge is done - so it's compact)
*
* <code>
* $accessdata[rdef][$contextpath:$roleid][mod/forum:viewpost] = 1
* [mod/forum:editallpost] = -1
* [mod/forum:startdiscussion] = -1000
* </code>
*
* See how has_capability_in_accessdata() walks up/down the tree.
*
* Normally - specially for the logged-in user, we only load
* rdef and ra down to the course level, but not below. This
* keeps accessdata small and compact. Below-the-course ra/rdef
* are loaded as needed. We keep track of which courses we
* have loaded ra/rdef in
* <code>
* $accessdata[loaded] = array($contextpath, $contextpath)
* </code>
*
* <b>Stale accessdata</b>
*
* For the logged-in user, accessdata is long-lived.
*
* On each pageload we load $ACCESSLIB_PRIVATE->dirtycontexts which lists
* context paths affected by changes. Any check at-or-below
* a dirty context will trigger a transparent reload of accessdata.
*
* Changes at the sytem level will force the reload for everyone.
*
* <b>Default role caps</b>
* The default role assignment is not in the DB, so we
* add it manually to accessdata.
*
* This means that functions that work directly off the
* DB need to ensure that the default role caps
* are dealt with appropriately.
*
* @package moodlecore
* @copyright 1999 onwards Martin Dougiamas http://dougiamas.com
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
/** permission definitions */
define('CAP_INHERIT', 0);
/** permission definitions */
define('CAP_ALLOW', 1);
/** permission definitions */
define('CAP_PREVENT', -1);
/** permission definitions */
define('CAP_PROHIBIT', -1000);
/** context definitions */
define('CONTEXT_SYSTEM', 10);
/** context definitions */
define('CONTEXT_USER', 30);
/** context definitions */
define('CONTEXT_COURSECAT', 40);
/** context definitions */
define('CONTEXT_COURSE', 50);
/** context definitions */
define('CONTEXT_MODULE', 70);
/** context definitions */
define('CONTEXT_BLOCK', 80);
/** capability risks - see {@link http://docs.moodle.org/en/Development:Hardening_new_Roles_system} */
define('RISK_MANAGETRUST', 0x0001);
/** capability risks - see {@link http://docs.moodle.org/en/Development:Hardening_new_Roles_system} */
define('RISK_CONFIG', 0x0002);
/** capability risks - see {@link http://docs.moodle.org/en/Development:Hardening_new_Roles_system} */
define('RISK_XSS', 0x0004);
/** capability risks - see {@link http://docs.moodle.org/en/Development:Hardening_new_Roles_system} */
define('RISK_PERSONAL', 0x0008);
/** capability risks - see {@link http://docs.moodle.org/en/Development:Hardening_new_Roles_system} */
define('RISK_SPAM', 0x0010);
/** capability risks - see {@link http://docs.moodle.org/en/Development:Hardening_new_Roles_system} */
define('RISK_DATALOSS', 0x0020);
/** rolename displays - the name as defined in the role definition */
define('ROLENAME_ORIGINAL', 0);
/** rolename displays - the name as defined by a role alias */
define('ROLENAME_ALIAS', 1);
/** rolename displays - Both, like this: Role alias (Original)*/
define('ROLENAME_BOTH', 2);
/** rolename displays - the name as defined in the role definition and the shortname in brackets*/
define('ROLENAME_ORIGINALANDSHORT', 3);
/** rolename displays - the name as defined by a role alias, in raw form suitable for editing*/
define('ROLENAME_ALIAS_RAW', 4);
/** size limit for context cache */
if (!defined('MAX_CONTEXT_CACHE_SIZE')) {
define('MAX_CONTEXT_CACHE_SIZE', 5000);
}
/**
* Although this looks like a global variable, it isn't really.
*
* It is just a private implementation detail to accesslib that MUST NOT be used elsewhere.
* It is used to cache various bits of data between function calls for performance reasons.
* Sadly, a PHP global variale is the only way to impleemnt this, withough rewriting everything
* as methods of a class, instead of functions.
*
* @global stdClass $ACCESSLIB_PRIVATE
* @name $ACCESSLIB_PRIVATE
*/
$ACCESSLIB_PRIVATE = new stdClass;
$ACCESSLIB_PRIVATE->contexts = array(); // Cache of context objects by level and instance
$ACCESSLIB_PRIVATE->contextsbyid = array(); // Cache of context objects by id
$ACCESSLIB_PRIVATE->systemcontext = NULL; // Used in get_system_context
$ACCESSLIB_PRIVATE->dirtycontexts = NULL; // Dirty contexts cache
$ACCESSLIB_PRIVATE->accessdatabyuser = array(); // Holds the $accessdata structure for users other than $USER
$ACCESSLIB_PRIVATE->roledefinitions = array(); // role definitions cache - helps a lot with mem usage in cron
$ACCESSLIB_PRIVATE->croncache = array(); // Used in get_role_access
$ACCESSLIB_PRIVATE->preloadedcourses = array(); // Used in preload_course_contexts.
$ACCESSLIB_PRIVATE->capabilities = NULL; // detailed information about the capabilities
/**
* Clears accesslib's private caches. ONLY BE USED BY UNIT TESTS
*
* This method should ONLY BE USED BY UNIT TESTS. It clears all of
* accesslib's private caches. You need to do this before setting up test data,
* and also at the end fo the tests.
* @global object
* @global object
* @global object
*/
function accesslib_clear_all_caches_for_unit_testing() {
global $UNITTEST, $USER, $ACCESSLIB_PRIVATE;
if (empty($UNITTEST->running)) {
throw new coding_exception('You must not call clear_all_caches outside of unit tests.');
}
$ACCESSLIB_PRIVATE->contexts = array();
$ACCESSLIB_PRIVATE->contextsbyid = array();
$ACCESSLIB_PRIVATE->systemcontext = NULL;
$ACCESSLIB_PRIVATE->dirtycontexts = NULL;
$ACCESSLIB_PRIVATE->accessdatabyuser = array();
$ACCESSLIB_PRIVATE->roledefinitions = array();
$ACCESSLIB_PRIVATE->croncache = array();
$ACCESSLIB_PRIVATE->preloadedcourses = array();
$ACCESSLIB_PRIVATE->capabilities = NULL;
unset($USER->access);
}
/**
* Private function. Add a context object to accesslib's caches.
* @global object
* @param object $context
*/
function cache_context($context) {
global $ACCESSLIB_PRIVATE;
// If there are too many items in the cache already, remove items until
// there is space
while (count($ACCESSLIB_PRIVATE->contextsbyid) >= MAX_CONTEXT_CACHE_SIZE) {
$first = reset($ACCESSLIB_PRIVATE->contextsbyid);
unset($ACCESSLIB_PRIVATE->contextsbyid[$first->id]);
unset($ACCESSLIB_PRIVATE->contexts[$first->contextlevel][$first->instanceid]);
}
$ACCESSLIB_PRIVATE->contexts[$context->contextlevel][$context->instanceid] = $context;
$ACCESSLIB_PRIVATE->contextsbyid[$context->id] = $context;
}
/**
* This is really slow!!! do not use above course context level
*
* @global object
* @param int $roleid
* @param object $context
* @return array
*/
function get_role_context_caps($roleid, $context) {
global $DB;
//this is really slow!!!! - do not use above course context level!
$result = array();
$result[$context->id] = array();
// first emulate the parent context capabilities merging into context
$searchcontexts = array_reverse(get_parent_contexts($context));
array_push($searchcontexts, $context->id);
foreach ($searchcontexts as $cid) {
if ($capabilities = $DB->get_records('role_capabilities', array('roleid'=>$roleid, 'contextid'=>$cid))) {
foreach ($capabilities as $cap) {
if (!array_key_exists($cap->capability, $result[$context->id])) {
$result[$context->id][$cap->capability] = 0;
}
$result[$context->id][$cap->capability] += $cap->permission;
}
}
}
// now go through the contexts bellow given context
$searchcontexts = array_keys(get_child_contexts($context));
foreach ($searchcontexts as $cid) {
if ($capabilities = $DB->get_records('role_capabilities', array('roleid'=>$roleid, 'contextid'=>$cid))) {
foreach ($capabilities as $cap) {
if (!array_key_exists($cap->contextid, $result)) {
$result[$cap->contextid] = array();
}
$result[$cap->contextid][$cap->capability] = $cap->permission;
}
}
}
return $result;
}
/**
* Gets the accessdata for role "sitewide" (system down to course)
*
* @global object
* @global object
* @param int $roleid
* @param array $accessdata defaults to NULL
* @return array
*/
function get_role_access($roleid, $accessdata=NULL) {
global $CFG, $DB;
/* Get it in 1 cheap DB query...
* - relevant role caps at the root and down
* to the course level - but not below
*/
if (is_null($accessdata)) {
$accessdata = array(); // named list
$accessdata['ra'] = array();
$accessdata['rdef'] = array();
$accessdata['loaded'] = array();
}
//
// Overrides for the role IN ANY CONTEXTS
// down to COURSE - not below -
//
$sql = "SELECT ctx.path,
rc.capability, rc.permission
FROM {context} ctx
JOIN {role_capabilities} rc
ON rc.contextid=ctx.id
WHERE rc.roleid = ?
AND ctx.contextlevel <= ".CONTEXT_COURSE."
ORDER BY ctx.depth, ctx.path";
$params = array($roleid);
// we need extra caching in CLI scripts and cron
if (CLI_SCRIPT) {
global $ACCESSLIB_PRIVATE;
if (!isset($ACCESSLIB_PRIVATE->croncache[$roleid])) {
$ACCESSLIB_PRIVATE->croncache[$roleid] = array();
if ($rs = $DB->get_recordset_sql($sql, $params)) {
foreach ($rs as $rd) {
$ACCESSLIB_PRIVATE->croncache[$roleid][] = $rd;
}
$rs->close();
}
}
foreach ($ACCESSLIB_PRIVATE->croncache[$roleid] as $rd) {
$k = "{$rd->path}:{$roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
} else {
if ($rs = $DB->get_recordset_sql($sql, $params)) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
unset($rd);
$rs->close();
}
}
return $accessdata;
}
/**
* Gets the accessdata for role "sitewide" (system down to course)
*
* @global object
* @global object
* @param int $roleid
* @param array $accessdata defaults to NULL
* @return array
*/
function get_default_frontpage_role_access($roleid, $accessdata=NULL) {
global $CFG, $DB;
$frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
$base = '/'. SYSCONTEXTID .'/'. $frontpagecontext->id;
//
// Overrides for the role in any contexts related to the course
//
$sql = "SELECT ctx.path,
rc.capability, rc.permission
FROM {context} ctx
JOIN {role_capabilities} rc
ON rc.contextid=ctx.id
WHERE rc.roleid = ?
AND (ctx.id = ".SYSCONTEXTID." OR ctx.path LIKE ?)
AND ctx.contextlevel <= ".CONTEXT_COURSE."
ORDER BY ctx.depth, ctx.path";
$params = array($roleid, "$base/%");
if ($rs = $DB->get_recordset_sql($sql, $params)) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
unset($rd);
$rs->close();
}
return $accessdata;
}
/**
* Get the default guest role
*
* @global object
* @global object
* @return object role
*/
function get_guest_role() {
global $CFG, $DB;
if (empty($CFG->guestroleid)) {
if ($roles = $DB->get_records('role', array('archetype'=>'guest'))) {
$guestrole = array_shift($roles); // Pick the first one
set_config('guestroleid', $guestrole->id);
return $guestrole;
} else {
debugging('Can not find any guest role!');
return false;
}
} else {
if ($guestrole = $DB->get_record('role', array('id'=>$CFG->guestroleid))) {
return $guestrole;
} else {
//somebody is messing with guest roles, remove incorrect setting and try to find a new one
set_config('guestroleid', '');
return get_guest_role();
}
}
}
/**
* Check whether a user has a paritcular capability in a given context.
*
* For example::
* $context = get_context_instance(CONTEXT_MODULE, $cm->id);
* has_capability('mod/forum:replypost',$context)
*
* By default checks the capabilties of the current user, but you can pass a
* different userid. By default will return true for admin users, but you can override that with the fourth argument.
*
* Guest and not-logged-in users can never get any dangerous capability - that is any write capability
* or capabilities with XSS, config or data loss risks.
*
* @param string $capability the name of the capability to check. For example mod/forum:view
* @param object $context the context to check the capability in. You normally get this with {@link get_context_instance}.
* @param integer|object $user A user id or object. By default (NULL) checks the permissions of the current user.
* @param boolean $doanything If false, ignores effect of admin role assignment
* @return boolean true if the user has this capability. Otherwise false.
*/
function has_capability($capability, $context, $user = NULL, $doanything=true) {
global $USER, $CFG, $DB, $SCRIPT, $ACCESSLIB_PRIVATE;
if (during_initial_install()) {
if ($SCRIPT === "/$CFG->admin/index.php" or $SCRIPT === "/$CFG->admin/cliupgrade.php") {
// we are in an installer - roles can not work yet
return true;
} else {
return false;
}
}
if (strpos($capability, 'moodle/legacy:') === 0) {
throw new coding_exception('Legacy capabilities can not be used any more!');
}
// the original $CONTEXT here was hiding serious errors
// for security reasons do not reuse previous context
if (empty($context)) {
debugging('Incorrect context specified');
return false;
}
if (!is_bool($doanything)) {
throw new coding_exception('Capability parameter "doanything" is wierd ("'.$doanything.'"). This has to be fixed in code.');
}
// make sure there is a real user specified
if ($user === NULL) {
$userid = !empty($USER->id) ? $USER->id : 0;
} else {
$userid = !empty($user->id) ? $user->id : $user;
}
// capability must exist
if (!$capinfo = get_capability_info($capability)) {
debugging('Capability "'.$capability.'" was not found! This should be fixed in code.');
return false;
}
// make sure the guest account and not-logged-in users never get any risky caps no matter what the actual settings are.
if (($capinfo->captype === 'write') or ((int)$capinfo->riskbitmask & (RISK_XSS | RISK_CONFIG | RISK_DATALOSS))) {
if (isguestuser($userid) or $userid == 0) {
return false;
}
}
if (is_null($context->path) or $context->depth == 0) {
//this should not happen
$contexts = array(SYSCONTEXTID, $context->id);
$context->path = '/'.SYSCONTEXTID.'/'.$context->id;
debugging('Context id '.$context->id.' does not have valid path, please use build_context_path()', DEBUG_DEVELOPER);
} else {
$contexts = explode('/', $context->path);
array_shift($contexts);
}
if (CLI_SCRIPT && !isset($USER->access)) {
// In cron, some modules setup a 'fake' $USER,
// ensure we load the appropriate accessdata.
if (isset($ACCESSLIB_PRIVATE->accessdatabyuser[$userid])) {
$ACCESSLIB_PRIVATE->dirtycontexts = NULL; //load fresh dirty contexts
} else {
load_user_accessdata($userid);
$ACCESSLIB_PRIVATE->dirtycontexts = array();
}
$USER->access = $ACCESSLIB_PRIVATE->accessdatabyuser[$userid];
} else if (isset($USER->id) && ($USER->id == $userid) && !isset($USER->access)) {
// caps not loaded yet - better to load them to keep BC with 1.8
// not-logged-in user or $USER object set up manually first time here
load_all_capabilities();
$ACCESSLIB_PRIVATE->accessdatabyuser = array(); // reset the cache for other users too, the dirty contexts are empty now
$ACCESSLIB_PRIVATE->roledefinitions = array();
}
// Load dirty contexts list if needed
if (!isset($ACCESSLIB_PRIVATE->dirtycontexts)) {
if (isset($USER->access['time'])) {
$ACCESSLIB_PRIVATE->dirtycontexts = get_dirty_contexts($USER->access['time']);
}
else {
$ACCESSLIB_PRIVATE->dirtycontexts = array();
}
}
// Careful check for staleness...
if (count($ACCESSLIB_PRIVATE->dirtycontexts) !== 0 and is_contextpath_dirty($contexts, $ACCESSLIB_PRIVATE->dirtycontexts)) {
// reload all capabilities - preserving loginas, roleswitches, etc
// and then cleanup any marks of dirtyness... at least from our short
// term memory! :-)
$ACCESSLIB_PRIVATE->accessdatabyuser = array();
$ACCESSLIB_PRIVATE->roledefinitions = array();
if (CLI_SCRIPT) {
load_user_accessdata($userid);
$USER->access = $ACCESSLIB_PRIVATE->accessdatabyuser[$userid];
$ACCESSLIB_PRIVATE->dirtycontexts = array();
} else {
reload_all_capabilities();
}
}
// Find out if user is admin - it is not possible to override the doanything in any way
// and it is not possible to switch to admin role either.
if ($doanything) {
if (is_siteadmin($userid)) {
return true;
}
}
// divulge how many times we are called
//// error_log("has_capability: id:{$context->id} path:{$context->path} userid:$userid cap:$capability");
if (isset($USER->id) && ($USER->id == $userid)) { // we must accept strings and integers in $userid
//
// For the logged in user, we have $USER->access
// which will have all RAs and caps preloaded for
// course and above contexts.
//
// Contexts below courses && contexts that do not
// hang from courses are loaded into $USER->access
// on demand, and listed in $USER->access[loaded]
//
if ($context->contextlevel <= CONTEXT_COURSE) {
// Course and above are always preloaded
return has_capability_in_accessdata($capability, $context, $USER->access);
}
// Load accessdata for below-the-course contexts
if (!path_inaccessdata($context->path,$USER->access)) {
// error_log("loading access for context {$context->path} for $capability at {$context->contextlevel} {$context->id}");
// $bt = debug_backtrace();
// error_log("bt {$bt[0]['file']} {$bt[0]['line']}");
load_subcontext($USER->id, $context, $USER->access);
}
return has_capability_in_accessdata($capability, $context, $USER->access);
}
if (!isset($ACCESSLIB_PRIVATE->accessdatabyuser[$userid])) {
load_user_accessdata($userid);
}
if ($context->contextlevel <= CONTEXT_COURSE) {
// Course and above are always preloaded
return has_capability_in_accessdata($capability, $context, $ACCESSLIB_PRIVATE->accessdatabyuser[$userid]);
}
// Load accessdata for below-the-course contexts as needed
if (!path_inaccessdata($context->path, $ACCESSLIB_PRIVATE->accessdatabyuser[$userid])) {
// error_log("loading access for context {$context->path} for $capability at {$context->contextlevel} {$context->id}");
// $bt = debug_backtrace();
// error_log("bt {$bt[0]['file']} {$bt[0]['line']}");
load_subcontext($userid, $context, $ACCESSLIB_PRIVATE->accessdatabyuser[$userid]);
}
return has_capability_in_accessdata($capability, $context, $ACCESSLIB_PRIVATE->accessdatabyuser[$userid]);
}
/**
* Check if the user has any one of several capabilities from a list.
*
* This is just a utility method that calls has_capability in a loop. Try to put
* the capabilities that most users are likely to have first in the list for best
* performance.
*
* There are probably tricks that could be done to improve the performance here, for example,
* check the capabilities that are already cached first.
*
* @see has_capability()
* @param array $capabilities an array of capability names.
* @param object $context the context to check the capability in. You normally get this with {@link get_context_instance}.
* @param integer $userid A user id. By default (NULL) checks the permissions of the current user.
* @param boolean $doanything If false, ignore effect of admin role assignment
* @return boolean true if the user has any of these capabilities. Otherwise false.
*/
function has_any_capability($capabilities, $context, $userid=NULL, $doanything=true) {
if (!is_array($capabilities)) {
debugging('Incorrect $capabilities parameter in has_any_capabilities() call - must be an array');
return false;
}
foreach ($capabilities as $capability) {
if (has_capability($capability, $context, $userid, $doanything)) {
return true;
}
}
return false;
}
/**
* Check if the user has all the capabilities in a list.
*
* This is just a utility method that calls has_capability in a loop. Try to put
* the capabilities that fewest users are likely to have first in the list for best
* performance.
*
* There are probably tricks that could be done to improve the performance here, for example,
* check the capabilities that are already cached first.
*
* @see has_capability()
* @param array $capabilities an array of capability names.
* @param object $context the context to check the capability in. You normally get this with {@link get_context_instance}.
* @param integer $userid A user id. By default (NULL) checks the permissions of the current user.
* @param boolean $doanything If false, ignore effect of admin role assignment
* @return boolean true if the user has all of these capabilities. Otherwise false.
*/
function has_all_capabilities($capabilities, $context, $userid=NULL, $doanything=true) {
if (!is_array($capabilities)) {
debugging('Incorrect $capabilities parameter in has_all_capabilities() call - must be an array');
return false;
}
foreach ($capabilities as $capability) {
if (!has_capability($capability, $context, $userid, $doanything)) {
return false;
}
}
return true;
}
/**
* Check if the user is an admin at the site level.
*
* Please note that use of proper capabilities is always encouraged,
* this function is supposed to be used from core or for temporary hacks.
*
* @param int|object $user_or_id user id or user object
* @returns bool true if user is one of the administrators, false otherwise
*/
function is_siteadmin($user_or_id = NULL) {
global $CFG, $USER;
if ($user_or_id === NULL) {
$user_or_id = $USER;
}
if (empty($user_or_id)) {
return false;
}
if (!empty($user_or_id->id)) {
// we support
$userid = $user_or_id->id;
} else {
$userid = $user_or_id;
}
$siteadmins = explode(',', $CFG->siteadmins);
return in_array($userid, $siteadmins);
}
/**
* Returns true if user has at least one role assign
* of 'coursemanager' role (is potentially listed in some course descriptions).
* @param $userid
* @return unknown_type
*/
function has_coursemanager_role($userid) {
global $DB;
if (empty($CFG->coursemanager)) {
return false;
}
$sql = "SELECT 1
FROM {role_assignments}
WHERE userid = :userid AND roleid IN ($CFG->coursemanager)";
return $DB->record_exists($sql, array('userid'=>$userid));
}
/**
* @param string $path
* @return string
*/
function get_course_from_path($path) {
// assume that nothing is more than 1 course deep
if (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
return $matches[1];
}
return false;
}
/**
* @param string $path
* @param array $accessdata
* @return bool
*/
function path_inaccessdata($path, $accessdata) {
if (empty($accessdata['loaded'])) {
return false;
}
// assume that contexts hang from sys or from a course
// this will only work well with stuff that hangs from a course
if (in_array($path, $accessdata['loaded'], true)) {
// error_log("found it!");
return true;
}
$base = '/' . SYSCONTEXTID;
while (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
$path = $matches[1];
if ($path === $base) {
return false;
}
if (in_array($path, $accessdata['loaded'], true)) {
return true;
}
}
return false;
}
/**
* Does the user have a capability to do something?
*
* Walk the accessdata array and return true/false.
* Deals with prohibits, roleswitching, aggregating
* capabilities, etc.
*
* The main feature of here is being FAST and with no
* side effects.
*
* Notes:
*
* Switch Roles exits early
* ------------------------
* cap checks within a switchrole need to exit early
* in our bottom up processing so they don't "see" that
* there are real RAs that can do all sorts of things.
*
* Switch Role merges with default role
* ------------------------------------
* If you are a teacher in course X, you have at least
* teacher-in-X + defaultloggedinuser-sitewide. So in the
* course you'll have techer+defaultloggedinuser.
* We try to mimic that in switchrole.
*
* Permission evaluation
* ---------------------
* Originaly there was an extremely complicated way
* to determine the user access that dealt with
* "locality" or role assignemnts and role overrides.
* Now we simply evaluate access for each roel separately
* and then verify if user has at least one role with allow
* and at the same time no role with prohibit.
*
* @param string $capability
* @param object $context
* @param array $accessdata
* @return bool
*/
function has_capability_in_accessdata($capability, $context, array $accessdata) {
global $CFG;
if (empty($context->id)) {
throw new coding_exception('Invalid context specified');
}
// Build $paths as a list of current + all parent "paths" with order bottom-to-top
$contextids = explode('/', trim($context->path, '/'));
$paths = array($context->path);
while ($contextids) {
array_pop($contextids);
$paths[] = '/' . implode('/', $contextids);
}
unset($contextids);
$roles = array();
$switchedrole = false;
// Find out if role switched
if (!empty($accessdata['rsw'])) {
// From the bottom up...
foreach ($paths as $path) {
if (isset($accessdata['rsw'][$path])) {
// Found a switchrole assignment - check for that role _plus_ the default user role
$roles = array($accessdata['rsw'][$path]=>NULL, $CFG->defaultuserroleid=>NULL);
$switchedrole = true;
break;
}
}
}
if (!$switchedrole) {
// get all users roles in this context and above
foreach ($paths as $path) {
if (isset($accessdata['ra'][$path])) {
foreach ($accessdata['ra'][$path] as $roleid) {
$roles[$roleid] = NULL;
}
}
}
}
// Now find out what access is given to each role, going bottom-->up direction
foreach ($roles as $roleid => $ignored) {
foreach ($paths as $path) {
if (isset($accessdata['rdef']["{$path}:$roleid"][$capability])) {
$perm = (int)$accessdata['rdef']["{$path}:$roleid"][$capability];
if ($perm === CAP_PROHIBIT or is_null($roles[$roleid])) {
$roles[$roleid] = $perm;
}
}
}
}
// any CAP_PROHIBIT found means no permission for the user
if (array_search(CAP_PROHIBIT, $roles) !== false) {
return false;
}
// at least one CAP_ALLOW means the user has a permission
return (array_search(CAP_ALLOW, $roles) !== false);
}
/**
* @param object $context
* @param array $accessdata
* @return array
*/
function aggregate_roles_from_accessdata($context, $accessdata) {
$path = $context->path;
// build $contexts as a list of "paths" of the current
// contexts and parents with the order top-to-bottom
$contexts = array($path);
while (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
$path = $matches[1];
array_unshift($contexts, $path);
}
$cc = count($contexts);
$roles = array();
// From the bottom up...
for ($n=$cc-1;$n>=0;$n--) {
$ctxp = $contexts[$n];
if (isset($accessdata['ra'][$ctxp]) && count($accessdata['ra'][$ctxp])) {
// Found assignments on this leaf
$addroles = $accessdata['ra'][$ctxp];
$roles = array_merge($roles, $addroles);
}
}
return array_unique($roles);
}
/**
* A convenience function that tests has_capability, and displays an error if
* the user does not have that capability.
*
* NOTE before Moodle 2.0, this function attempted to make an appropriate
* require_login call before checking the capability. This is no longer the case.
* You must call require_login (or one of its variants) if you want to check the
* user is logged in, before you call this function.
*
* @see has_capability()
*
* @param string $capability the name of the capability to check. For example mod/forum:view
* @param object $context the context to check the capability in. You normally get this with {@link get_context_instance}.
* @param integer $userid A user id. By default (NULL) checks the permissions of the current user.
* @param bool $doanything If false, ignore effect of admin role assignment
* @param string $errorstring The error string to to user. Defaults to 'nopermissions'.
* @param string $stringfile The language file to load the error string from. Defaults to 'error'.
* @return void terminates with an error if the user does not have the given capability.
*/
function require_capability($capability, $context, $userid = NULL, $doanything = true,
$errormessage = 'nopermissions', $stringfile = '') {
if (!has_capability($capability, $context, $userid, $doanything)) {
throw new required_capability_exception($context, $capability, $errormessage, $stringfile);
}
}
/**
* Get an array of courses where cap requested is available
*
* Get an array of courses (with magic extra bits)
* where the accessdata and in DB enrolments show
* that the cap requested is available.
*
* The main use is for get_my_courses().
*
* Notes
*
* - $fields is an array of fieldnames to ADD
* so name the fields you really need, which will
* be added and uniq'd
*
* - the course records have $c->context which is a fully
* valid context object. Saves you a query per course!
*
* - the course records have $c->categorypath to make
* category lookups cheap
*
* - current implementation is split in -
*
* - if the user has the cap systemwide, stupidly
* grab *every* course for a capcheck. This eats
* a TON of bandwidth, specially on large sites
* with separate DBs...
*
* - otherwise, fetch "likely" courses with a wide net
* that should get us _cheaply_ at least the courses we need, and some
* we won't - we get courses that...
* - are in a category where user has the cap
* - or where use has a role-assignment (any kind)
* - or where the course has an override on for this cap
*
* - walk the courses recordset checking the caps oneach one
* the checks are all in memory and quite fast
* (though we could implement a specialised variant of the
* has_capability_in_accessdata() code to speed it up)
*
* @global object
* @global object
* @param string $capability - name of the capability
* @param array $accessdata - accessdata session array
* @param bool $doanything_ignored - admin roles are completely ignored here
* @param string $sort - sorting fields - prefix each fieldname with "c."
* @param array $fields - additional fields you are interested in...
* @param int $limit - set if you want to limit the number of courses
* @return array $courses - ordered array of course objects - see notes above
*/
function get_user_courses_bycap($userid, $cap, $accessdata, $doanything_ignored, $sort='c.sortorder ASC', $fields=NULL, $limit=0) {
global $CFG, $DB;
// Slim base fields, let callers ask for what they need...
$basefields = array('id', 'sortorder', 'shortname', 'idnumber');
if (!is_null($fields)) {
$fields = array_merge($basefields, $fields);
$fields = array_unique($fields);
} else {
$fields = $basefields;
}
// If any of the fields is '*', leave it alone, discarding the rest
// to avoid ambiguous columns under some silly DBs. See MDL-18746 :-D
if (in_array('*', $fields)) {
$fields = array('*');
}
$coursefields = 'c.' .implode(',c.', $fields);
$sort = trim($sort);
if ($sort !== '') {
$sort = "ORDER BY $sort";
}
$sysctx = get_context_instance(CONTEXT_SYSTEM);
if (has_capability_in_accessdata($cap, $sysctx, $accessdata)) {
//
// Apparently the user has the cap sitewide, so walk *every* course
// (the cap checks are moderately fast, but this moves massive bandwidth w the db)
// Yuck.
//
$sql = "SELECT $coursefields,
ctx.id AS ctxid, ctx.path AS ctxpath,
ctx.depth AS ctxdepth, ctx.contextlevel AS ctxlevel,
cc.path AS categorypath
FROM {course} c
JOIN {course_categories} cc
ON c.category=cc.id
JOIN {context} ctx
ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
$sort ";
$rs = $DB->get_recordset_sql($sql);
} else {
//
// narrow down where we have the caps to a few contexts
// this will be a combination of
// - courses where user has an explicit enrolment
// - courses that have an override (any status) on that capability
// - categories where user has the rights (granted status) on that capability
//
$sql = "SELECT ctx.*
FROM {context} ctx
WHERE ctx.contextlevel=".CONTEXT_COURSECAT."
ORDER BY ctx.depth";
$rs = $DB->get_recordset_sql($sql);
$catpaths = array();
foreach ($rs as $catctx) {
if ($catctx->path != ''
&& has_capability_in_accessdata($cap, $catctx, $accessdata)) {
$catpaths[] = $catctx->path;
}
}
$rs->close();
$catclause = '';
$params = array();
if (count($catpaths)) {
$cc = count($catpaths);
for ($n=0;$n<$cc;$n++) {
$catpaths[$n] = "ctx.path LIKE '{$catpaths[$n]}/%'";
}
$catclause = 'WHERE (' . implode(' OR ', $catpaths) .')';
}
unset($catpaths);
/// UNION 3 queries:
/// - user role assignments in courses
/// - user capability (override - any status) in courses
/// - user right (granted status) in categories (optionally executed)
/// Enclosing the 3-UNION into an inline_view to avoid column names conflict and making the ORDER BY cross-db
/// and to allow selection of TEXT columns in the query (MSSQL and Oracle limitation). MDL-16209
$sql = "
SELECT $coursefields, ctxid, ctxpath, ctxdepth, ctxlevel, ctxinstance, categorypath
FROM (
SELECT c.id,
ctx.id AS ctxid, ctx.path AS ctxpath,
ctx.depth AS ctxdepth, ctx.contextlevel AS ctxlevel, ctx.instanceid AS ctxinstance,
cc.path AS categorypath
FROM {course} c
JOIN {course_categories} cc
ON c.category=cc.id
JOIN {context} ctx
ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
JOIN {role_assignments} ra
ON (ra.contextid=ctx.id AND ra.userid=:userid)
UNION
SELECT c.id,
ctx.id AS ctxid, ctx.path AS ctxpath,
ctx.depth AS ctxdepth, ctx.contextlevel AS ctxlevel, ctx.instanceid AS ctxinstance,
cc.path AS categorypath
FROM {course} c
JOIN {course_categories} cc
ON c.category=cc.id
JOIN {context} ctx
ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
JOIN {role_capabilities} rc
ON (rc.contextid=ctx.id AND (rc.capability=:cap)) ";
if (!empty($catclause)) { /// If we have found the right in categories, add child courses here too
$sql .= "
UNION
SELECT c.id,
ctx.id AS ctxid, ctx.path AS ctxpath,
ctx.depth AS ctxdepth, ctx.contextlevel AS ctxlevel, ctx.instanceid AS ctxinstance,
cc.path AS categorypath
FROM {course} c
JOIN {course_categories} cc
ON c.category=cc.id
JOIN {context} ctx
ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
$catclause";
}
/// Close the inline_view and join with courses table to get requested $coursefields
$sql .= "
) inline_view
INNER JOIN {course} c
ON inline_view.id = c.id";
/// To keep cross-db we need to strip any prefix in the ORDER BY clause for queries using UNION
$sql .= "
" . preg_replace('/[a-z]+\./i', '', $sort); /// Add ORDER BY clause
$params['userid'] = $userid;
$params['cap'] = $cap;
$rs = $DB->get_recordset_sql($sql, $params);
}
/// Confirm rights (granted capability) for each course returned
$courses = array();
$cc = 0; // keep count
if ($rs) {
foreach ($rs as $c) {
// build the context obj
context_instance_preload($c);
$context = get_context_instance(CONTEXT_COURSE, $c->id);
if (has_capability_in_accessdata($cap, $context, $accessdata)) {
if ($limit > 0 && $cc >= $limit) {
break;
}
$courses[] = $c;
$cc++;
}
}
$rs->close();
}
return $courses;
}
/**
* Return a nested array showing role assignments
* all relevant role capabilities for the user at
* site/metacourse/course_category/course levels
*
* We do _not_ delve deeper than courses because the number of
* overrides at the module/block levels is HUGE.
*
* [ra] => [/path/][]=roleid
* [rdef] => [/path/:roleid][capability]=permission
* [loaded] => array('/path', '/path')
*
* @global object
* @global object
* @param $userid integer - the id of the user
*/
function get_user_access_sitewide($userid) {
global $CFG, $DB;
/* Get in 3 cheap DB queries...
* - role assignments
* - relevant role caps
* - above and within this user's RAs
* - below this user's RAs - limited to course level
*/
$accessdata = array(); // named list
$accessdata['ra'] = array();
$accessdata['rdef'] = array();
$accessdata['loaded'] = array();
//
// Role assignments
//
$sql = "SELECT ctx.path, ra.roleid
FROM {role_assignments} ra
JOIN {context} ctx ON ctx.id=ra.contextid
WHERE ra.userid = ? AND ctx.contextlevel <= ".CONTEXT_COURSE;
$params = array($userid);
$rs = $DB->get_recordset_sql($sql, $params);
//
// raparents collects paths & roles we need to walk up
// the parenthood to build the rdef
//
$raparents = array();
if ($rs) {
foreach ($rs as $ra) {
// RAs leafs are arrays to support multi
// role assignments...
if (!isset($accessdata['ra'][$ra->path])) {
$accessdata['ra'][$ra->path] = array();
}
array_push($accessdata['ra'][$ra->path], $ra->roleid);
// Concatenate as string the whole path (all related context)
// for this role. This is damn faster than using array_merge()
// Will unique them later
if (isset($raparents[$ra->roleid])) {
$raparents[$ra->roleid] .= $ra->path;
} else {
$raparents[$ra->roleid] = $ra->path;
}
}
unset($ra);
$rs->close();
}
// Walk up the tree to grab all the roledefs
// of interest to our user...
//
// NOTE: we use a series of IN clauses here - which
// might explode on huge sites with very convoluted nesting of
// categories... - extremely unlikely that the number of categories
// and roletypes is so large that we hit the limits of IN()
$clauses = '';
$cparams = array();
foreach ($raparents as $roleid=>$strcontexts) {
$contexts = implode(',', array_unique(explode('/', trim($strcontexts, '/'))));
if ($contexts ==! '') {
if ($clauses) {
$clauses .= ' OR ';
}
$clauses .= "(roleid=? AND contextid IN ($contexts))";
$cparams[] = $roleid;
}
}
if ($clauses !== '') {
$sql = "SELECT ctx.path, rc.roleid, rc.capability, rc.permission
FROM {role_capabilities} rc
JOIN {context} ctx
ON rc.contextid=ctx.id
WHERE $clauses";
unset($clauses);
$rs = $DB->get_recordset_sql($sql, $cparams);
if ($rs) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$rd->roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
unset($rd);
$rs->close();
}
}
//
// Overrides for the role assignments IN SUBCONTEXTS
// (though we still do _not_ go below the course level.
//
// NOTE that the JOIN w sctx is with 3-way triangulation to
// catch overrides to the applicable role in any subcontext, based
// on the path field of the parent.
//
$sql = "SELECT sctx.path, ra.roleid,
ctx.path AS parentpath,
rco.capability, rco.permission
FROM {role_assignments} ra
JOIN {context} ctx
ON ra.contextid=ctx.id
JOIN {context} sctx
ON (sctx.path LIKE " . $DB->sql_concat('ctx.path',"'/%'"). " )
JOIN {role_capabilities} rco
ON (rco.roleid=ra.roleid AND rco.contextid=sctx.id)
WHERE ra.userid = ?
AND ctx.contextlevel <= ".CONTEXT_COURSECAT."
AND sctx.contextlevel <= ".CONTEXT_COURSE."
ORDER BY sctx.depth, sctx.path, ra.roleid";
$params = array($userid);
$rs = $DB->get_recordset_sql($sql, $params);
if ($rs) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$rd->roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
unset($rd);
$rs->close();
}
return $accessdata;
}
/**
* Add to the access ctrl array the data needed by a user for a given context
*
* @global object
* @global object
* @param integer $userid the id of the user
* @param object $context needs path!
* @param array $accessdata accessdata array
*/
function load_subcontext($userid, $context, &$accessdata) {
global $CFG, $DB;
/* Get the additional RAs and relevant rolecaps
* - role assignments - with role_caps
* - relevant role caps
* - above this user's RAs
* - below this user's RAs - limited to course level
*/
$base = "/" . SYSCONTEXTID;
//
// Replace $context with the target context we will
// load. Normally, this will be a course context, but
// may be a different top-level context.
//
// We have 3 cases
//
// - Course
// - BLOCK/PERSON/USER/COURSE(sitecourse) hanging from SYSTEM
// - BLOCK/MODULE/GROUP hanging from a course
//
// For course contexts, we _already_ have the RAs
// but the cost of re-fetching is minimal so we don't care.
//
if ($context->contextlevel !== CONTEXT_COURSE
&& $context->path !== "$base/{$context->id}") {
// Case BLOCK/MODULE/GROUP hanging from a course
// Assumption: the course _must_ be our parent
// If we ever see stuff nested further this needs to
// change to do 1 query over the exploded path to
// find out which one is the course
$courses = explode('/',get_course_from_path($context->path));
$targetid = array_pop($courses);
$context = get_context_instance_by_id($targetid);
}
//
// Role assignments in the context and below
//
$sql = "SELECT ctx.path, ra.roleid
FROM {role_assignments} ra
JOIN {context} ctx
ON ra.contextid=ctx.id
WHERE ra.userid = ?
AND (ctx.path = ? OR ctx.path LIKE ?)
ORDER BY ctx.depth, ctx.path, ra.roleid";
$params = array($userid, $context->path, $context->path."/%");
$rs = $DB->get_recordset_sql($sql, $params);
//
// Read in the RAs, preventing duplicates
//
if ($rs) {
$localroles = array();
$lastseen = '';
foreach ($rs as $ra) {
if (!isset($accessdata['ra'][$ra->path])) {
$accessdata['ra'][$ra->path] = array();
}
// only add if is not a repeat caused
// by capability join...
// (this check is cheaper than in_array())
if ($lastseen !== $ra->path.':'.$ra->roleid) {
$lastseen = $ra->path.':'.$ra->roleid;
array_push($accessdata['ra'][$ra->path], $ra->roleid);
array_push($localroles, $ra->roleid);
}
}
$rs->close();
}
//
// Walk up and down the tree to grab all the roledefs
// of interest to our user...
//
// NOTES
// - we use IN() but the number of roles is very limited.
//
$courseroles = aggregate_roles_from_accessdata($context, $accessdata);
// Do we have any interesting "local" roles?
$localroles = array_diff($localroles,$courseroles); // only "new" local roles
$wherelocalroles='';
if (count($localroles)) {
// Role defs for local roles in 'higher' contexts...
$contexts = substr($context->path, 1); // kill leading slash
$contexts = str_replace('/', ',', $contexts);
$localroleids = implode(',',$localroles);
$wherelocalroles="OR (rc.roleid IN ({$localroleids})
AND ctx.id IN ($contexts))" ;
}
// We will want overrides for all of them
$whereroles = '';
if ($roleids = implode(',',array_merge($courseroles,$localroles))) {
$whereroles = "rc.roleid IN ($roleids) AND";
}
$sql = "SELECT ctx.path, rc.roleid, rc.capability, rc.permission
FROM {role_capabilities} rc
JOIN {context} ctx
ON rc.contextid=ctx.id
WHERE ($whereroles
(ctx.id=? OR ctx.path LIKE ?))
$wherelocalroles
ORDER BY ctx.depth ASC, ctx.path DESC, rc.roleid ASC ";
$params = array($context->id, $context->path."/%");
$newrdefs = array();
if ($rs = $DB->get_recordset_sql($sql, $params)) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$rd->roleid}";
if (!array_key_exists($k, $newrdefs)) {
$newrdefs[$k] = array();
}
$newrdefs[$k][$rd->capability] = $rd->permission;
}
$rs->close();
} else {
debugging('Bad SQL encountered!');
}
compact_rdefs($newrdefs);
foreach ($newrdefs as $key=>$value) {
$accessdata['rdef'][$key] =& $newrdefs[$key];
}
// error_log("loaded {$context->path}");
$accessdata['loaded'][] = $context->path;
}
/**
* Add to the access ctrl array the data needed by a role for a given context.
*
* The data is added in the rdef key.
*
* This role-centric function is useful for role_switching
* and to get an overview of what a role gets under a
* given context and below...
*
* @global object
* @global object
* @param integer $roleid the id of the user
* @param object $context needs path!
* @param array $accessdata accessdata array NULL by default
* @return array
*/
function get_role_access_bycontext($roleid, $context, $accessdata=NULL) {
global $CFG, $DB;
/* Get the relevant rolecaps into rdef
* - relevant role caps
* - at ctx and above
* - below this ctx
*/
if (is_null($accessdata)) {
$accessdata = array(); // named list
$accessdata['ra'] = array();
$accessdata['rdef'] = array();
$accessdata['loaded'] = array();
}
$contexts = substr($context->path, 1); // kill leading slash
$contexts = str_replace('/', ',', $contexts);
//
// Walk up and down the tree to grab all the roledefs
// of interest to our role...
//
// NOTE: we use an IN clauses here - which
// might explode on huge sites with very convoluted nesting of
// categories... - extremely unlikely that the number of nested
// categories is so large that we hit the limits of IN()
//
$sql = "SELECT ctx.path, rc.capability, rc.permission
FROM {role_capabilities} rc
JOIN {context} ctx
ON rc.contextid=ctx.id
WHERE rc.roleid=? AND
( ctx.id IN ($contexts) OR
ctx.path LIKE ? )
ORDER BY ctx.depth ASC, ctx.path DESC, rc.roleid ASC ";
$params = array($roleid, $context->path."/%");
if ($rs = $DB->get_recordset_sql($sql, $params)) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
$rs->close();
}
return $accessdata;
}
/**
* Load accessdata for a user into the $ACCESSLIB_PRIVATE->accessdatabyuser global
*
* Used by has_capability() - but feel free
* to call it if you are about to run a BIG
* cron run across a bazillion users.
*
* @global object
* @global object
* @param int $userid
* @return array returns ACCESSLIB_PRIVATE->accessdatabyuser[userid]
*/
function load_user_accessdata($userid) {
global $CFG, $ACCESSLIB_PRIVATE;
$base = '/'.SYSCONTEXTID;
$accessdata = get_user_access_sitewide($userid);
$frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
//
// provide "default role" & set 'dr'
//
if (!empty($CFG->defaultuserroleid)) {
$accessdata = get_role_access($CFG->defaultuserroleid, $accessdata);
if (!isset($accessdata['ra'][$base])) {
$accessdata['ra'][$base] = array($CFG->defaultuserroleid);
} else {
array_push($accessdata['ra'][$base], $CFG->defaultuserroleid);
}
$accessdata['dr'] = $CFG->defaultuserroleid;
}
//
// provide "default frontpage role"
//
if (!empty($CFG->defaultfrontpageroleid)) {
$base = '/'. SYSCONTEXTID .'/'. $frontpagecontext->id;
$accessdata = get_default_frontpage_role_access($CFG->defaultfrontpageroleid, $accessdata);
if (!isset($accessdata['ra'][$base])) {
$accessdata['ra'][$base] = array($CFG->defaultfrontpageroleid);
} else {
array_push($accessdata['ra'][$base], $CFG->defaultfrontpageroleid);
}
}
// for dirty timestamps in cron
$accessdata['time'] = time();
$ACCESSLIB_PRIVATE->accessdatabyuser[$userid] = $accessdata;
compact_rdefs($ACCESSLIB_PRIVATE->accessdatabyuser[$userid]['rdef']);
return $ACCESSLIB_PRIVATE->accessdatabyuser[$userid];
}
/**
* Use shared copy of role definistions stored in ACCESSLIB_PRIVATE->roledefinitions;
*
* @global object
* @param array $rdefs array of role definitions in contexts
*/
function compact_rdefs(&$rdefs) {
global $ACCESSLIB_PRIVATE;
/*
* This is a basic sharing only, we could also
* use md5 sums of values. The main purpose is to
* reduce mem in cron jobs - many users in $ACCESSLIB_PRIVATE->accessdatabyuser array.
*/
foreach ($rdefs as $key => $value) {
if (!array_key_exists($key, $ACCESSLIB_PRIVATE->roledefinitions)) {
$ACCESSLIB_PRIVATE->roledefinitions[$key] = $rdefs[$key];
}
$rdefs[$key] =& $ACCESSLIB_PRIVATE->roledefinitions[$key];
}
}
/**
* A convenience function to completely load all the capabilities
* for the current user. This is what gets called from complete_user_login()
* for example. Call it only _after_ you've setup $USER and called
* check_enrolment_plugins();
* @see check_enrolment_plugins()
*
* @global object
* @global object
* @global object
*/
function load_all_capabilities() {
global $USER, $CFG, $ACCESSLIB_PRIVATE;
// roles not installed yet - we are in the middle of installation
if (during_initial_install()) {
return;
}
$base = '/'.SYSCONTEXTID;
if (isguestuser()) {
$guest = get_guest_role();
// Load the rdefs
$USER->access = get_role_access($guest->id);
// Put the ghost enrolment in place...
$USER->access['ra'][$base] = array($guest->id);
} else if (isloggedin()) {
$accessdata = get_user_access_sitewide($USER->id);
//
// provide "default role" & set 'dr'
//
if (!empty($CFG->defaultuserroleid)) {
$accessdata = get_role_access($CFG->defaultuserroleid, $accessdata);
if (!isset($accessdata['ra'][$base])) {
$accessdata['ra'][$base] = array($CFG->defaultuserroleid);
} else {
array_push($accessdata['ra'][$base], $CFG->defaultuserroleid);
}
$accessdata['dr'] = $CFG->defaultuserroleid;
}
$frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
//
// provide "default frontpage role"
//
if (!empty($CFG->defaultfrontpageroleid)) {
$base = '/'. SYSCONTEXTID .'/'. $frontpagecontext->id;
$accessdata = get_default_frontpage_role_access($CFG->defaultfrontpageroleid, $accessdata);
if (!isset($accessdata['ra'][$base])) {
$accessdata['ra'][$base] = array($CFG->defaultfrontpageroleid);
} else {
array_push($accessdata['ra'][$base], $CFG->defaultfrontpageroleid);
}
}
$USER->access = $accessdata;
} else if (!empty($CFG->notloggedinroleid)) {
$USER->access = get_role_access($CFG->notloggedinroleid);
$USER->access['ra'][$base] = array($CFG->notloggedinroleid);
}
// Timestamp to read dirty context timestamps later
$USER->access['time'] = time();
$ACCESSLIB_PRIVATE->dirtycontexts = array();
// Clear to force a refresh
unset($USER->mycourses);
}
/**
* A convenience function to completely reload all the capabilities
* for the current user when roles have been updated in a relevant
* context -- but PRESERVING switchroles and loginas.
*
* That is - completely transparent to the user.
*
* Note: rewrites $USER->access completely.
*
* @global object
* @global object
*/
function reload_all_capabilities() {
global $USER, $DB;
// error_log("reloading");
// copy switchroles
$sw = array();
if (isset($USER->access['rsw'])) {
$sw = $USER->access['rsw'];
// error_log(print_r($sw,1));
}
unset($USER->access);
unset($USER->mycourses);
load_all_capabilities();
foreach ($sw as $path => $roleid) {
$context = $DB->get_record('context', array('path'=>$path));
role_switch($roleid, $context);
}
}
/**
* Adds a temp role to an accessdata array.
*
* Useful for the "temporary guest" access
* we grant to logged-in users.
*
* Note - assumes a course context!
*
* @global object
* @global object
* @param object $content
* @param int $roleid
* @param array $accessdata
* @return array Returns access data
*/
function load_temp_role($context, $roleid, $accessdata) {
global $CFG, $DB;
//
// Load rdefs for the role in -
// - this context
// - all the parents
// - and below - IOWs overrides...
//
// turn the path into a list of context ids
$contexts = substr($context->path, 1); // kill leading slash
$contexts = str_replace('/', ',', $contexts);
$sql = "SELECT ctx.path, rc.capability, rc.permission
FROM {context} ctx
JOIN {role_capabilities} rc
ON rc.contextid=ctx.id
WHERE (ctx.id IN ($contexts)
OR ctx.path LIKE ?)
AND rc.roleid = ?
ORDER BY ctx.depth, ctx.path";
$params = array($context->path."/%", $roleid);
if ($rs = $DB->get_recordset_sql($sql, $params)) {
foreach ($rs as $rd) {
$k = "{$rd->path}:{$roleid}";
$accessdata['rdef'][$k][$rd->capability] = $rd->permission;
}
$rs->close();
}
//
// Say we loaded everything for the course context
// - which we just did - if the user gets a proper
// RA in this session, this data will need to be reloaded,
// but that is handled by the complete accessdata reload
//
array_push($accessdata['loaded'], $context->path);
//
// Add the ghost RA
//
if (isset($accessdata['ra'][$context->path])) {
array_push($accessdata['ra'][$context->path], $roleid);
} else {
$accessdata['ra'][$context->path] = array($roleid);
}
return $accessdata;
}
/**
* Check all the login enrolment information for the given user object
* by querying the enrolment plugins
*
* @global object
* @param object $user
* @return void
*/
function check_enrolment_plugins(&$user) {
global $CFG;
if (empty($user->id) or isguestuser($user)) {
// shortcut - there is no enrolment work for guests and not-logged-in users
return;
}
static $inprogress = array(); // To prevent this function being called more than once in an invocation
if (!empty($inprogress[$user->id])) {
return;
}
$inprogress[$user->id] = true; // Set the flag
require_once($CFG->dirroot .'/enrol/enrol.class.php');
if (!($plugins = explode(',', $CFG->enrol_plugins_enabled))) {
$plugins = array($CFG->enrol);
}
foreach ($plugins as $plugin) {
$enrol = enrolment_factory::factory($plugin);
if (method_exists($enrol, 'setup_enrolments')) { /// Plugin supports Roles (Moodle 1.7 and later)
$enrol->setup_enrolments($user);
} else { /// Run legacy enrolment methods
if (method_exists($enrol, 'get_student_courses')) {
$enrol->get_student_courses($user);
}
if (method_exists($enrol, 'get_teacher_courses')) {
$enrol->get_teacher_courses($user);
}
/// deal with $user->students and $user->teachers stuff
unset($user->student);
unset($user->teacher);
}
unset($enrol);
}
unset($inprogress[$user->id]); // Unset the flag
}
/**
* Returns array of all role archetypes.
*
* @return array
*/
function get_role_archetypes() {
return array(
'manager' => 'manager',
'coursecreator' => 'coursecreator',
'editingteacher' => 'editingteacher',
'teacher' => 'teacher',
'student' => 'student',
'guest' => 'guest',
'user' => 'user',
'frontpage' => 'frontpage'
);
}
/**
* Assign the defaults found in this capabality definition to roles that have
* the corresponding legacy capabilities assigned to them.
*
* @param string $capability
* @param array $legacyperms an array in the format (example):
* 'guest' => CAP_PREVENT,
* 'student' => CAP_ALLOW,
* 'teacher' => CAP_ALLOW,
* 'editingteacher' => CAP_ALLOW,
* 'coursecreator' => CAP_ALLOW,
* 'manager' => CAP_ALLOW
* @return boolean success or failure.
*/
function assign_legacy_capabilities($capability, $legacyperms) {
$archetypes = get_role_archetypes();
foreach ($legacyperms as $type => $perm) {
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
if ($type === 'admin') {
debugging('Legacy type admin in access.php was renamed to manager, please update the code.');
$type = 'manager';
}
if (!array_key_exists($type, $archetypes)) {
print_error('invalidlegacy', '', '', $type);
}
if ($roles = get_archetype_roles($type)) {
foreach ($roles as $role) {
// Assign a site level capability.
if (!assign_capability($capability, $perm, $role->id, $systemcontext->id)) {
return false;
}
}
}
}
return true;
}
/**
* @param object $capability a capbility - a row from the capabilitites table.
* @return boolean whether this capability is safe - that is, wether people with the
* safeoverrides capability should be allowed to change it.
*/
function is_safe_capability($capability) {
return !((RISK_DATALOSS | RISK_MANAGETRUST | RISK_CONFIG | RISK_XSS | RISK_PERSONAL) & $capability->riskbitmask);
}
/**********************************
* Context Manipulation functions *
**********************************/
/**
* Create a new context record for use by all roles-related stuff
*
* Create a new context record for use by all roles-related stuff
* assumes that the caller has done the homework.
*
* @global object
* @global object
* @param int $contextlevel
* @param int $instanceid
* @param int $strictness
* @return object newly created context
*/
function create_context($contextlevel, $instanceid, $strictness=IGNORE_MISSING) {
global $CFG, $DB;
if ($contextlevel == CONTEXT_SYSTEM) {
return create_system_context();
}
$context = new object();
$context->contextlevel = $contextlevel;
$context->instanceid = $instanceid;
// Define $context->path based on the parent
// context. In other words... Who is your daddy?
$basepath = '/' . SYSCONTEXTID;
$basedepth = 1;
$result = true;
$error_message = NULL;
switch ($contextlevel) {
case CONTEXT_COURSECAT:
$sql = "SELECT ctx.path, ctx.depth
FROM {context} ctx
JOIN {course_categories} cc
ON (cc.parent=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSECAT.")
WHERE cc.id=?";
$params = array($instanceid);
if ($p = $DB->get_record_sql($sql, $params)) {
$basepath = $p->path;
$basedepth = $p->depth;
} else if ($category = $DB->get_record('course_categories', array('id'=>$instanceid), '*', $strictness)) {
if (empty($category->parent)) {
// ok - this is a top category
} else if ($parent = get_context_instance(CONTEXT_COURSECAT, $category->parent)) {
$basepath = $parent->path;
$basedepth = $parent->depth;
} else {
// wrong parent category - no big deal, this can be fixed later
$basepath = NULL;
$basedepth = 0;
}
} else {
// incorrect category id
$error_message = "incorrect course category id ($instanceid)";
$result = false;
}
break;
case CONTEXT_COURSE:
$sql = "SELECT ctx.path, ctx.depth
FROM {context} ctx
JOIN {course} c
ON (c.category=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSECAT.")
WHERE c.id=? AND c.id !=" . SITEID;
$params = array($instanceid);
if ($p = $DB->get_record_sql($sql, $params)) {
$basepath = $p->path;
$basedepth = $p->depth;
} else if ($course = $DB->get_record('course', array('id'=>$instanceid), '*', $strictness)) {
if ($course->id == SITEID) {
//ok - no parent category
} else if ($parent = get_context_instance(CONTEXT_COURSECAT, $course->category)) {
$basepath = $parent->path;
$basedepth = $parent->depth;
} else {
// wrong parent category of course - no big deal, this can be fixed later
$basepath = NULL;
$basedepth = 0;
}
} else if ($instanceid == SITEID) {
// no errors for missing site course during installation
return false;
} else {
// incorrect course id
$error_message = "incorrect course id ($instanceid)";
$result = false;
}
break;
case CONTEXT_MODULE:
$sql = "SELECT ctx.path, ctx.depth
FROM {context} ctx
JOIN {course_modules} cm
ON (cm.course=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
WHERE cm.id=?";
$params = array($instanceid);
if ($p = $DB->get_record_sql($sql, $params)) {
$basepath = $p->path;
$basedepth = $p->depth;
} else if ($cm = $DB->get_record('course_modules', array('id'=>$instanceid), '*', $strictness)) {
if ($parent = get_context_instance(CONTEXT_COURSE, $cm->course, $strictness)) {
$basepath = $parent->path;
$basedepth = $parent->depth;
} else {
// course does not exist - modules can not exist without a course
$error_message = "course does not exist ($cm->course) - modules can not exist without a course";
$result = false;
}
} else {
// cm does not exist
$error_message = "cm with id $instanceid does not exist";
$result = false;
}
break;
case CONTEXT_BLOCK:
$sql = "SELECT ctx.path, ctx.depth
FROM {context} ctx
JOIN {block_instances} bi ON (bi.parentcontextid=ctx.id)
WHERE bi.id = ?";
$params = array($instanceid, CONTEXT_COURSE);
if ($p = $DB->get_record_sql($sql, $params, '*', $strictness)) {
$basepath = $p->path;
$basedepth = $p->depth;
} else {
// block does not exist
$error_message = 'block or parent context does not exist';
$result = false;
}
break;
case CONTEXT_USER:
// default to basepath
break;
}
// if grandparents unknown, maybe rebuild_context_path() will solve it later
if ($basedepth != 0) {
$context->depth = $basedepth+1;
}
if (!$result) {
debugging('Error: could not insert new context level "'.
s($contextlevel).'", instance "'.
s($instanceid).'". ' . $error_message);
return false;
}
$id = $DB->insert_record('context', $context);
// can't set the full path till we know the id!
if ($basedepth != 0 and !empty($basepath)) {
$DB->set_field('context', 'path', $basepath.'/'. $id, array('id'=>$id));
}
return get_context_instance_by_id($id);
}
/**
* Returns system context or NULL if can not be created yet.
*
* @todo can not use get_record() because we do not know if query failed :-(
* switch to get_record() later
*
* @global object
* @global object
* @param bool $cache use caching
* @return mixed system context or NULL
*/
function get_system_context($cache=true) {
global $DB, $ACCESSLIB_PRIVATE;
if ($cache and defined('SYSCONTEXTID')) {
if (is_null($ACCESSLIB_PRIVATE->systemcontext)) {
$ACCESSLIB_PRIVATE->systemcontext = new object();
$ACCESSLIB_PRIVATE->systemcontext->id = SYSCONTEXTID;
$ACCESSLIB_PRIVATE->systemcontext->contextlevel = CONTEXT_SYSTEM;
$ACCESSLIB_PRIVATE->systemcontext->instanceid = 0;
$ACCESSLIB_PRIVATE->systemcontext->path = '/'.SYSCONTEXTID;
$ACCESSLIB_PRIVATE->systemcontext->depth = 1;
}
return $ACCESSLIB_PRIVATE->systemcontext;
}
try {
$context = $DB->get_record('context', array('contextlevel'=>CONTEXT_SYSTEM));
} catch (dml_exception $e) {
//table does not exist yet, sorry
return NULL;
}
if (!$context) {
$context = new object();
$context->contextlevel = CONTEXT_SYSTEM;
$context->instanceid = 0;
$context->depth = 1;
$context->path = NULL; //not known before insert
try {
$context->id = $DB->insert_record('context', $context);
} catch (dml_exception $e) {
// can not create context yet, sorry
return NULL;
}
}
if (!isset($context->depth) or $context->depth != 1 or $context->instanceid != 0 or $context->path != '/'.$context->id) {
$context->instanceid = 0;
$context->path = '/'.$context->id;
$context->depth = 1;
$DB->update_record('context', $context);
}
if (!defined('SYSCONTEXTID')) {
define('SYSCONTEXTID', $context->id);
}
$ACCESSLIB_PRIVATE->systemcontext = $context;
return $ACCESSLIB_PRIVATE->systemcontext;
}
/**
* Remove a context record and any dependent entries,
* removes context from static context cache too
*
* @global object
* @global object
* @param int $level
* @param int $instanceid
* @return bool properly deleted
*/
function delete_context($contextlevel, $instanceid) {
global $DB, $ACCESSLIB_PRIVATE, $CFG;
// do not use get_context_instance(), because the related object might not exist,
// or the context does not exist yet and it would be created now
if ($context = $DB->get_record('context', array('contextlevel'=>$contextlevel, 'instanceid'=>$instanceid))) {
$result = $DB->delete_records('role_assignments', array('contextid'=>$context->id)) &&
$DB->delete_records('role_capabilities', array('contextid'=>$context->id)) &&
$DB->delete_records('context', array('id'=>$context->id)) &&
$DB->delete_records('role_names', array('contextid'=>$context->id));
// do not mark dirty contexts if parents unknown
if (!is_null($context->path) and $context->depth > 0) {
mark_context_dirty($context->path);
}
// purge static context cache if entry present
unset($ACCESSLIB_PRIVATE->contexts[$contextlevel][$instanceid]);
unset($ACCESSLIB_PRIVATE->contextsbyid[$context->id]);
blocks_delete_all_for_context($context->id);
filter_delete_all_for_context($context->id);
return $result;
} else {
return true;
}
}
/**
* Precreates all contexts including all parents
*
* @global object
* @param int $contextlevel empty means all
* @param bool $buildpaths update paths and depths
* @return void
*/
function create_contexts($contextlevel=NULL, $buildpaths=true) {
global $DB;
//make sure system context exists
$syscontext = get_system_context(false);
if (empty($contextlevel) or $contextlevel == CONTEXT_COURSECAT
or $contextlevel == CONTEXT_COURSE
or $contextlevel == CONTEXT_MODULE
or $contextlevel == CONTEXT_BLOCK) {
$sql = "INSERT INTO {context} (contextlevel, instanceid)
SELECT ".CONTEXT_COURSECAT.", cc.id
FROM {course}_categories cc
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE cc.id = cx.instanceid AND cx.contextlevel=".CONTEXT_COURSECAT.")";
$DB->execute($sql);
}
if (empty($contextlevel) or $contextlevel == CONTEXT_COURSE
or $contextlevel == CONTEXT_MODULE
or $contextlevel == CONTEXT_BLOCK) {
$sql = "INSERT INTO {context} (contextlevel, instanceid)
SELECT ".CONTEXT_COURSE.", c.id
FROM {course} c
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE c.id = cx.instanceid AND cx.contextlevel=".CONTEXT_COURSE.")";
$DB->execute($sql);
}
if (empty($contextlevel) or $contextlevel == CONTEXT_MODULE
or $contextlevel == CONTEXT_BLOCK) {
$sql = "INSERT INTO {context} (contextlevel, instanceid)
SELECT ".CONTEXT_MODULE.", cm.id
FROM {course}_modules cm
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE cm.id = cx.instanceid AND cx.contextlevel=".CONTEXT_MODULE.")";
$DB->execute($sql);
}
if (empty($contextlevel) or $contextlevel == CONTEXT_USER
or $contextlevel == CONTEXT_BLOCK) {
$sql = "INSERT INTO {context} (contextlevel, instanceid)
SELECT ".CONTEXT_USER.", u.id
FROM {user} u
WHERE u.deleted=0
AND NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE u.id = cx.instanceid AND cx.contextlevel=".CONTEXT_USER.")";
$DB->execute($sql);
}
if (empty($contextlevel) or $contextlevel == CONTEXT_BLOCK) {
$sql = "INSERT INTO {context} (contextlevel, instanceid)
SELECT ".CONTEXT_BLOCK.", bi.id
FROM {block_instances} bi
WHERE NOT EXISTS (SELECT 'x'
FROM {context} cx
WHERE bi.id = cx.instanceid AND cx.contextlevel=".CONTEXT_BLOCK.")";
$DB->execute($sql);
}
if ($buildpaths) {
build_context_path(false);
}
}
/**
* Remove stale context records
*
* @global object
* @return bool
*/
function cleanup_contexts() {
global $DB;
$sql = " SELECT c.contextlevel,
c.instanceid AS instanceid
FROM {context} c
LEFT OUTER JOIN {course}_categories t
ON c.instanceid = t.id
WHERE t.id IS NULL AND c.contextlevel = ".CONTEXT_COURSECAT."
UNION
SELECT c.contextlevel,
c.instanceid
FROM {context} c
LEFT OUTER JOIN {course} t
ON c.instanceid = t.id
WHERE t.id IS NULL AND c.contextlevel = ".CONTEXT_COURSE."
UNION
SELECT c.contextlevel,
c.instanceid
FROM {context} c
LEFT OUTER JOIN {course}_modules t
ON c.instanceid = t.id
WHERE t.id IS NULL AND c.contextlevel = ".CONTEXT_MODULE."
UNION
SELECT c.contextlevel,
c.instanceid
FROM {context} c
LEFT OUTER JOIN {user} t
ON c.instanceid = t.id
WHERE t.id IS NULL AND c.contextlevel = ".CONTEXT_USER."
UNION
SELECT c.contextlevel,
c.instanceid
FROM {context} c
LEFT OUTER JOIN {block_instances} t
ON c.instanceid = t.id
WHERE t.id IS NULL AND c.contextlevel = ".CONTEXT_BLOCK."
";
// transactions used only for performance reasons here
$transaction = $DB->start_delegated_transaction();
if ($rs = $DB->get_recordset_sql($sql)) {
foreach ($rs as $ctx) {
delete_context($ctx->contextlevel, $ctx->instanceid);
}
$rs->close();
}
$transaction->allow_commit();
return true;
}
/**
* Preloads all contexts relating to a course: course, modules. Block contexts
* are no longer loaded here. The contexts for all the blocks on the current
* page are now efficiently loaded by {@link block_manager::load_blocks()}.
*
* @param int $courseid Course ID
* @return void
*/
function preload_course_contexts($courseid) {
global $DB, $ACCESSLIB_PRIVATE;
// Users can call this multiple times without doing any harm
global $ACCESSLIB_PRIVATE;
if (array_key_exists($courseid, $ACCESSLIB_PRIVATE->preloadedcourses)) {
return;
}
$params = array($courseid, $courseid, $courseid);
$sql = "SELECT x.instanceid, x.id, x.contextlevel, x.path, x.depth
FROM {course_modules} cm
JOIN {context} x ON x.instanceid=cm.id
WHERE cm.course=? AND x.contextlevel=".CONTEXT_MODULE."
UNION ALL
SELECT x.instanceid, x.id, x.contextlevel, x.path, x.depth
FROM {context} x
WHERE x.instanceid=? AND x.contextlevel=".CONTEXT_COURSE."";
$rs = $DB->get_recordset_sql($sql, $params);
foreach($rs as $context) {
cache_context($context);
}
$rs->close();
$ACCESSLIB_PRIVATE->preloadedcourses[$courseid] = true;
}
/**
* Get the context instance as an object. This function will create the
* context instance if it does not exist yet.
*
* @todo Remove code branch from previous fix MDL-9016 which is no longer needed
*
* @param integer $level The context level, for example CONTEXT_COURSE, or CONTEXT_MODULE.
* @param integer $instance The instance id. For $level = CONTEXT_COURSE, this would be $course->id,
* for $level = CONTEXT_MODULE, this would be $cm->id. And so on. Defaults to 0
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
* MUST_EXIST means throw exception if no record or multiple records found
* @return object The context object.
*/
function get_context_instance($contextlevel, $instance=0, $strictness=IGNORE_MISSING) {
global $DB, $ACCESSLIB_PRIVATE;
static $allowed_contexts = array(CONTEXT_SYSTEM, CONTEXT_USER, CONTEXT_COURSECAT, CONTEXT_COURSE, CONTEXT_MODULE, CONTEXT_BLOCK);
if ($contextlevel === 'clearcache') {
// TODO: Remove for v2.0
// No longer needed, but we'll catch it to avoid erroring out on custom code.
// This used to be a fix for MDL-9016
// "Restoring into existing course, deleting first
// deletes context and doesn't recreate it"
return false;
}
/// System context has special cache
if ($contextlevel == CONTEXT_SYSTEM) {
return get_system_context();
}
/// check allowed context levels
if (!in_array($contextlevel, $allowed_contexts)) {
// fatal error, code must be fixed - probably typo or switched parameters
print_error('invalidcourselevel');
}
if (!is_array($instance)) {
/// Check the cache
if (isset($ACCESSLIB_PRIVATE->contexts[$contextlevel][$instance])) { // Already cached
return $ACCESSLIB_PRIVATE->contexts[$contextlevel][$instance];
}
/// Get it from the database, or create it
if (!$context = $DB->get_record('context', array('contextlevel'=>$contextlevel, 'instanceid'=>$instance))) {
$context = create_context($contextlevel, $instance, $strictness);
}
/// Only add to cache if context isn't empty.
if (!empty($context)) {
cache_context($context);
}
return $context;
}
/// ok, somebody wants to load several contexts to save some db queries ;-)
$instances = $instance;
$result = array();
foreach ($instances as $key=>$instance) {
/// Check the cache first
if (isset($ACCESSLIB_PRIVATE->contexts[$contextlevel][$instance])) { // Already cached
$result[$instance] = $ACCESSLIB_PRIVATE->contexts[$contextlevel][$instance];
unset($instances[$key]);
continue;
}
}
if ($instances) {
list($instanceids, $params) = $DB->get_in_or_equal($instances, SQL_PARAMS_QM);
array_unshift($params, $contextlevel);
$sql = "SELECT instanceid, id, contextlevel, path, depth
FROM {context}
WHERE contextlevel=? AND instanceid $instanceids";
if (!$contexts = $DB->get_records_sql($sql, $params)) {
$contexts = array();
}
foreach ($instances as $instance) {
if (isset($contexts[$instance])) {
$context = $contexts[$instance];
} else {
$context = create_context($contextlevel, $instance);
}
if (!empty($context)) {
cache_context($context);
}
$result[$instance] = $context;
}
}
return $result;
}
/**
* Get a context instance as an object, from a given context id.
*
* @param mixed $id a context id or array of ids.
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
* MUST_EXIST means throw exception if no record or multiple records found
* @return mixed object, array of the context object, or false.
*/
function get_context_instance_by_id($id, $strictness=IGNORE_MISSING) {
global $DB, $ACCESSLIB_PRIVATE;
if ($id == SYSCONTEXTID) {
return get_system_context();
}
if (isset($ACCESSLIB_PRIVATE->contextsbyid[$id])) { // Already cached
return $ACCESSLIB_PRIVATE->contextsbyid[$id];
}
if ($context = $DB->get_record('context', array('id'=>$id), '*', $strictness)) {
cache_context($context);
return $context;
}
return false;
}
/**
* Get the local override (if any) for a given capability in a role in a context
*
* @global object
* @param int $roleid
* @param int $contextid
* @param string $capability
*/
function get_local_override($roleid, $contextid, $capability) {
global $DB;
return $DB->get_record('role_capabilities', array('roleid'=>$roleid, 'capability'=>$capability, 'contextid'=>$contextid));
}
/**
* Returns context instance plus related course and cm instances
* @param int $contextid
* @return array of ($context, $course, $cm)
*/
function get_context_info_array($contextid) {
global $DB;
$context = get_context_instance_by_id($contextid, MUST_EXIST);
$course = NULL;
$cm = NULL;
if ($context->contextlevel == CONTEXT_COURSE) {
$course = $DB->get_record('course', array('id'=>$context->instanceid), '*', MUST_EXIST);
} else if ($context->contextlevel == CONTEXT_MODULE) {
$cm = get_coursemodule_from_id('', $context->instanceid, 0, false, MUST_EXIST);
$course = $DB->get_record('course', array('id'=>$cm->course), '*', MUST_EXIST);
} else if ($context->contextlevel == CONTEXT_BLOCK) {
$parentcontexts = get_parent_contexts($context, false);
$parent = reset($parentcontexts);
$parent = get_context_instance_by_id($parent);
if ($parent->contextlevel == CONTEXT_COURSE) {
$course = $DB->get_record('course', array('id'=>$parent->instanceid), '*', MUST_EXIST);
} else if ($parent->contextlevel == CONTEXT_MODULE) {
$cm = get_coursemodule_from_id('', $parent->instanceid, 0, false, MUST_EXIST);
$course = $DB->get_record('course', array('id'=>$cm->course), '*', MUST_EXIST);
}
}
return array($context, $course, $cm);
}
//////////////////////////////////////
// DB TABLE RELATED FUNCTIONS //
//////////////////////////////////////
/**
* function that creates a role
*
* @global object
* @param string $name role name
* @param string $shortname role short name
* @param string $description role description
* @param string $archetype
* @return mixed id or dml_exception
*/
function create_role($name, $shortname, $description, $archetype='') {
global $DB;
if (strpos($archetype, 'moodle/legacy:') !== false) {
throw new coding_exception('Use new role archetype parameter in create_role() instead of old legacy capabilities.');
}
// verify role archetype actually exists
$archetypes = get_role_archetypes();
if (empty($archetypes[$archetype])) {
$archetype = '';
}
// Get the system context.
$context = get_context_instance(CONTEXT_SYSTEM);
// Insert the role record.
$role = new object();
$role->name = $name;
$role->shortname = $shortname;
$role->description = $description;
$role->archetype = $archetype;
//find free sortorder number
$role->sortorder = $DB->get_field('role', 'MAX(sortorder) + 1', array());
if (empty($role->sortorder)) {
$role->sortorder = 1;
}
$id = $DB->insert_record('role', $role);
return $id;
}
/**
* Function that deletes a role and cleanups up after it
*
* @param int $roleid id of role to delete
* @return bool lways true
*/
function delete_role($roleid) {
global $CFG, $DB;
// first unssign all users
role_unassign($roleid);
// cleanup all references to this role, ignore errors
$DB->delete_records('role_capabilities', array('roleid'=>$roleid));
$DB->delete_records('role_allow_assign', array('roleid'=>$roleid));
$DB->delete_records('role_allow_assign', array('allowassign'=>$roleid));
$DB->delete_records('role_allow_override', array('roleid'=>$roleid));
$DB->delete_records('role_allow_override', array('allowoverride'=>$roleid));
$DB->delete_records('role_names', array('roleid'=>$roleid));
$DB->delete_records('role_context_levels', array('roleid'=>$roleid));
// finally delete the role itself
// get this before the name is gone for logging
$rolename = $DB->get_field('role', 'name', array('id'=>$roleid));
$DB->delete_records('role', array('id'=>$roleid));
add_to_log(SITEID, 'role', 'delete', 'admin/roles/action=delete&roleid='.$roleid, $rolename, '');
return true;
}
/**
* Function to write context specific overrides, or default capabilities.
*
* @global object
* @global object
* @param string module string name
* @param string capability string name
* @param int contextid context id
* @param int roleid role id
* @param int permission int 1,-1 or -1000 should not be writing if permission is 0
* @return bool
*/
function assign_capability($capability, $permission, $roleid, $contextid, $overwrite=false) {
global $USER, $DB;
if (empty($permission) || $permission == CAP_INHERIT) { // if permission is not set
unassign_capability($capability, $roleid, $contextid);
return true;
}
$existing = $DB->get_record('role_capabilities', array('contextid'=>$contextid, 'roleid'=>$roleid, 'capability'=>$capability));
if ($existing and !$overwrite) { // We want to keep whatever is there already
return true;
}
$cap = new object;
$cap->contextid = $contextid;
$cap->roleid = $roleid;
$cap->capability = $capability;
$cap->permission = $permission;
$cap->timemodified = time();
$cap->modifierid = empty($USER->id) ? 0 : $USER->id;
if ($existing) {
$cap->id = $existing->id;
$DB->update_record('role_capabilities', $cap);
} else {
$c = $DB->get_record('context', array('id'=>$contextid));
$DB->insert_record('role_capabilities', $cap);
}
return true;
}
/**
* Unassign a capability from a role.
*
* @global object
* @param int $roleid the role id
* @param string $capability the name of the capability
* @return boolean success or failure
*/
function unassign_capability($capability, $roleid, $contextid=NULL) {
global $DB;
if (!empty($contextid)) {
// delete from context rel, if this is the last override in this context
$DB->delete_records('role_capabilities', array('capability'=>$capability, 'roleid'=>$roleid, 'contextid'=>$contextid));
} else {
$DB->delete_records('role_capabilities', array('capability'=>$capability, 'roleid'=>$roleid));
}
return true;
}
/**
* Get the roles that have a given capability assigned to it
* Get the roles that have a given capability assigned to it. This function
* does not resolve the actual permission of the capability. It just checks
* for assignment only.
*
* @global object
* @global object
* @param string $capability - capability name (string)
* @param string $permission - optional, the permission defined for this capability
* either CAP_ALLOW, CAP_PREVENT or CAP_PROHIBIT. Defaults to NULL
* @param object $contect
* @return mixed array or role objects
*/
function get_roles_with_capability($capability, $permission=NULL, $context=NULL) {
global $CFG, $DB;
$params = array();
if ($context) {
if ($contexts = get_parent_contexts($context)) {
$listofcontexts = '('.implode(',', $contexts).')';
} else {
$sitecontext = get_context_instance(CONTEXT_SYSTEM);
$listofcontexts = '('.$sitecontext->id.')'; // must be site
}
$contextstr = "AND (rc.contextid = ? OR rc.contextid IN $listofcontexts)";
$params[] = $context->id;
} else {
$contextstr = '';
}
$selectroles = "SELECT r.*
FROM {role} r,
{role_capabilities} rc
WHERE rc.capability = ?
AND rc.roleid = r.id $contextstr";
array_unshift($params, $capability);
if (isset($permission)) {
$selectroles .= " AND rc.permission = ?";
$params[] = $permission;
}
return $DB->get_records_sql($selectroles, $params);
}
/**
* This function makes a role-assignment (a role for a user or group in a particular context)
*
* @param int $roleid the role of the id
* @param int $userid userid
* @param int $groupid_ignored - never implemented!
* @param int $contextid id of the context
* @param int $timestart time this assignment becomes effective defaults to 0
* @param int $timeend time this assignemnt ceases to be effective defaults to 0
* @param int $hidden_ignored - use roels with moodle/course:view capability or enrolemnt instead
* @param string $enrol defaults to 'manual'
* @param string $timemodified defaults to ''
* @return int new id of the assigment
*/
function role_assign($roleid, $userid, $groupid_ignored, $contextid, $timestart=0, $timeend=0, $hidden_ignored=0, $enrol='manual',$timemodified='') {
global $USER, $CFG, $DB;
/// Do some data validation
if (empty($roleid)) {
debugging('Role ID not provided');
return false;
}
if (empty($userid)) {
debugging('Userid or groupid must be provided');
return false;
}
if ($userid && !$DB->record_exists('user', array('id'=>$userid))) {
debugging('User ID '.intval($userid).' does not exist!');
return false;
}
if (!$context = get_context_instance_by_id($contextid)) {
debugging('Context ID '.intval($contextid).' does not exist!');
return false;
}
if (($timestart and $timeend) and ($timestart > $timeend)) {
debugging('The end time can not be earlier than the start time');
return false;
}
if (!$timemodified) {
$timemodified = time();
}
/// Check for existing entry
$ra = $DB->get_record('role_assignments', array('roleid'=>$roleid, 'contextid'=>$context->id, 'userid'=>$userid));
if (empty($ra)) { // Create a new entry
$ra = new object();
$ra->roleid = $roleid;
$ra->contextid = $context->id;
$ra->userid = $userid;
$ra->enrol = $enrol;
/// Always round timestart downto 100 secs to help DBs to use their own caching algorithms
/// by repeating queries with the same exact parameters in a 100 secs time window
$ra->timestart = round($timestart, -2);
$ra->timeend = $timeend;
$ra->timemodified = $timemodified;
$ra->modifierid = empty($USER->id) ? 0 : $USER->id;
$ra->id = $DB->insert_record('role_assignments', $ra);
} else { // We already have one, just update it
$ra->id = $ra->id;
$ra->enrol = $enrol;
/// Always round timestart downto 100 secs to help DBs to use their own caching algorithms
/// by repeating queries with the same exact parameters in a 100 secs time window
$ra->timestart = round($timestart, -2);
$ra->timeend = $timeend;
$ra->timemodified = $timemodified;
$ra->modifierid = empty($USER->id) ? 0 : $USER->id;
$DB->update_record('role_assignments', $ra);
}
/// mark context as dirty - modules might use has_capability() in xxx_role_assing()
/// again expensive, but needed
mark_context_dirty($context->path);
if (!empty($USER->id) && $USER->id == $userid) {
/// If the user is the current user, then do full reload of capabilities too.
load_all_capabilities();
}
/// Ask all the modules if anything needs to be done for this user
$mods = get_plugin_list('mod');
foreach ($mods as $mod => $moddir) {
include_once($moddir.'/lib.php');
$functionname = $mod.'_role_assign';
if (function_exists($functionname)) {
$functionname($userid, $context, $roleid);
}
}
/// now handle metacourse role assignments if in course context
if ($context->contextlevel == CONTEXT_COURSE) {
if ($parents = $DB->get_records('course_meta', array('child_course'=>$context->instanceid))) {
foreach ($parents as $parent) {
sync_metacourse($parent->parent_course);
}
}
}
events_trigger('role_assigned', $ra);
return $ra->id;
}
/**
* Deletes one or more role assignments. You must specify at least one parameter.
*
* @global object
* @global object
* @global object
* @param int $roleid defaults to 0
* @param int $userid defaults to 0
* @param int $groupid_ignored never implemented
* @param int $contextid defaults to 0
* @param mixed $enrol unassign only if enrolment type matches, NULL means anything. Defaults to NULL
* @return boolean success or failure
*/
function role_unassign($roleid=0, $userid=0, $groupid_ignored=0, $contextid=0, $enrol=NULL) {
global $USER, $CFG, $DB;
require_once($CFG->dirroot.'/group/lib.php');
$args = array('roleid', 'userid', 'contextid');
$select = array();
$params = array();
foreach ($args as $arg) {
if ($$arg) {
$select[] = "$arg = ?";
$params[] = $$arg;
}
}
if (!empty($enrol)) {
$select[] = "enrol=?";
$params[] = $enrol;
}
if ($select) {
if ($ras = $DB->get_records_select('role_assignments', implode(' AND ', $select), $params)) {
$mods = get_plugin_list('mod');
foreach($ras as $ra) {
/// infinite loop protection when deleting recursively
if (!$ra = $DB->get_record('role_assignments', array('id'=>$ra->id))) {
continue;
}
$DB->delete_records('role_assignments', array('id'=>$ra->id));
if (!$context = get_context_instance_by_id($ra->contextid)) {
// strange error, not much to do
continue;
}
/* mark contexts as dirty here, because we need the refreshed
* caps bellow to delete group membership and user_lastaccess!
* and yes, this is very expensive for bulk operations :-(
*/
mark_context_dirty($context->path);
/// If the user is the current user, then do full reload of capabilities too.
if (!empty($USER->id) && $USER->id == $ra->userid) {
load_all_capabilities();
}
/// Ask all the modules if anything needs to be done for this user
foreach ($mods as $mod=>$moddir) {
include_once($moddir.'/lib.php');
$functionname = $mod.'_role_unassign';
if (function_exists($functionname)) {
$functionname($ra->userid, $context); // watch out, $context might be NULL if something goes wrong
}
}
/// now handle metacourse role unassigment and removing from goups if in course context
if ($context->contextlevel == CONTEXT_COURSE) {
// cleanup leftover course groups/subscriptions etc when user has
// no capability to view course
// this may be slow, but this is the proper way of doing it
if (!has_capability('moodle/course:participate', $context, $ra->userid)) {
// remove from groups
groups_delete_group_members($context->instanceid, $ra->userid);
// delete lastaccess records
$DB->delete_records('user_lastaccess', array('userid'=>$ra->userid, 'courseid'=>$context->instanceid));
}
//unassign roles in metacourses if needed
if ($parents = $DB->get_records('course_meta', array('child_course'=>$context->instanceid))) {
foreach ($parents as $parent) {
sync_metacourse($parent->parent_course);
}
}
}
events_trigger('role_unassigned', $ra);
}
}
}
return true;
}
/**
* Enrol someone without using the default role in a course
*
* A convenience function to take care of the common case where you
* just want to enrol someone using the default role into a course
*
* @param object $course
* @param object $user
* @param string $enrol the plugin used to do this enrolment
* @return bool
*/
function enrol_into_course($course, $user, $enrol) {
$timestart = time();
// remove time part from the timestamp and keep only the date part
$timestart = make_timestamp(date('Y', $timestart), date('m', $timestart), date('d', $timestart), 0, 0, 0);
if ($course->enrolperiod) {
$timeend = $timestart + $course->enrolperiod;
} else {
$timeend = 0;
}
if ($role = get_default_course_role($course)) {
$context = get_context_instance(CONTEXT_COURSE, $course->id);
if (!role_assign($role->id, $user->id, 0, $context->id, $timestart, $timeend, 0, $enrol)) {
return false;
}
// force accessdata refresh for users visiting this context...
mark_context_dirty($context->path);
email_welcome_message_to_user($course, $user);
add_to_log($course->id, 'course', 'enrol',
'view.php?id='.$course->id, $course->id);
return true;
}
return false;
}
/**
* Determines if a user is currently logged in
*
* @return bool
*/
function isloggedin() {
global $USER;
return (!empty($USER->id));
}
/**
* Determines if a user is logged in as real guest user with username 'guest'.
*
* @param int $user mixed user object or id, $USER if not specified
* @return bool true if user is the real guest user, false if not logged in or other user
*/
function isguestuser($user = NULL) {
global $USER, $DB, $CFG;
// make sure we have the user id cached in config table, because we are going to use it a lot
if (empty($CFG->siteguest)) {
if (!$guestid = $DB->get_field('user', 'id', array('username'=>'guest', 'mnethostid'=>$CFG->mnet_localhost_id))) {
// guest does not exist yet, weird
return false;
}
set_config('siteguest', $guestid);
}
if ($user === NULL) {
$user = $USER;
}
if ($user === NULL) {
// happens when setting the $USER
return false;
} else if (is_numeric($user)) {
return ($CFG->siteguest == $user);
} else if (is_object($user)) {
if (empty($user->id)) {
return false; // not logged in means is not be guest
} else {
return ($CFG->siteguest == $user->id);
}
} else {
throw new coding_exception('Invalid user parameter supplied for isguestuser() function!');
}
}
/**
* Does user have a (temporary or real) guest access to course?
*
* @param object $context
* @param object|int $user
* @return bool
*/
function is_guest($context, $user = NULL) {
// first find the course context
$coursecontext = get_course_context($context);
// make sure there is a real user specified
if ($user === NULL) {
$userid = !empty($USER->id) ? $USER->id : 0;
} else {
$userid = !empty($user->id) ? $user->id : $user;
}
if (isguestuser($userid)) {
// can not inspect or be enrolled
return true;
}
if (has_capability('moodle/course:view', $coursecontext, $user)) {
// viewing users appear out of nowhere, they are neither guests nor participants
return false;
}
if (has_capability('moodle/course:participate', $coursecontext, $userid, false)) {
return false;
}
return true;
}
/**
* Returns true if user has course:inspect capability in course,
* this is intended for admins, managers (aka small admins), inspectors, etc.
*
* @param object $context
* @param int|object $user, if NULL $USER is used
* @param string $withcapability extra capability name
* @return bool
*/
function is_viewing($context, $user = NULL, $withcapability = '') {
global $USER;
// first find the course context
$coursecontext = get_course_context($context);
if (isguestuser($user)) {
// can not inspect
return false;
}
if (!has_capability('moodle/course:view', $coursecontext, $user)) {
// admins are allowed to inspect courses
return false;
}
if ($withcapability and !has_capability($withcapability, $context, $user)) {
// site admins always have the capability, but the enrolment above blocks
return false;
}
return true;
}
/**
* Returns true if user is enrolled (is participating) in course
* this is intended for students and teachers.
*
* @param object $context
* @param int|object $user, if NULL $USER is used, oherwise user object or id expected
* @param string $withcapability extra capability name
* @return bool
*/
function is_enrolled($context, $user = NULL, $withcapability = '') {
global $USER;
// first find the course context
$coursecontext = get_course_context($context);
// make sure there is a real user specified
if ($user === NULL) {
$userid = !empty($USER->id) ? $USER->id : 0;
} else {
$userid = !empty($user->id) ? $user->id : $user;
}
if (empty($userid)) {
// not-logged-in!
return false;
} else if (isguestuser($userid)) {
// guest account can not be enrolled anywhere
return false;
}
if ($coursecontext->instanceid != SITEID and !has_capability('moodle/course:participate', $coursecontext, $userid, false)) {
// admins are not enrolled, everybody is "enrolled" in the frontpage course
return false;
}
if ($withcapability and !has_capability($withcapability, $context, $userid)) {
return false;
}
return true;
}
/**
* Returns array with sql code and parameters returning all ids
* of users enrolled into course.
* @param object $context
* @param string $withcapability
* @param int $groupid 0 means ignore groups, any other value limits the result by group id
* @param string $prefix used for alias of user table, parameter names and in aliases of other used tables
* @return array list($sql, $params)
*/
function get_enrolled_sql($context, $withcapability = '', $groupid = 0, $prefix = 'eu') {
global $DB;
if ($context->contextlevel < CONTEXT_COURSE) {
throw new coding_exception('get_enrolled_sql() expects course context and bellow!');
}
// first find the course context
if ($context->contextlevel == CONTEXT_COURSE) {
$coursecontext = $context;
} else if ($context->contextlevel == CONTEXT_MODULE) {
$coursecontext = get_context_instance_by_id(get_parent_contextid($context, MUST_EXIST));
} else if ($context->contextlevel == CONTEXT_BLOCK) {
$parentcontext = get_context_instance_by_id(get_parent_contextid($context, MUST_EXIST));
if ($parentcontext->contextlevel == CONTEXT_COURSE) {
$coursecontext = $parentcontext;
} else if ($parentcontext->contextlevel == CONTEXT_MODULE) {
$coursecontext = get_context_instance_by_id(get_parent_contextid($parentcontext, MUST_EXIST));
} else {
throw new coding_exception('Invalid context supplied to get_enrolled_sql()!');
}
} else {
throw new coding_exception('Invalid context supplied to get_enrolled_sql()!');
}
list($contextids, $contextpaths) = get_context_info_list($context);
list($coursecontextids, $coursecontextpaths) = get_context_info_list($coursecontext);
// get all relevant capability info for all roles
if ($withcapability) {
list($incontexts, $params) = $DB->get_in_or_equal($contextids, SQL_PARAMS_NAMED, 'con00');
$incaps = "IN (:participate, :withcap)";
$params['participate'] = 'moodle/course:participate';
$params['withcap'] = $withcapability;
} else {
list($incontexts, $params) = $DB->get_in_or_equal($coursecontextids, SQL_PARAMS_NAMED, 'con00');
$incaps = "= :participate";
$params['participate'] = 'moodle/course:participate';
}
$defs = array();
$sql = "SELECT rc.id, rc.roleid, rc.permission, rc.capability, ctx.path
FROM {role_capabilities} rc
JOIN {context} ctx on rc.contextid = ctx.id
WHERE rc.contextid $incontexts AND rc.capability $incaps";
$rcs = $DB->get_records_sql($sql, $params);
foreach ($rcs as $rc) {
$defs[$rc->capability][$rc->path][$rc->roleid] = $rc->permission;
}
$courseaccess = array();
if (!empty($defs['moodle/course:participate'])) {
foreach ($coursecontextpaths as $path) {
if (empty($defs['moodle/course:participate'][$path])) {
continue;
}
foreach($defs['moodle/course:participate'][$path] as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
$courseaccess[$roleid] = CAP_PROHIBIT;
continue;
}
if (!isset($courseaccess[$roleid])) {
$courseaccess[$roleid] = (int)$perm;
}
}
}
}
$access = array();
if (!empty($defs[$withcapability])) {
foreach ($contextpaths as $path) {
if (empty($defs[$withcapability][$path])) {
continue;
}
foreach($defs[$withcapability][$path] as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
$access[$roleid] = CAP_PROHIBIT;
continue;
}
if (!isset($access[$roleid])) {
$access[$roleid] = (int)$perm;
}
}
}
}
unset($defs);
// make lists of roles that are needed and prohibited
$courseneeded = array(); // one of these is enough
$courseprohibited = array(); // must not have any of these
foreach ($courseaccess as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
unset($courseneeded[$roleid]);
$courseprohibited[$roleid] = true;
} else if ($perm == CAP_ALLOW and empty($courseprohibited[$roleid])) {
$courseneeded[$roleid] = true;
}
}
$needed = array(); // one of these is enough
$prohibited = array(); // must not have any of these
if ($withcapability) {
foreach ($access as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
unset($needed[$roleid]);
$prohibited[$roleid] = true;
} else if ($perm == CAP_ALLOW and empty($prohibited[$roleid])) {
$needed[$roleid] = true;
}
}
}
$isfrontpage = ($coursecontext->instanceid == SITEID);
$defaultuserroleid = isset($CFG->defaultuserroleid) ? $CFG->defaultuserroleid : NULL;
$defaultfrontpageroleid = isset($CFG->defaultfrontpageroleid) ? $CFG->defaultfrontpageroleid : NULL;
$nobody = false;
if ($isfrontpage) {
// on the frontpage all users are kind of enrolled, we have to respect only the prohibits
$courseneeded = array();
} else {
if (empty($courseneeded)) {
$nobody = true;
}
}
if ($withcapability and !$nobody) {
if ($isfrontpage) {
if (!empty($prohibited[$defaultuserroleid]) or !empty($prohibited[$defaultfrontpageroleid])) {
$nobody = true;
} else if (!empty($neded[$defaultuserroleid]) or !empty($neded[$defaultfrontpageroleid])) {
// everybody not having prohibit has the capability
$needed = array();
} else if (empty($needed)) {
$nobody = true;
}
} else {
if (!empty($prohibited[$defaultuserroleid])) {
$nobody = true;
} else if (!empty($neded[$defaultuserroleid])) {
// everybody not having prohibit has the capability
$needed = array();
} else if (empty($needed)) {
$nobody = true;
}
}
}
if ($nobody) {
// nobody can match so return some SQL that does not return any results
return array("SELECT {$prefix}.id FROM {user} {$prefix} WHERE 1=2", array());
}
$joins = array();
$params = array();
$wheres = array("{$prefix}.deleted = 0 AND {$prefix}.username <> 'guest'");
if ($courseneeded) {
$ctxids = implode(',', $coursecontextids);
$roleids = implode(',', array_keys($courseneeded));
$joins[] = "JOIN {role_assignments} {$prefix}_ra1 ON ({$prefix}_ra1.userid = {$prefix}.id AND {$prefix}_ra1.roleid IN ($roleids) AND {$prefix}_ra1.contextid IN ($ctxids))";
}
if ($courseprohibited) {
$ctxids = implode(',', $coursecontextids);
$roleids = implode(',', array_keys($courseprohibited));
$joins[] = "LEFT JOIN {role_assignments} {$prefix}_ra2 ON ({$prefix}_ra2.userid = {$prefix}.id AND {$prefix}_ra2.roleid IN ($roleids) AND {$prefix}_ra2.contextid IN ($ctxids))";
$wheres[] = "{$prefix}_ra2 IS NULL";
}
if ($needed) {
$ctxids = implode(',', $contextids);
$roleids = implode(',', array_keys($needed));
$joins[] = "JOIN {role_assignments} {$prefix}_ra3 ON ({$prefix}_ra3.userid = {$prefix}.id AND {$prefix}_ra3.roleid IN ($roleids) AND {$prefix}_ra3.contextid IN ($ctxids))";
}
if ($prohibited) {
$ctxids = implode(',', $contextids);
$roleids = implode(',', array_keys($prohibited));
$joins[] = "LEFT JOIN {role_assignments} {$prefix}_ra4 ON ({$prefix}_ra4.userid = {$prefix}.id AND {$prefix}_ra4.roleid IN ($roleids) AND {$prefix}_ra4.contextid IN ($ctxids))";
$wheres[] = "{$prefix}_ra4 IS NULL";
}
if ($groupid) {
$joins[] = "JOIN {groups_members} {$prefix}gm ON ({$prefix}gm.userid = {$prefix}.id AND {$prefix}.roleid = :{$prefix}gmid)";
$params["{$prefix}gmid"] = $groupid;
}
$joins = implode("\n", $joins);
$wheres = "WHERE ".implode(" AND ", $wheres);
$sql = "SELECT DISTINCT {$prefix}.id
FROM {user} {$prefix}
$joins
$wheres";
return array($sql, $params);
}
/**
* Returns list of users enrolled into course.
* @param object $context
* @param string $withcapability
* @param int $groupid 0 means ignore groups, any other value limits the result by group id
* @param string $userfields requested user record fields
* @param string $orderby
* @param int $limitfrom return a subset of records, starting at this point (optional, required if $limitnum is set).
* @param int $limitnum return a subset comprising this many records (optional, required if $limitfrom is set).
* @return array of user records
*/
function get_enrolled_users($context, $withcapability = '', $groupid = 0, $userfields = 'u.*', $orderby = '', $limitfrom = 0, $limitnum = 0) {
global $DB;
list($esql, $params) = get_enrolled_sql($context, $withcapability, $groupid);
$sql = "SELECT $userfields
FROM {user} u
JOIN ($esql) je ON je.id = u.id
WHERE u.deleted = 0";
if ($orderby) {
$sql = "$sql ORDER BY $orderby";
} else {
$sql = "$sql ORDER BY u.lastname ASC, u.firstname ASC";
}
return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
}
/**
* Counts list of users enrolled into course (as per above function)
* @param object $context
* @param string $withcapability
* @param int $groupid 0 means ignore groups, any other value limits the result by group id
* @return array of user records
*/
function count_enrolled_users($context, $withcapability = '', $groupid = 0) {
global $DB;
list($esql, $params) = get_enrolled_sql($context, $withcapability, $groupid);
$sql = "SELECT count(u.id)
FROM {user} u
JOIN ($esql) je ON je.id = u.id
WHERE u.deleted = 0";
return $DB->count_records_sql($sql, $params);
}
/**
* Loads the capability definitions for the component (from file).
*
* Loads the capability definitions for the component (from file). If no
* capabilities are defined for the component, we simply return an empty array.
*
* @global object
* @param string $component full plugin name, examples: 'moodle', 'mod_forum'
* @return array array of capabilities
*/
function load_capability_def($component) {
$defpath = get_component_directory($component).'/db/access.php';
$capabilities = array();
if (file_exists($defpath)) {
require($defpath);
if (!empty(${$component.'_capabilities'})) {
// BC capability array name
// since 2.0 we prefer $capabilities instead - it is easier to use and matches db/* files
debugging('componentname_capabilities array is deprecated, please use capabilities array only in access.php files');
$capabilities = ${$component.'_capabilities'};
}
}
return $capabilities;
}
/**
* Gets the capabilities that have been cached in the database for this component.
* @param string $component - examples: 'moodle', 'mod_forum'
* @return array array of capabilities
*/
function get_cached_capabilities($component='moodle') {
global $DB;
return $DB->get_records('capabilities', array('component'=>$component));
}
/**
* Returns default capabilities for given role archetype.
* @param string $archetype role archetype
* @return array
*/
function get_default_capabilities($archetype) {
global $DB;
if (!$archetype) {
return array();
}
$alldefs = array();
$defaults = array();
$components = array();
$allcaps = $DB->get_records('capabilities');
foreach ($allcaps as $cap) {
if (!in_array($cap->component, $components)) {
$components[] = $cap->component;
$alldefs = array_merge($alldefs, load_capability_def($cap->component));
}
}
foreach($alldefs as $name=>$def) {
if (isset($def['legacy'][$archetype])) {
$defaults[$name] = $def['legacy'][$archetype];
}
}
return $defaults;
}
/**
* Reset role capabilitites to default according to selected role archetype.
* If no archetype selected, removes all capabilities.
* @param int @roleid
*/
function reset_role_capabilities($roleid) {
global $DB;
$role = $DB->get_record('role', array('id'=>$roleid), '*', MUST_EXIST);
$defaultcaps = get_default_capabilities($role->archetype);
$sitecontext = get_context_instance(CONTEXT_SYSTEM);
$DB->delete_records('role_capabilities', array('roleid'=>$roleid));
foreach($defaultcaps as $cap=>$permission) {
assign_capability($cap, $permission, $roleid, $sitecontext->id);
}
}
/**
* Updates the capabilities table with the component capability definitions.
* If no parameters are given, the function updates the core moodle
* capabilities.
*
* Note that the absence of the db/access.php capabilities definition file
* will cause any stored capabilities for the component to be removed from
* the database.
*
* @global object
* @param string $component examples: 'moodle', 'mod/forum', 'block/quiz_results'
* @return boolean true if success, exception in case of any problems
*/
function update_capabilities($component='moodle') {
global $DB, $OUTPUT;
$storedcaps = array();
$filecaps = load_capability_def($component);
$cachedcaps = get_cached_capabilities($component);
if ($cachedcaps) {
foreach ($cachedcaps as $cachedcap) {
array_push($storedcaps, $cachedcap->name);
// update risk bitmasks and context levels in existing capabilities if needed
if (array_key_exists($cachedcap->name, $filecaps)) {
if (!array_key_exists('riskbitmask', $filecaps[$cachedcap->name])) {
$filecaps[$cachedcap->name]['riskbitmask'] = 0; // no risk if not specified
}
if ($cachedcap->captype != $filecaps[$cachedcap->name]['captype']) {
$updatecap = new object();
$updatecap->id = $cachedcap->id;
$updatecap->captype = $filecaps[$cachedcap->name]['captype'];
$DB->update_record('capabilities', $updatecap);
}
if ($cachedcap->riskbitmask != $filecaps[$cachedcap->name]['riskbitmask']) {
$updatecap = new object();
$updatecap->id = $cachedcap->id;
$updatecap->riskbitmask = $filecaps[$cachedcap->name]['riskbitmask'];
$DB->update_record('capabilities', $updatecap);
}
if (!array_key_exists('contextlevel', $filecaps[$cachedcap->name])) {
$filecaps[$cachedcap->name]['contextlevel'] = 0; // no context level defined
}
if ($cachedcap->contextlevel != $filecaps[$cachedcap->name]['contextlevel']) {
$updatecap = new object();
$updatecap->id = $cachedcap->id;
$updatecap->contextlevel = $filecaps[$cachedcap->name]['contextlevel'];
$DB->update_record('capabilities', $updatecap);
}
}
}
}
// Are there new capabilities in the file definition?
$newcaps = array();
foreach ($filecaps as $filecap => $def) {
if (!$storedcaps ||
($storedcaps && in_array($filecap, $storedcaps) === false)) {
if (!array_key_exists('riskbitmask', $def)) {
$def['riskbitmask'] = 0; // no risk if not specified
}
$newcaps[$filecap] = $def;
}
}
// Add new capabilities to the stored definition.
foreach ($newcaps as $capname => $capdef) {
$capability = new object();
$capability->name = $capname;
$capability->captype = $capdef['captype'];
$capability->contextlevel = $capdef['contextlevel'];
$capability->component = $component;
$capability->riskbitmask = $capdef['riskbitmask'];
$DB->insert_record('capabilities', $capability, false);
if (isset($capdef['clonepermissionsfrom']) && in_array($capdef['clonepermissionsfrom'], $storedcaps)){
if ($rolecapabilities = $DB->get_records('role_capabilities', array('capability'=>$capdef['clonepermissionsfrom']))){
foreach ($rolecapabilities as $rolecapability){
//assign_capability will update rather than insert if capability exists
if (!assign_capability($capname, $rolecapability->permission,
$rolecapability->roleid, $rolecapability->contextid, true)){
echo $OUTPUT->notification('Could not clone capabilities for '.$capname);
}
}
}
// we ignore legacy key if we have cloned permissions
} else if (isset($capdef['legacy']) && is_array($capdef['legacy'])) {
assign_legacy_capabilities($capname, $capdef['legacy']);
}
}
// Are there any capabilities that have been removed from the file
// definition that we need to delete from the stored capabilities and
// role assignments?
capabilities_cleanup($component, $filecaps);
// reset static caches
$ACCESSLIB_PRIVATE->capabilities = NULL;
return true;
}
/**
* Deletes cached capabilities that are no longer needed by the component.
* Also unassigns these capabilities from any roles that have them.
*
* @global object
* @param string $component examples: 'moodle', 'mod/forum', 'block/quiz_results'
* @param array $newcapdef array of the new capability definitions that will be
* compared with the cached capabilities
* @return int number of deprecated capabilities that have been removed
*/
function capabilities_cleanup($component, $newcapdef=NULL) {
global $DB;
$removedcount = 0;
if ($cachedcaps = get_cached_capabilities($component)) {
foreach ($cachedcaps as $cachedcap) {
if (empty($newcapdef) ||
array_key_exists($cachedcap->name, $newcapdef) === false) {
// Remove from capabilities cache.
$DB->delete_records('capabilities', array('name'=>$cachedcap->name));
$removedcount++;
// Delete from roles.
if ($roles = get_roles_with_capability($cachedcap->name)) {
foreach($roles as $role) {
if (!unassign_capability($cachedcap->name, $role->id)) {
print_error('cannotunassigncap', 'error', '', (object)array('cap'=>$cachedcap->name, 'role'=>$role->name));
}
}
}
} // End if.
}
}
return $removedcount;
}
//////////////////
// UI FUNCTIONS //
//////////////////
/**
* @param integer $contextlevel $context->context level. One of the CONTEXT_... constants.
* @return string the name for this type of context.
*/
function get_contextlevel_name($contextlevel) {
static $strcontextlevels = NULL;
if (is_null($strcontextlevels)) {
$strcontextlevels = array(
CONTEXT_SYSTEM => get_string('coresystem'),
CONTEXT_USER => get_string('user'),
CONTEXT_COURSECAT => get_string('category'),
CONTEXT_COURSE => get_string('course'),
CONTEXT_MODULE => get_string('activitymodule'),
CONTEXT_BLOCK => get_string('block')
);
}
return $strcontextlevels[$contextlevel];
}
/**
* Prints human readable context identifier.
*
* @global object
* @param object $context the context.
* @param boolean $withprefix whether to prefix the name of the context with the
* type of context, e.g. User, Course, Forum, etc.
* @param boolean $short whether to user the short name of the thing. Only applies
* to course contexts
* @return string the human readable context name.
*/
function print_context_name($context, $withprefix = true, $short = false) {
global $DB;
$name = '';
switch ($context->contextlevel) {
case CONTEXT_SYSTEM:
$name = get_string('coresystem');
break;
case CONTEXT_USER:
if ($user = $DB->get_record('user', array('id'=>$context->instanceid))) {
if ($withprefix){
$name = get_string('user').': ';
}
$name .= fullname($user);
}
break;
case CONTEXT_COURSECAT:
if ($category = $DB->get_record('course_categories', array('id'=>$context->instanceid))) {
if ($withprefix){
$name = get_string('category').': ';
}
$name .=format_string($category->name);
}
break;
case CONTEXT_COURSE:
if ($context->instanceid == SITEID) {
$name = get_string('frontpage', 'admin');
} else {
if ($course = $DB->get_record('course', array('id'=>$context->instanceid))) {
if ($withprefix){
$name = get_string('course').': ';
}
if ($short){
$name .= format_string($course->shortname);
} else {
$name .= format_string($course->fullname);
}
}
}
break;
case CONTEXT_MODULE:
if ($cm = $DB->get_record_sql('SELECT cm.*, md.name AS modname FROM {course_modules} cm ' .
'JOIN {modules} md ON md.id = cm.module WHERE cm.id = ?', array($context->instanceid))) {
if ($mod = $DB->get_record($cm->modname, array('id' => $cm->instance))) {
if ($withprefix){
$name = get_string('modulename', $cm->modname).': ';
}
$name .= $mod->name;
}
}
break;
case CONTEXT_BLOCK:
if ($blockinstance = $DB->get_record('block_instances', array('id'=>$context->instanceid))) {
global $CFG;
require_once("$CFG->dirroot/blocks/moodleblock.class.php");
require_once("$CFG->dirroot/blocks/$blockinstance->blockname/block_$blockinstance->blockname.php");
$blockname = "block_$blockinstance->blockname";
if ($blockobject = new $blockname()) {
if ($withprefix){
$name = get_string('block').': ';
}
$name .= $blockobject->title;
}
}
break;
default:
print_error('unknowncontext');
return false;
}
return $name;
}
/**
* Get a URL for a context, if there is a natural one. For example, for
* CONTEXT_COURSE, this is the course page. For CONTEXT_USER it is the
* user profile page.
*
* @param object $context the context.
* @return moodle_url
*/
function get_context_url($context) {
global $COURSE, $DB;
switch ($context->contextlevel) {
case CONTEXT_USER:
if ($COURSE->id == SITEID) {
$url = new moodle_url('/user/profile.php', array('id'=>$context->instanceid));
} else {
$url = new moodle_url('/user/view.php', array('id'=>$context->instanceid, 'courseid'=>$COURSE->id));
}
return $url;;
case CONTEXT_COURSECAT: // Coursecat -> coursecat or site
return new moodle_url('/course/category.php', array('id'=>$context->instanceid));
case CONTEXT_COURSE: // 1 to 1 to course cat
if ($context->instanceid != SITEID) {
return new moodle_url('/course/view.php', array('id'=>$context->instanceid));
}
break;
case CONTEXT_MODULE: // 1 to 1 to course
if ($modname = $DB->get_field_sql('SELECT md.name AS modname FROM {course_modules} cm ' .
'JOIN {modules} md ON md.id = cm.module WHERE cm.id = ?', array($context->instanceid))) {
return new moodle_url('/mod/' . $modname . '/view.php', array('id'=>$context->instanceid));
}
break;
case CONTEXT_BLOCK:
$parentcontexts = get_parent_contexts($context, false);
$parent = reset($parentcontexts);
$parent = get_context_instance_by_id($parent);
return get_context_url($parent);
}
return new moodle_url('/');
}
/**
* Returns an array of all the known types of risk
* The array keys can be used, for example as CSS class names, or in calls to
* print_risk_icon. The values are the corresponding RISK_ constants.
*
* @return array all the known types of risk.
*/
function get_all_risks() {
return array(
'riskmanagetrust' => RISK_MANAGETRUST,
'riskconfig' => RISK_CONFIG,
'riskxss' => RISK_XSS,
'riskpersonal' => RISK_PERSONAL,
'riskspam' => RISK_SPAM,
'riskdataloss' => RISK_DATALOSS,
);
}
/**
* Return a link to moodle docs for a given capability name
*
* @global object
* @param object $capability a capability - a row from the mdl_capabilities table.
* @return string the human-readable capability name as a link to Moodle Docs.
*/
function get_capability_docs_link($capability) {
global $CFG;
$url = get_docs_url('Capabilities/' . $capability->name);
return '<a onclick="this.target=\'docspopup\'" href="' . $url . '">' . get_capability_string($capability->name) . '</a>';
}
/**
* Extracts the relevant capabilities given a contextid.
* All case based, example an instance of forum context.
* Will fetch all forum related capabilities, while course contexts
* Will fetch all capabilities
*
* capabilities
* `name` varchar(150) NOT NULL,
* `captype` varchar(50) NOT NULL,
* `contextlevel` int(10) NOT NULL,
* `component` varchar(100) NOT NULL,
*
* @global object
* @global object
* @param object context
* @return array
*/
function fetch_context_capabilities($context) {
global $DB, $CFG;
$sort = 'ORDER BY contextlevel,component,name'; // To group them sensibly for display
$params = array();
switch ($context->contextlevel) {
case CONTEXT_SYSTEM: // all
$SQL = "SELECT *
FROM {capabilities}";
break;
case CONTEXT_USER:
$extracaps = array('moodle/grade:viewall');
list($extra, $params) = $DB->get_in_or_equal($extracaps, SQL_PARAMS_NAMED, 'cap0');
$SQL = "SELECT *
FROM {capabilities}
WHERE contextlevel = ".CONTEXT_USER."
OR name $extra";
break;
case CONTEXT_COURSECAT: // course category context and bellow
$SQL = "SELECT *
FROM {capabilities}
WHERE contextlevel IN (".CONTEXT_COURSECAT.",".CONTEXT_COURSE.",".CONTEXT_MODULE.",".CONTEXT_BLOCK.")";
break;
case CONTEXT_COURSE: // course context and bellow
$SQL = "SELECT *
FROM {capabilities}
WHERE contextlevel IN (".CONTEXT_COURSE.",".CONTEXT_MODULE.",".CONTEXT_BLOCK.")";
break;
case CONTEXT_MODULE: // mod caps
$cm = $DB->get_record('course_modules', array('id'=>$context->instanceid));
$module = $DB->get_record('modules', array('id'=>$cm->module));
$modfile = "$CFG->dirroot/mod/$module->name/lib.php";
if (file_exists($modfile)) {
include_once($modfile);
$modfunction = $module->name.'_get_extra_capabilities';
if (function_exists($modfunction)) {
$extracaps = $modfunction();
}
}
if(empty($extracaps)) {
$extracaps = array();
}
// All modules allow viewhiddenactivities. This is so you can hide
// the module then override to allow specific roles to see it.
// The actual check is in course page so not module-specific
$extracaps[]="moodle/course:viewhiddenactivities";
list($extra, $params) = $DB->get_in_or_equal(
$extracaps, SQL_PARAMS_NAMED, 'cap0');
$extra = "OR name $extra";
$SQL = "SELECT *
FROM {capabilities}
WHERE (contextlevel = ".CONTEXT_MODULE."
AND component = :component)
$extra";
$params['component'] = "mod_$module->name";
break;
case CONTEXT_BLOCK: // block caps
$bi = $DB->get_record('block_instances', array('id' => $context->instanceid));
$extra = '';
$extracaps = block_method_result($bi->blockname, 'get_extra_capabilities');
if ($extracaps) {
list($extra, $params) = $DB->get_in_or_equal($extracaps, SQL_PARAMS_NAMED, 'cap0');
$extra = "OR name $extra";
}
$SQL = "SELECT *
FROM {capabilities}
WHERE (contextlevel = ".CONTEXT_BLOCK."
AND component = :component)
$extra";
$params['component'] = 'block_' . $bi->blockname;
break;
default:
return false;
}
if (!$records = $DB->get_records_sql($SQL.' '.$sort, $params)) {
$records = array();
}
return $records;
}
/**
* This function pulls out all the resolved capabilities (overrides and
* defaults) of a role used in capability overrides in contexts at a given
* context.
*
* @global object
* @param obj $context
* @param int $roleid
* @param string $cap capability, optional, defaults to ''
* @param bool if set to true, resolve till this level, else stop at immediate parent level
* @return array
*/
function role_context_capabilities($roleid, $context, $cap='') {
global $DB;
$contexts = get_parent_contexts($context);
$contexts[] = $context->id;
$contexts = '('.implode(',', $contexts).')';
$params = array($roleid);
if ($cap) {
$search = " AND rc.capability = ? ";
$params[] = $cap;
} else {
$search = '';
}
$sql = "SELECT rc.*
FROM {role_capabilities} rc, {context} c
WHERE rc.contextid in $contexts
AND rc.roleid = ?
AND rc.contextid = c.id $search
ORDER BY c.contextlevel DESC, rc.capability DESC";
$capabilities = array();
if ($records = $DB->get_records_sql($sql, $params)) {
// We are traversing via reverse order.
foreach ($records as $record) {
// If not set yet (i.e. inherit or not set at all), or currently we have a prohibit
if (!isset($capabilities[$record->capability]) || $record->permission<-500) {
$capabilities[$record->capability] = $record->permission;
}
}
}
return $capabilities;
}
/**
* Recursive function which, given a context, find all parent context ids,
* and return the array in reverse order, i.e. parent first, then grand
* parent, etc.
*
* @param object $context
* @param bool $capability optional, defaults to false
* @return array
*/
function get_parent_contexts($context, $includeself = false) {
if ($context->path == '') {
return array();
}
$parentcontexts = substr($context->path, 1); // kill leading slash
$parentcontexts = explode('/', $parentcontexts);
if (!$includeself) {
array_pop($parentcontexts); // and remove its own id
}
return array_reverse($parentcontexts);
}
/**
* Return the id of the parent of this context, or false if there is no parent (only happens if this
* is the site context.)
*
* @param object $context
* @return integer the id of the parent context.
*/
function get_parent_contextid($context) {
$parentcontexts = get_parent_contexts($context);
if (count($parentcontexts) == 0) {
return false;
}
return array_shift($parentcontexts);
}
/**
* Constructs array with contextids as first parameter and context paths,
* in both cases bottom top including self.
*
* @param object $context
* @return array
*/
function get_context_info_list($context) {
$contextids = explode('/', ltrim($context->path, '/'));
$contextpaths = array();
$contextids2 = $contextids;
while ($contextids2) {
$contextpaths[] = '/' . implode('/', $contextids2);
array_pop($contextids2);
}
return array($contextids, $contextpaths);
}
/**
* Find course context
* @param object $context - course or lower context
* @return object context of the enclosing course, throws exception when related course context can not be found
*/
function get_course_context($context) {
if (empty($context->contextlevel)) {
throw coding_exception('Invalid context parameter.');
} if ($context->contextlevel == CONTEXT_COURSE) {
return $context;
} else if ($context->contextlevel == CONTEXT_MODULE) {
return get_context_instance_by_id(get_parent_contextid($context, MUST_EXIST));
} else if ($context->contextlevel == CONTEXT_BLOCK) {
$parentcontext = get_context_instance_by_id(get_parent_contextid($context, MUST_EXIST));
if ($parentcontext->contextlevel == CONTEXT_COURSE) {
return $parentcontext;
} else if ($parentcontext->contextlevel == CONTEXT_MODULE) {
return get_context_instance_by_id(get_parent_contextid($parentcontext, MUST_EXIST));
} else {
throw new coding_exception('Invalid level of block context parameter.');
}
}
throw new coding_exception('Invalid context level of parameter.');
}
/**
* Check if contect is the front page context or a context inside it
*
* Returns true if this context is the front page context, or a context inside it,
* otherwise false.
*
* @param object $context a context object.
* @return bool
*/
function is_inside_frontpage($context) {
$frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
return strpos($context->path . '/', $frontpagecontext->path . '/') === 0;
}
/**
* Runs get_records select on context table and returns the result
* Does get_records_select on the context table, and returns the results ordered
* by contextlevel, and then the natural sort order within each level.
* for the purpose of $select, you need to know that the context table has been
* aliased to ctx, so for example, you can call get_sorted_contexts('ctx.depth = 3');
*
* @global object
* @param string $select the contents of the WHERE clause. Remember to do ctx.fieldname.
* @param array $params any parameters required by $select.
* @return array the requested context records.
*/
function get_sorted_contexts($select, $params = array()) {
global $DB;
if ($select) {
$select = 'WHERE ' . $select;
}
return $DB->get_records_sql("
SELECT ctx.*
FROM {context} ctx
LEFT JOIN {user} u ON ctx.contextlevel = " . CONTEXT_USER . " AND u.id = ctx.instanceid
LEFT JOIN {course_categories} cat ON ctx.contextlevel = " . CONTEXT_COURSECAT . " AND cat.id = ctx.instanceid
LEFT JOIN {course} c ON ctx.contextlevel = " . CONTEXT_COURSE . " AND c.id = ctx.instanceid
LEFT JOIN {course_modules} cm ON ctx.contextlevel = " . CONTEXT_MODULE . " AND cm.id = ctx.instanceid
LEFT JOIN {block_instances} bi ON ctx.contextlevel = " . CONTEXT_BLOCK . " AND bi.id = ctx.instanceid
$select
ORDER BY ctx.contextlevel, bi.defaultregion, COALESCE(cat.sortorder, c.sortorder, cm.section, bi.defaultweight), u.lastname, u.firstname, cm.id
", $params);
}
/**
* Recursive function which, given a context, find all its children context ids.
*
* When called for a course context, it will return the modules and blocks
* displayed in the course page.
*
* For course category contexts it will return categories and courses. It will
* NOT recurse into courses, nor return blocks on the category pages. If you
* want to do that, call it on the returned courses.
*
* If called on a course context it _will_ populate the cache with the appropriate
* contexts ;-)
*
* @param object $context.
* @return array Array of child records
*/
function get_child_contexts($context) {
global $DB, $ACCESSLIB_PRIVATE;
// We *MUST* populate the context_cache as the callers
// will probably ask for the full record anyway soon after
// soon after calling us ;-)
$array = array();
switch ($context->contextlevel) {
case CONTEXT_BLOCK:
// No children.
break;
case CONTEXT_MODULE:
// Find
// - blocks under this context path.
$sql = " SELECT ctx.*
FROM {context} ctx
WHERE ctx.path LIKE ?
AND ctx.contextlevel = ".CONTEXT_BLOCK;
$params = array("{$context->path}/%", $context->instanceid);
$records = $DB->get_recordset_sql($sql, $params);
foreach ($records as $rec) {
cache_context($rec);
$array[$rec->id] = $rec;
}
break;
case CONTEXT_COURSE:
// Find
// - modules and blocks under this context path.
$sql = " SELECT ctx.*
FROM {context} ctx
WHERE ctx.path LIKE ?
AND ctx.contextlevel IN (".CONTEXT_MODULE.",".CONTEXT_BLOCK.")";
$params = array("{$context->path}/%", $context->instanceid);
$records = $DB->get_recordset_sql($sql, $params);
foreach ($records as $rec) {
cache_context($rec);
$array[$rec->id] = $rec;
}
break;
case CONTEXT_COURSECAT:
// Find
// - categories
// - courses
$sql = " SELECT ctx.*
FROM {context} ctx
WHERE ctx.path LIKE ?
AND ctx.contextlevel IN (".CONTEXT_COURSECAT.",".CONTEXT_COURSE.")";
$params = array("{$context->path}/%");
$records = $DB->get_recordset_sql($sql, $params);
foreach ($records as $rec) {
cache_context($rec);
$array[$rec->id] = $rec;
}
break;
case CONTEXT_USER:
// Find
// - blocks under this context path.
$sql = " SELECT ctx.*
FROM {context} ctx
WHERE ctx.path LIKE ?
AND ctx.contextlevel = ".CONTEXT_BLOCK;
$params = array("{$context->path}/%", $context->instanceid);
$records = $DB->get_recordset_sql($sql, $params);
foreach ($records as $rec) {
cache_context($rec);
$array[$rec->id] = $rec;
}
break;
case CONTEXT_SYSTEM:
// Just get all the contexts except for CONTEXT_SYSTEM level
// and hope we don't OOM in the process - don't cache
$sql = "SELECT c.*
FROM {context} c
WHERE contextlevel != ".CONTEXT_SYSTEM;
$records = $DB->get_records_sql($sql);
foreach ($records as $rec) {
$array[$rec->id] = $rec;
}
break;
default:
print_error('unknowcontext', '', '', $context->contextlevel);
return false;
}
return $array;
}
/**
* Gets a string for sql calls, searching for stuff in this context or above
*
* @param object $context
* @return string
*/
function get_related_contexts_string($context) {
if ($parents = get_parent_contexts($context)) {
return (' IN ('.$context->id.','.implode(',', $parents).')');
} else {
return (' ='.$context->id);
}
}
/**
* Returns capability information (cached)
*
* @param string $capabilityname
* @return object or NULL if capability not found
*/
function get_capability_info($capabilityname) {
global $ACCESSLIB_PRIVATE, $DB; // one request per page only
// TODO: cache this in shared memory if available, use new $CFG->roledefrev for version check
if (empty($ACCESSLIB_PRIVATE->capabilities)) {
$ACCESSLIB_PRIVATE->capabilities = array();
$caps = $DB->get_records('capabilities', array(), 'id, name, captype, riskbitmask');
foreach ($caps as $cap) {
$capname = $cap->name;
unset($cap->id);
unset($cap->name);
$ACCESSLIB_PRIVATE->capabilities[$capname] = $cap;
}
}
return isset($ACCESSLIB_PRIVATE->capabilities[$capabilityname]) ? $ACCESSLIB_PRIVATE->capabilities[$capabilityname] : NULL;
}
/**
* Returns the human-readable, translated version of the capability.
* Basically a big switch statement.
*
* @param string $capabilityname e.g. mod/choice:readresponses
* @return string
*/
function get_capability_string($capabilityname) {
// Typical capabilityname is mod/choice:readresponses
$names = split('/', $capabilityname);
$stringname = $names[1]; // choice:readresponses
$components = split(':', $stringname);
$componentname = $components[0]; // choice
switch ($names[0]) {
case 'report':
$string = get_string($stringname, 'report_'.$componentname);
break;
case 'mod':
$string = get_string($stringname, $componentname);
break;
case 'block':
$string = get_string($stringname, 'block_'.$componentname);
break;
case 'moodle':
if ($componentname == 'local') {
$string = get_string($stringname, 'local');
} else {
$string = get_string($stringname, 'role');
}
break;
case 'enrol':
$string = get_string($stringname, 'enrol_'.$componentname);
break;
case 'format':
$string = get_string($stringname, 'format_'.$componentname);
break;
case 'format':
$string = get_string($stringname, 'editor_'.$componentname);
break;
case 'gradeexport':
$string = get_string($stringname, 'gradeexport_'.$componentname);
break;
case 'gradeimport':
$string = get_string($stringname, 'gradeimport_'.$componentname);
break;
case 'gradereport':
$string = get_string($stringname, 'gradereport_'.$componentname);
break;
case 'coursereport':
$string = get_string($stringname, 'coursereport_'.$componentname);
break;
case 'quizreport':
$string = get_string($stringname, 'quiz_'.$componentname);
break;
case 'repository':
$string = get_string($stringname, 'repository_'.$componentname);
break;
case 'local':
$string = get_string($stringname, 'local_'.$componentname);
break;
case 'webservice':
$string = get_string($stringname, 'webservice_'.$componentname);
break;
default:
$string = get_string($stringname);
break;
}
return $string;
}
/**
* This gets the mod/block/course/core etc strings.
*
* @param string $component
* @param int $contextlevel
* @return string|bool String is success, false if failed
*/
function get_component_string($component, $contextlevel) {
switch ($contextlevel) {
case CONTEXT_SYSTEM:
if (preg_match('|^enrol|', $component)) {
$langname = str_replace('/', '_', $component);
$string = get_string('enrolname', $langname);
} else if (preg_match('|^block|', $component)) {
$langname = str_replace('/', '_', $component);
$string = get_string('pluginname', $langname);
} else if (preg_match('|^local|', $component)) {
$langname = str_replace('/', '_', $component);
$string = get_string('local');
} else if (preg_match('|^repository|', $component)) {
$string = get_string('repository', 'repository').': '.get_string('repositoryname', $component);
} else if (preg_match('|^report|', $component)) {
$string = get_string('reports');
} else {
$string = get_string('coresystem');
}
break;
case CONTEXT_USER:
$string = get_string('users');
break;
case CONTEXT_COURSECAT:
$string = get_string('categories');
break;
case CONTEXT_COURSE:
if (preg_match('|^gradeimport|', $component)) {
$string = get_string('gradeimport', 'grades').': '.get_string('modulename', $component);
} else if (preg_match('|^gradeexport|', $component)) {
$string = get_string('gradeexport', 'grades').': '.get_string('modulename', $component);
} else if (preg_match('|^gradereport|', $component)) {
$string = get_string('gradereport', 'grades').': '.get_string('modulename', $component);
} else if (preg_match('|^coursereport|', $component)) {
$string = get_string('coursereport').': '.get_string('pluginname', $component);
} else if (preg_match('|^webservice|', $component)) {
$string = get_string('webservice', 'webservice').': '.get_string('pluginname', $component);
} else {
$string = get_string('course');
}
break;
case CONTEXT_MODULE:
if (preg_match('|^quiz_([a-z_]*)|', $component, $matches)){
$langname = 'quiz_'.$matches[1];
$string = get_string($matches[1].':componentname', $langname);
} else if (preg_match('|^moodle|', $component)) {
$string = get_string('coresystem');
} else {
$string = get_string('activity').': '.get_string('modulename', preg_replace('#(\w+_)#', '', basename($component)));
}
break;
case CONTEXT_BLOCK:
if ($component == 'moodle' ){
$string = get_string('block');
}else{
$string = get_string('block').': '.get_string('pluginname', basename($component));
}
break;
default:
print_error('unknowncontext');
return false;
}
return $string;
}
/**
* Gets the list of roles assigned to this context and up (parents)
* from the list of roles that are visible on user profile page
* and participants page.
*
* @param object $context
* @return array
*/
function get_profile_roles($context) {
global $CFG, $DB;
if (empty($CFG->profileroles)) {
return array();
}
$allowed = explode(',', $CFG->profileroles);
list($rallowed, $params) = $DB->get_in_or_equal($allowed, SQL_PARAMS_NAMED);
$contextlist = get_related_contexts_string($context);
$sql = "SELECT DISTINCT r.id, r.name, r.shortname, r.sortorder
FROM {role_assignments} ra, {role} r
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
AND r.id $rallowed
ORDER BY r.sortorder ASC";
return $DB->get_records_sql($sql, $params);
}
/**
* Gets the list of roles assigned to this context and up (parents)
*
* @param object $context
* @return array
*/
function get_roles_used_in_context($context) {
global $DB;
$contextlist = get_related_contexts_string($context);
$sql = "SELECT DISTINCT r.id, r.name, r.shortname, r.sortorder
FROM {role_assignments} ra, {role} r
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
ORDER BY r.sortorder ASC";
return $DB->get_records_sql($sql);
}
/**
* This function is used to print roles column in user profile page.
* It is using the CFG->profileroles to limit the list to only interesting roles.
* (The permission tab has full details of user role assingments.)
*
* @param int $userid
* @param int $courseid
* @return string
*/
function get_user_roles_in_course($userid, $courseid) {
global $CFG, $DB,$USER;
if (empty($CFG->profileroles)) {
return '';
}
if ($courseid == SITEID) {
$context = get_context_instance(CONTEXT_SYSTEM);
} else {
$context = get_context_instance(CONTEXT_COURSE, $courseid);
}
if (empty($CFG->profileroles)) {
return array();
}
$allowed = explode(',', $CFG->profileroles);
list($rallowed, $params) = $DB->get_in_or_equal($allowed, SQL_PARAMS_NAMED);
$contextlist = get_related_contexts_string($context);
$sql = "SELECT DISTINCT r.id, r.name, r.shortname, r.sortorder
FROM {role_assignments} ra, {role} r
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
AND r.id $rallowed
AND ra.userid = :userid
ORDER BY r.sortorder ASC";
$params['userid'] = $userid;
$rolestring = '';
if ($roles = $DB->get_records_sql($sql, $params)) {
foreach ($roles as $userrole) {
$rolenames[$userrole->id] = $userrole->name;
}
$rolenames = role_fix_names($rolenames, $context); // Substitute aliases
foreach ($rolenames as $roleid => $rolename) {
$rolenames[$roleid] = '<a href="'.$CFG->wwwroot.'/user/index.php?contextid='.$context->id.'&amp;roleid='.$roleid.'">'.$rolename.'</a>';
}
$rolestring = implode(',', $rolenames);
}
return $rolestring;
}
/**
* Checks if a user can assign users to a particular role in this context
*
* @global object
* @param object $context
* @param int $targetroleid - the id of the role you want to assign users to
* @return boolean
*/
function user_can_assign($context, $targetroleid) {
global $DB;
// first check if user has override capability
// if not return false;
if (!has_capability('moodle/role:assign', $context)) {
return false;
}
// pull out all active roles of this user from this context(or above)
if ($userroles = get_user_roles($context)) {
foreach ($userroles as $userrole) {
// if any in the role_allow_override table, then it's ok
if ($DB->get_record('role_allow_assign', array('roleid'=>$userrole->roleid, 'allowassign'=>$targetroleid))) {
return true;
}
}
}
return false;
}
/**
* Returns all site roles in correct sort order.
*
* @return array
*/
function get_all_roles() {
global $DB;
return $DB->get_records('role', NULL, 'sortorder ASC');
}
/**
* Returns roles of a specified archetype
* @param string $archetype
* @return array of full role records
*/
function get_archetype_roles($archetype) {
global $DB;
return $DB->get_records('role', array('archetype'=>$archetype));
}
/**
* Gets all the user roles assigned in this context, or higher contexts
* this is mainly used when checking if a user can assign a role, or overriding a role
* i.e. we need to know what this user holds, in order to verify against allow_assign and
* allow_override tables
*
* @param object $context
* @param int $userid
* @param bool $checkparentcontexts defaults to true
* @param string $order defaults to 'c.contextlevel DESC, r.sortorder ASC'
* @return array
*/
function get_user_roles($context, $userid=0, $checkparentcontexts=true, $order='c.contextlevel DESC, r.sortorder ASC') {
global $USER, $DB;
if (empty($userid)) {
if (empty($USER->id)) {
return array();
}
$userid = $USER->id;
}
if ($checkparentcontexts) {
$contextids = get_parent_contexts($context);
} else {
$contextids = array();
}
$contextids[] = $context->id;
list($contextids, $params) = $DB->get_in_or_equal($contextids, SQL_PARAMS_QM);
array_unshift($params, $userid);
$sql = "SELECT ra.*, r.name, r.shortname
FROM {role_assignments} ra, {role} r, {context} c
WHERE ra.userid = ?
AND ra.roleid = r.id
AND ra.contextid = c.id
AND ra.contextid $contextids
ORDER BY $order";
return $DB->get_records_sql($sql ,$params);
}
/**
* Creates a record in the role_allow_override table
*
* @global object
* @param int $sroleid source roleid
* @param int $troleid target roleid
* @return int id or false
*/
function allow_override($sroleid, $troleid) {
global $DB;
$record = new object();
$record->roleid = $sroleid;
$record->allowoverride = $troleid;
$DB->insert_record('role_allow_override', $record);
}
/**
* Creates a record in the role_allow_assign table
*
* @global object
* @param int $sroleid source roleid
* @param int $troleid target roleid
* @return int id or false
*/
function allow_assign($fromroleid, $targetroleid) {
global $DB;
$record = new object();
$record->roleid = $fromroleid;
$record->allowassign = $targetroleid;
$DB->insert_record('role_allow_assign', $record);
}
/**
* Creates a record in the role_allow_switch table
*
* @global object
* @param int $sroleid source roleid
* @param int $troleid target roleid
* @return int id or false
*/
function allow_switch($fromroleid, $targetroleid) {
global $DB;
$record = new object();
$record->roleid = $fromroleid;
$record->allowswitch = $targetroleid;
$DB->insert_record('role_allow_switch', $record);
}
/**
* Gets a list of roles that this user can assign in this context
*
* @global object
* @global object
* @param object $context the context.
* @param int $rolenamedisplay the type of role name to display. One of the
* ROLENAME_X constants. Default ROLENAME_ALIAS.
* @param bool $withusercounts if true, count the number of users with each role.
* @return array if $withusercounts is false, then an array $roleid => $rolename.
* if $withusercounts is true, returns a list of three arrays,
* $rolenames, $rolecounts, and $nameswithcounts.
*/
function get_assignable_roles($context, $rolenamedisplay = ROLENAME_ALIAS, $withusercounts = false) {
global $USER, $DB;
if (!has_capability('moodle/role:assign', $context)) {
if ($withusercounts) {
return array(array(), array(), array());
} else {
return array();
}
}
$parents = get_parent_contexts($context, true);
$contexts = implode(',' , $parents);
$params = array();
$extrafields = '';
if ($rolenamedisplay == ROLENAME_ORIGINALANDSHORT) {
$extrafields .= ', r.shortname';
}
if ($withusercounts) {
$extrafields = ', (SELECT count(u.id)
FROM {role_assignments} cra JOIN {user} u ON cra.userid = u.id
WHERE cra.roleid = r.id AND cra.contextid = :conid AND u.deleted = 0
) AS usercount';
$params['conid'] = $context->id;
}
if (is_siteadmin()) {
// show all roles allowed in this context to admins
$assignrestriction = "";
} else {
$assignrestriction = "JOIN (SELECT DISTINCT raa.allowassign AS id
FROM {role_allow_assign} raa
JOIN {role_assignments} ra ON ra.roleid = raa.roleid
WHERE ra.userid = :userid AND ra.contextid IN ($contexts)
) ar ON ar.id = r.id";
$params['userid'] = $USER->id;
}
$params['contextlevel'] = $context->contextlevel;
$sql = "SELECT r.id, r.name $extrafields
FROM {role} r
$assignrestriction
JOIN {role_context_levels} rcl ON r.id = rcl.roleid
WHERE rcl.contextlevel = :contextlevel
ORDER BY r.sortorder ASC";
$roles = $DB->get_records_sql($sql, $params);
$rolenames = array();
foreach ($roles as $role) {
$rolenames[$role->id] = $role->name;
if ($rolenamedisplay == ROLENAME_ORIGINALANDSHORT) {
$rolenames[$role->id] .= ' (' . $role->shortname . ')';
}
}
if ($rolenamedisplay != ROLENAME_ORIGINALANDSHORT) {
$rolenames = role_fix_names($rolenames, $context, $rolenamedisplay);
}
if (!$withusercounts) {
return $rolenames;
}
$rolecounts = array();
$nameswithcounts = array();
foreach ($roles as $role) {
$nameswithcounts[$role->id] = $rolenames[$role->id] . ' (' . $roles[$role->id]->usercount . ')';
$rolecounts[$role->id] = $roles[$role->id]->usercount;
}
return array($rolenames, $rolecounts, $nameswithcounts);
}
/**
* Gets a list of roles that this user can switch to in a context
*
* Gets a list of roles that this user can switch to in a context, for the switchrole menu.
* This function just process the contents of the role_allow_switch table. You also need to
* test the moodle/role:switchroles to see if the user is allowed to switch in the first place.
*
* @global object
* @global object
* @param object $context a context.
* @return array an array $roleid => $rolename.
*/
function get_switchable_roles($context) {
global $USER, $DB;
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
$params = array();
$extrajoins = '';
$extrawhere = '';
if (!is_siteadmin()) {
// Admins are allowed to switch to any role with 'moodle/course:participate' in the
// role definition.
// Others are subject to the additional constraint that the switch-to role must be allowed by
// 'role_allow_switch' for some role they have assigned in this context or any parent.
$parents = get_parent_contexts($context);
$parents[] = $context->id;
$contexts = implode(',' , $parents);
$extrajoins = "JOIN {role_allow_switch} ras ON ras.allowswitch = rc.roleid
JOIN {role_assignments} ra ON ra.roleid = ras.roleid";
$extrawhere = "AND ra.userid = :userid AND ra.contextid IN ($contexts)";
$params['userid'] = $USER->id;
}
$query = "
SELECT r.id, r.name
FROM (
SELECT DISTINCT rc.roleid
FROM {role_capabilities} rc
$extrajoins
WHERE rc.capability = :viewcap
AND rc.permission = " . CAP_ALLOW . "
AND rc.contextid = :syscontextid
$extrawhere
) idlist
JOIN {role} r ON r.id = idlist.roleid
ORDER BY r.sortorder";
$params['syscontextid'] = $systemcontext->id;
$params['viewcap'] = 'moodle/course:participate';
$rolenames = $DB->get_records_sql_menu($query, $params);
return role_fix_names($rolenames, $context, ROLENAME_ALIAS);
}
/**
* Get an array of role ids that might possibly be the target of a switchrole.
* Our policy is that you cannot switch to admin role
* and you can only switch to a role with moodle/course:participate. This method returns
* a list of those role ids.
*
* @global object
* @return array an array whose keys are the allowed role ids.
*/
function get_allowed_switchable_roles() {
global $CFG, $DB;
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
$query = "
SELECT DISTINCT rc.roleid, 1
FROM {role_capabilities} rc
JOIN {role} r ON r.id = rc.roleid
WHERE rc.capability = :participate
AND rc.permission = " . CAP_ALLOW . "
AND rc.contextid = :syscontextid";
$params = array('syscontextid' => $systemcontext->id, 'participate' => 'moodle/course:participate');
return $DB->get_records_sql_menu($query, $params);
}
/**
* Gets a list of roles that this user can override in this context.
*
* @global object
* @global object
* @param object $context the context.
* @param int $rolenamedisplay the type of role name to display. One of the
* ROLENAME_X constants. Default ROLENAME_ALIAS.
* @param bool $withcounts if true, count the number of overrides that are set for each role.
* @return array if $withcounts is false, then an array $roleid => $rolename.
* if $withusercounts is true, returns a list of three arrays,
* $rolenames, $rolecounts, and $nameswithcounts.
*/
function get_overridable_roles($context, $rolenamedisplay = ROLENAME_ALIAS, $withcounts = false) {
global $USER, $DB;
if (!has_any_capability(array('moodle/role:safeoverride', 'moodle/role:override'), $context)) {
if ($withcounts) {
return array(array(), array(), array());
} else {
return array();
}
}
$parents = get_parent_contexts($context);
$parents[] = $context->id;
$contexts = implode(',' , $parents);
$params = array();
$extrafields = '';
if ($rolenamedisplay == ROLENAME_ORIGINALANDSHORT) {
$extrafields .= ', ro.shortname';
}
$params['userid'] = $USER->id;
if ($withcounts) {
$extrafields = ', (SELECT count(rc.id) FROM {role_capabilities} rc
WHERE rc.roleid = ro.id AND rc.contextid = :conid) AS overridecount';
$params['conid'] = $context->id;
}
if (is_siteadmin()) {
// show all roles to admins
$roles = $DB->get_records_sql("
SELECT ro.id, ro.name$extrafields
FROM {role} ro
ORDER BY ro.sortorder ASC", $params);
} else {
$roles = $DB->get_records_sql("
SELECT ro.id, ro.name$extrafields
FROM {role} ro
JOIN (SELECT DISTINCT r.id
FROM {role} r
JOIN {role_allow_override} rao ON r.id = rao.allowoverride
JOIN {role_assignments} ra ON rao.roleid = ra.roleid
WHERE ra.userid = :userid AND ra.contextid IN ($contexts)
) inline_view ON ro.id = inline_view.id
ORDER BY ro.sortorder ASC", $params);
}
$rolenames = array();
foreach ($roles as $role) {
$rolenames[$role->id] = $role->name;
if ($rolenamedisplay == ROLENAME_ORIGINALANDSHORT) {
$rolenames[$role->id] .= ' (' . $role->shortname . ')';
}
}
if ($rolenamedisplay != ROLENAME_ORIGINALANDSHORT) {
$rolenames = role_fix_names($rolenames, $context, $rolenamedisplay);
}
if (!$withcounts) {
return $rolenames;
}
$rolecounts = array();
$nameswithcounts = array();
foreach ($roles as $role) {
$nameswithcounts[$role->id] = $rolenames[$role->id] . ' (' . $roles[$role->id]->overridecount . ')';
$rolecounts[$role->id] = $roles[$role->id]->overridecount;
}
return array($rolenames, $rolecounts, $nameswithcounts);
}
/**
* @global object
* @param integer $roleid the id of a role.
* @return array list of the context levels at which this role may be assigned.
*/
function get_role_contextlevels($roleid) {
global $DB;
return $DB->get_records_menu('role_context_levels', array('roleid' => $roleid),
'contextlevel', 'id,contextlevel');
}
/**
* @global object
* @param integer $contextlevel a contextlevel.
* @return array list of role ids that are assignable at this context level.
*/
function get_roles_for_contextlevels($contextlevel) {
global $DB;
return $DB->get_records_menu('role_context_levels', array('contextlevel' => $contextlevel),
'', 'id,roleid');
}
/**
* @param string $rolearchetype one of the role archetypes - that is, one of the keys
* from the array returned by get_role_archetypes();
* @return array list of the context levels at which this type of role may be assigned by default.
*/
function get_default_contextlevels($rolearchetype) {
static $defaults = array(
'manager' => array(CONTEXT_SYSTEM, CONTEXT_COURSECAT, CONTEXT_COURSE),
'coursecreator' => array(CONTEXT_SYSTEM, CONTEXT_COURSECAT),
'editingteacher' => array(CONTEXT_COURSECAT, CONTEXT_COURSE, CONTEXT_MODULE),
'teacher' => array(CONTEXT_COURSECAT, CONTEXT_COURSE, CONTEXT_MODULE),
'student' => array(CONTEXT_COURSE, CONTEXT_MODULE),
'guest' => array(),
'user' => array(),
'frontpage' => array()
);
if (isset($defaults[$rolearchetype])) {
return $defaults[$rolearchetype];
} else {
return array();
}
}
/**
* Set the context levels at which a particular role can be assigned.
* Throws exceptions in case of error.
*
* @global object
* @param integer $roleid the id of a role.
* @param array $contextlevels the context levels at which this role should be assignable.
*/
function set_role_contextlevels($roleid, array $contextlevels) {
global $DB;
$DB->delete_records('role_context_levels', array('roleid' => $roleid));
$rcl = new stdClass;
$rcl->roleid = $roleid;
foreach ($contextlevels as $level) {
$rcl->contextlevel = $level;
$DB->insert_record('role_context_levels', $rcl, false, true);
}
}
/**
* Returns a role object that is the default role for new enrolments
* in a given course
*
* @global object
* @global object
* @param object $course
* @return object returns a role or NULL if none set
*/
function get_default_course_role($course) {
global $DB, $CFG;
/// First let's take the default role the course may have
if (!empty($course->defaultrole)) {
if ($role = $DB->get_record('role', array('id'=>$course->defaultrole))) {
return $role;
}
}
/// Otherwise the site setting should tell us
if ($CFG->defaultcourseroleid) {
if ($role = $DB->get_record('role', array('id'=>$CFG->defaultcourseroleid))) {
return $role;
}
}
/// It's unlikely we'll get here, but just in case, try and find a student role
if ($studentroles = $DB->get_records('role', array('archetype'=>'student'))) {
return array_shift($studentroles); /// Take the first one
}
return NULL;
}
/**
* Who has this capability in this context?
*
* This can be a very expensive call - use sparingly and keep
* the results if you are going to need them again soon.
*
* Note if $fields is empty this function attempts to get u.*
* which can get rather large - and has a serious perf impact
* on some DBs.
*
* @param object $context
* @param string|array $capability - capability name(s)
* @param string $fields - fields to be pulled. The user table is aliased to 'u'. u.id MUST be included.
* @param string $sort - the sort order. Default is lastaccess time.
* @param mixed $limitfrom - number of records to skip (offset)
* @param mixed $limitnum - number of records to fetch
* @param string|array $groups - single group or array of groups - only return
* users who are in one of these group(s).
* @param string|array $exceptions - list of users to exclude, comma separated or array
* @param bool $doanything_ignored not used any more, admin accounts are never returned
* @param bool $view_ignored - use get_enrolled_sql() instead
* @param bool $useviewallgroups if $groups is set the return users who
* have capability both $capability and moodle/site:accessallgroups
* in this context, as well as users who have $capability and who are
* in $groups.
* @return mixed
*/
function get_users_by_capability($context, $capability, $fields='', $sort='', $limitfrom='', $limitnum='',
$groups='', $exceptions='', $doanything_ignored=NULL, $view_ignored=NULL, $useviewallgroups=false) {
global $CFG, $DB;
if (empty($context->id)) {
throw new coding_exception('Invalid context specified');
}
$defaultuserroleid = isset($CFG->defaultuserroleid) ? $CFG->defaultuserroleid : NULL;
$defaultfrontpageroleid = isset($CFG->defaultfrontpageroleid) ? $CFG->defaultfrontpageroleid : NULL;
$ctxids = trim($context->path, '/');
$ctxids = str_replace('/', ',', $ctxids);
// Context is the frontpage
$iscoursepage = false; // coursepage other than fp
$isfrontpage = false;
if ($context->contextlevel == CONTEXT_COURSE) {
if ($context->instanceid == SITEID) {
$isfrontpage = true;
} else {
$iscoursepage = true;
}
}
$isfrontpage = ($isfrontpage || is_inside_frontpage($context));
$caps = (array)$capability;
// contruct list of context paths bottom-->top
list($contextids, $paths) = get_context_info_list($context);
// we need to find out all roles that have these capabilities either in definition or in overrides
$defs = array();
list($incontexts, $params) = $DB->get_in_or_equal($contextids, SQL_PARAMS_NAMED, 'con000');
list($incaps, $params2) = $DB->get_in_or_equal($caps, SQL_PARAMS_NAMED, 'cap000');
$params = array_merge($params, $params2);
$sql = "SELECT rc.id, rc.roleid, rc.permission, rc.capability, ctx.path
FROM {role_capabilities} rc
JOIN {context} ctx on rc.contextid = ctx.id
WHERE rc.contextid $incontexts AND rc.capability $incaps";
$rcs = $DB->get_records_sql($sql, $params);
foreach ($rcs as $rc) {
$defs[$rc->capability][$rc->path][$rc->roleid] = $rc->permission;
}
// go through the permissions bottom-->top direction to evaluate the current permission,
// first one wins (prohibit is an exception that always wins)
$access = array();
foreach ($caps as $cap) {
foreach ($paths as $path) {
if (empty($defs[$cap][$path])) {
continue;
}
foreach($defs[$cap][$path] as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
$access[$cap][$roleid] = CAP_PROHIBIT;
continue;
}
if (!isset($access[$cap][$roleid])) {
$access[$cap][$roleid] = (int)$perm;
}
}
}
}
// make lists of roles that are needed and prohibited in this context
$needed = array(); // one of these is enough
$prohibited = array(); // must not have any of these
foreach ($caps as $cap) {
if (empty($access[$cap])) {
continue;
}
foreach ($access[$cap] as $roleid => $perm) {
if ($perm == CAP_PROHIBIT) {
unset($needed[$cap][$roleid]);
$prohibited[$cap][$roleid] = true;
} else if ($perm == CAP_ALLOW and empty($prohibited[$cap][$roleid])) {
$needed[$cap][$roleid] = true;
}
}
if (empty($needed[$cap]) or !empty($prohibited[$cap][$defaultuserroleid])) {
// easy, nobody has the permission
unset($needed[$cap]);
unset($prohibited[$cap]);
} else if ($isfrontpage and !empty($prohibited[$cap][$defaultfrontpageroleid])) {
// everybody is disqualified on the frontapge
unset($needed[$cap]);
unset($prohibited[$cap]);
}
if (empty($prohibited[$cap])) {
unset($prohibited[$cap]);
}
}
if (empty($needed)) {
// there can not be anybody if no roles match this request
return array();
}
if (empty($prohibited)) {
// we can compact the needed roles
$n = array();
foreach ($needed as $cap) {
foreach ($cap as $roleid=>$unused) {
$n[$roleid] = true;
}
}
$needed = array('any'=>$n);
unset($n);
}
/// ***** Set up default fields ******
if (empty($fields)) {
if ($iscoursepage) {
$fields = 'u.*, ul.timeaccess AS lastaccess';
} else {
$fields = 'u.*';
}
} else {
if (debugging('', DEBUG_DEVELOPER) && strpos($fields, 'u.*') === false && strpos($fields, 'u.id') === false) {
debugging('u.id must be included in the list of fields passed to get_users_by_capability().', DEBUG_DEVELOPER);
}
}
/// Set up default sort
if (empty($sort)) { // default to course lastaccess or just lastaccess
if ($iscoursepage) {
$sort = 'ul.timeaccess';
} else {
$sort = 'u.lastaccess';
}
}
$sortby = "ORDER BY $sort";
// Prepare query clauses
$wherecond = array();
$params = array();
$joins = array();
// User lastaccess JOIN
if ((strpos($sort, 'ul.timeaccess') === false) and (strpos($fields, 'ul.timeaccess') === false)) {
// user_lastaccess is not required MDL-13810
} else {
if ($iscoursepage) {
$joins[] = "LEFT OUTER JOIN {user_lastaccess} ul ON (ul.userid = u.id AND ul.courseid = {$context->instanceid})";
} else {
throw new coding_exception('Invalid sort in get_users_by_capability(), ul.timeaccess allowed only for course contexts.');
}
}
/// We never return deleted users or guest acount.
$wherecond[] = "u.deleted = 0 AND u.username <> 'guest'";
/// Groups
if ($groups) {
$groups = (array)$groups;
list($grouptest, $grpparams) = $DB->get_in_or_equal($groups, SQL_PARAMS_NAMED, 'grp000');
$grouptest = "u.id IN (SELECT userid FROM {groups_members} gm WHERE gm.groupid $grouptest)";
$params = array_merge($params, $grpparams);
if ($useviewallgroups) {
$viewallgroupsusers = get_users_by_capability($context, 'moodle/site:accessallgroups', 'u.id, u.id', '', '', '', '', $exceptions);
$wherecond[] = "($grouptest OR u.id IN (" . implode(',', array_keys($viewallgroupsusers)) . '))';
} else {
$wherecond[] = "($grouptest)";
}
}
/// User exceptions
if (!empty($exceptions)) {
$exceptions = (array)$exceptions;
list($exsql, $exparams) = $DB->get_in_or_equal($exceptions, SQL_PARAMS_NAMED, 'exc000', false);
$params = array_merge($params, $exparams);
$wherecond[] = "u.id $exsql";
}
// now add the needed and prohibited roles conditions as joins
if (!empty($needed['any'])) {
// simple case - there are no prohibits involved
if (!empty($needed['any'][$defaultuserroleid]) or ($isfrontpage and !empty($needed['any'][$defaultfrontpageroleid]))) {
// everybody
} else {
$joins[] = "JOIN (SELECT DISTINCT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (".implode(',', array_keys($needed['any'])) .")
) ra ON ra.userid = u.id";
}
} else {
$unions = array();
$everybody = false;
foreach ($needed as $cap=>$unused) {
if (empty($prohibited[$cap])) {
if (!empty($needed[$cap][$defaultuserroleid]) or ($isfrontpage and !empty($needed[$cap][$defaultfrontpageroleid]))) {
$everybody = true;
break;
} else {
$unions[] = "SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (".implode(',', array_keys($needed[$cap])) .")";
}
} else {
if (!empty($needed[$cap][$defaultuserroleid]) or ($isfrontpage and !empty($needed[$cap][$defaultfrontpageroleid]))) {
// everybody except the prohibitted - hiding does not matter
$unions[] = "SELECT id AS userid
FROM {user}
WHERE id NOT IN (SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (".implode(',', array_keys($prohibited[$cap])) ."))";
} else {
$unions[] = "SELECT userid
FROM {role_assignments}
WHERE contextid IN ($ctxids)
AND roleid IN (".implode(',', array_keys($needed[$cap])) .")
AND roleid NOT IN (".implode(',', array_keys($prohibited[$cap])) .")";
}
}
}
if (!$everybody) {
if (count($unions) > 1) {
$unions = implode(' UNION ', $unions);
} else {
$unions = reset($unions);
}
$joins[] = "JOIN (SELECT DISTINCT userid FROM ( $unions ) us) ra ON ra.userid = u.id";
}
}
// Collect WHERE conditions and needed joins
$where = implode(' AND ', $wherecond);
if ($where !== '') {
$where = 'WHERE ' . $where;
}
$joins = implode("\n", $joins);
/// Ok, let's get the users!
$sql = "SELECT $fields
FROM {user} u
$joins
$where
ORDER BY $sort";
return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
}
/**
* Re-sort a users array based on a sorting policy
*
* Will re-sort a $users results array (from get_users_by_capability(), usually)
* based on a sorting policy. This is to support the odd practice of
* sorting teachers by 'authority', where authority was "lowest id of the role
* assignment".
*
* Will execute 1 database query. Only suitable for small numbers of users, as it
* uses an u.id IN() clause.
*
* Notes about the sorting criteria.
*
* As a default, we cannot rely on role.sortorder because then
* admins/coursecreators will always win. That is why the sane
* rule "is locality matters most", with sortorder as 2nd
* consideration.
*
* If you want role.sortorder, use the 'sortorder' policy, and
* name explicitly what roles you want to cover. It's probably
* a good idea to see what roles have the capabilities you want
* (array_diff() them against roiles that have 'can-do-anything'
* to weed out admin-ish roles. Or fetch a list of roles from
* variables like $CFG->coursemanager .
*
* @global object
* @param array $users Users array, keyed on userid
* @param object $context
* @param array $roles ids of the roles to include, optional
* @param string $policy defaults to locality, more about
* @return array sorted copy of the array
*/
function sort_by_roleassignment_authority($users, $context, $roles=array(), $sortpolicy='locality') {
global $DB;
$userswhere = ' ra.userid IN (' . implode(',',array_keys($users)) . ')';
$contextwhere = 'AND ra.contextid IN ('.str_replace('/', ',',substr($context->path, 1)).')';
if (empty($roles)) {
$roleswhere = '';
} else {
$roleswhere = ' AND ra.roleid IN ('.implode(',',$roles).')';
}
$sql = "SELECT ra.userid
FROM {role_assignments} ra
JOIN {role} r
ON ra.roleid=r.id
JOIN {context} ctx
ON ra.contextid=ctx.id
WHERE $userswhere
$contextwhere
$roleswhere";
// Default 'locality' policy -- read PHPDoc notes
// about sort policies...
$orderby = 'ORDER BY '
.'ctx.depth DESC, ' /* locality wins */
.'r.sortorder ASC, ' /* rolesorting 2nd criteria */
.'ra.id'; /* role assignment order tie-breaker */
if ($sortpolicy === 'sortorder') {
$orderby = 'ORDER BY '
.'r.sortorder ASC, ' /* rolesorting 2nd criteria */
.'ra.id'; /* role assignment order tie-breaker */
}
$sortedids = $DB->get_fieldset_sql($sql . $orderby);
$sortedusers = array();
$seen = array();
foreach ($sortedids as $id) {
// Avoid duplicates
if (isset($seen[$id])) {
continue;
}
$seen[$id] = true;
// assign
$sortedusers[$id] = $users[$id];
}
return $sortedusers;
}
/**
* Gets all the users assigned this role in this context or higher
*
* @global object
* @param int $roleid (can also be an array of ints!)
* @param object $context
* @param bool $parent if true, get list of users assigned in higher context too
* @param string $fields fields from user (u.) , role assignment (ra) or role (r.)
* @param string $sort sort from user (u.) , role assignment (ra) or role (r.)
* @param bool $gethidden_ignored use enrolments instead
* @param string $group defaults to ''
* @param mixed $limitfrom defaults to ''
* @param mixed $limitnum defaults to ''
* @param string $extrawheretest defaults to ''
* @param string $whereparams defaults to ''
* @return array
*/
function get_role_users($roleid, $context, $parent=false, $fields='',
$sort='u.lastname, u.firstname', $gethidden_ignored=NULL, $group='',
$limitfrom='', $limitnum='', $extrawheretest='', $whereparams=array()) {
global $DB;
if (empty($fields)) {
$fields = 'u.id, u.confirmed, u.username, u.firstname, u.lastname, '.
'u.maildisplay, u.mailformat, u.maildigest, u.email, u.city, '.
'u.country, u.picture, u.idnumber, u.department, u.institution, '.
'u.emailstop, u.lang, u.timezone, u.lastaccess, u.mnethostid, r.name as rolename';
}
$parentcontexts = '';
if ($parent) {
$parentcontexts = substr($context->path, 1); // kill leading slash
$parentcontexts = str_replace('/', ',', $parentcontexts);
if ($parentcontexts !== '') {
$parentcontexts = ' OR ra.contextid IN ('.$parentcontexts.' )';
}
}
if ($roleid) {
list($rids, $params) = $DB->get_in_or_equal($roleid, SQL_PARAMS_QM);
$roleselect = "AND ra.roleid $rids";
} else {
$params = array();
$roleselect = '';
}
if ($group) {
$groupjoin = "JOIN {groups_members} gm ON gm.userid = u.id";
$groupselect = " AND gm.groupid = ? ";
$params[] = $group;
} else {
$groupjoin = '';
$groupselect = '';
}
array_unshift($params, $context->id);
if ($extrawheretest) {
$extrawheretest = ' AND ' . $extrawheretest;
$params = array_merge($params, $whereparams);
}
$sql = "SELECT $fields, ra.roleid
FROM {role_assignments} ra
JOIN {user} u ON u.id = ra.userid
JOIN {role} r ON ra.roleid = r.id
$groupjoin
WHERE (ra.contextid = ? $parentcontexts)
$roleselect
$groupselect
$extrawheretest
ORDER BY $sort"; // join now so that we can just use fullname() later
return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
}
/**
* Counts all the users assigned this role in this context or higher
*
* @global object
* @param mixed $roleid either int or an array of ints
* @param object $context
* @param bool $parent if true, get list of users assigned in higher context too
* @return int Returns the result count
*/
function count_role_users($roleid, $context, $parent=false) {
global $DB;
if ($parent) {
if ($contexts = get_parent_contexts($context)) {
$parentcontexts = ' OR r.contextid IN ('.implode(',', $contexts).')';
} else {
$parentcontexts = '';
}
} else {
$parentcontexts = '';
}
if ($roleid) {
list($rids, $params) = $DB->get_in_or_equal($roleid, SQL_PARAMS_QM);
$roleselect = "AND r.roleid $rids";
} else {
$params = array();
$roleselect = '';
}
array_unshift($params, $context->id);
$sql = "SELECT count(u.id)
FROM {role_assignments} r
JOIN {user} u ON u.id = r.userid
WHERE (r.contextid = ? $parentcontexts)
$roleselect
AND u.deleted = 0";
return $DB->count_records_sql($sql, $params);
}
/**
* This function gets the list of courses that this user has a particular capability in.
* It is still not very efficient.
*
* @global object
* @param string $capability Capability in question
* @param int $userid User ID or NULL for current user
* @param bool $doanything True if 'doanything' is permitted (default)
* @param string $fieldsexceptid Leave blank if you only need 'id' in the course records;
* otherwise use a comma-separated list of the fields you require, not including id
* @param string $orderby If set, use a comma-separated list of fields from course
* table with sql modifiers (DESC) if needed
* @return array Array of courses, may have zero entries. Or false if query failed.
*/
function get_user_capability_course($capability, $userid=NULL, $doanything=true, $fieldsexceptid='', $orderby='') {
global $DB;
// Convert fields list and ordering
$fieldlist = '';
if ($fieldsexceptid) {
$fields = explode(',', $fieldsexceptid);
foreach($fields as $field) {
$fieldlist .= ',c.'.$field;
}
}
if ($orderby) {
$fields = explode(',', $orderby);
$orderby = '';
foreach($fields as $field) {
if($orderby) {
$orderby .= ',';
}
$orderby .= 'c.'.$field;
}
$orderby = 'ORDER BY '.$orderby;
}
// Obtain a list of everything relevant about all courses including context.
// Note the result can be used directly as a context (we are going to), the course
// fields are just appended.
if (!$rs = $DB->get_recordset_sql("SELECT x.*, c.id AS courseid $fieldlist
FROM {course} c
INNER JOIN {context} x
ON (c.id=x.instanceid AND x.contextlevel=".CONTEXT_COURSE.")
$orderby")) {
return false;
}
// Check capability for each course in turn
$courses = array();
foreach ($rs as $coursecontext) {
if(has_capability($capability, $coursecontext, $userid, $doanything)) {
// We've got the capability. Make the record look like a course record
// and store it
$coursecontext->id = $coursecontext->courseid;
unset($coursecontext->courseid);
unset($coursecontext->contextlevel);
unset($coursecontext->instanceid);
$courses[] = $coursecontext;
}
}
$rs->close();
return $courses;
}
/** This function finds the roles assigned directly to this context only
* i.e. no parents role
*
* @global object
* @param object $context
* @return array
*/
function get_roles_on_exact_context($context) {
global $DB;
return $DB->get_records_sql("SELECT r.*
FROM {role_assignments} ra, {role} r
WHERE ra.roleid = r.id AND ra.contextid = ?",
array($context->id));
}
/**
* Switches the current user to another role for the current session and only
* in the given context.
*
* The caller *must* check
* - that this op is allowed
* - that the requested role can be switched to in this context (use get_switchable_roles)
* - that the requested role is NOT $CFG->defaultuserroleid
*
* To "unswitch" pass 0 as the roleid.
*
* This function *will* modify $USER->access - beware
*
* @global object
* @param integer $roleid the role to switch to.
* @param object $context the context in which to perform the switch.
* @return bool success or failure.
*/
function role_switch($roleid, $context) {
global $USER;
//
// Plan of action
//
// - Add the ghost RA to $USER->access
// as $USER->access['rsw'][$path] = $roleid
//
// - Make sure $USER->access['rdef'] has the roledefs
// it needs to honour the switcheroo
//
// Roledefs will get loaded "deep" here - down to the last child
// context. Note that
//
// - When visiting subcontexts, our selective accessdata loading
// will still work fine - though those ra/rdefs will be ignored
// appropriately while the switch is in place
//
// - If a switcheroo happens at a category with tons of courses
// (that have many overrides for switched-to role), the session
// will get... quite large. Sometimes you just can't win.
//
// To un-switch just unset($USER->access['rsw'][$path])
//
// Note: it is not possible to switch to roles that do not have course:view
// Add the switch RA
if (!isset($USER->access['rsw'])) {
$USER->access['rsw'] = array();
}
if ($roleid == 0) {
unset($USER->access['rsw'][$context->path]);
if (empty($USER->access['rsw'])) {
unset($USER->access['rsw']);
}
return true;
}
$USER->access['rsw'][$context->path]=$roleid;
// Load roledefs
$USER->access = get_role_access_bycontext($roleid, $context,
$USER->access);
return true;
}
/**
* Get any role that has an override on exact context
*
* @global object
* @param object $context
* @return array
*/
function get_roles_with_override_on_context($context) {
global $DB;
return $DB->get_records_sql("SELECT r.*
FROM {role_capabilities} rc, {role} r
WHERE rc.roleid = r.id AND rc.contextid = ?",
array($context->id));
}
/**
* Get all capabilities for this role on this context (overrides)
*
* @global object
* @param object $role
* @param object $context
* @return array
*/
function get_capabilities_from_role_on_context($role, $context) {
global $DB;
return $DB->get_records_sql("SELECT *
FROM {role_capabilities}
WHERE contextid = ? AND roleid = ?",
array($context->id, $role->id));
}
/**
* Find out which roles has assignment on this context
*
* @global object
* @param object $context
* @return array
*
*/
function get_roles_with_assignment_on_context($context) {
global $DB;
return $DB->get_records_sql("SELECT r.*
FROM {role_assignments} ra, {role} r
WHERE ra.roleid = r.id AND ra.contextid = ?",
array($context->id));
}
/**
* Find all user assignemnt of users for this role, on this context
*
* @global object
* @param object $role
* @param object $context
* @return array
*/
function get_users_from_role_on_context($role, $context) {
global $DB;
return $DB->get_records_sql("SELECT *
FROM {role_assignments}
WHERE contextid = ? AND roleid = ?",
array($context->id, $role->id));
}
/**
* Simple function returning a boolean true if roles exist, otherwise false
*
* @global object
* @param int $userid
* @param int $roleid
* @param int $contextid
* @return bool
*/
function user_has_role_assignment($userid, $roleid, $contextid=0) {
global $DB;
if ($contextid) {
return $DB->record_exists('role_assignments', array('userid'=>$userid, 'roleid'=>$roleid, 'contextid'=>$contextid));
} else {
return $DB->record_exists('role_assignments', array('userid'=>$userid, 'roleid'=>$roleid));
}
}
/**
* Get role name or alias if exists and format the text.
*
* @global object
* @param object $role role object
* @param object $coursecontext
* @return string name of role in course context
*/
function role_get_name($role, $coursecontext) {
global $DB;
if ($r = $DB->get_record('role_names', array('roleid'=>$role->id, 'contextid'=>$coursecontext->id))) {
return strip_tags(format_string($r->name));
} else {
return strip_tags(format_string($role->name));
}
}
/**
* Prepare list of roles for display, apply aliases and format text
*
* @global object
* @param array $roleoptions array roleid => rolename or roleid => roleobject
* @param object $context a context
* @return array Array of context-specific role names, or role objexts with a ->localname field added.
*/
function role_fix_names($roleoptions, $context, $rolenamedisplay=ROLENAME_ALIAS) {
global $DB;
// Make sure we are working with an array roleid => name. Normally we
// want to use the unlocalised name if the localised one is not present.
$newnames = array();
foreach ($roleoptions as $rid => $roleorname) {
if ($rolenamedisplay != ROLENAME_ALIAS_RAW) {
if (is_object($roleorname)) {
$newnames[$rid] = $roleorname->name;
} else {
$newnames[$rid] = $roleorname;
}
} else {
$newnames[$rid] = '';
}
}
// If necessary, get the localised names.
if ($rolenamedisplay != ROLENAME_ORIGINAL && !empty($context->id)) {
// Make sure we have a course context.
if ($context->contextlevel == CONTEXT_MODULE) {
if ($parentcontextid = array_shift(get_parent_contexts($context))) {
$context = get_context_instance_by_id($parentcontextid);
}
} else if ($context->contextlevel == CONTEXT_BLOCK) {
do {
if ($parentcontextid = array_shift(get_parent_contexts($context))) {
$context = get_context_instance_by_id($parentcontextid);
}
} while ($parentcontextid && $context->contextlevel != CONTEXT_COURSE);
}
// The get the relevant renames, and use them.
$aliasnames = $DB->get_records('role_names', array('contextid'=>$context->id));
foreach ($aliasnames as $alias) {
if (isset($newnames[$alias->roleid])) {
if ($rolenamedisplay == ROLENAME_ALIAS || $rolenamedisplay == ROLENAME_ALIAS_RAW) {
$newnames[$alias->roleid] = $alias->name;
} else if ($rolenamedisplay == ROLENAME_BOTH) {
$newnames[$alias->roleid] = $alias->name . ' (' . $roleoptions[$alias->roleid] . ')';
}
}
}
}
// Finally, apply format_string and put the result in the right place.
foreach ($roleoptions as $rid => $roleorname) {
if ($rolenamedisplay != ROLENAME_ALIAS_RAW) {
$newnames[$rid] = strip_tags(format_string($newnames[$rid]));
}
if (is_object($roleorname)) {
$roleoptions[$rid]->localname = $newnames[$rid];
} else {
$roleoptions[$rid] = $newnames[$rid];
}
}
return $roleoptions;
}
/**
* Aids in detecting if a new line is required when reading a new capability
*
* This function helps admin/roles/manage.php etc to detect if a new line should be printed
* when we read in a new capability.
* Most of the time, if the 2 components are different we should print a new line, (e.g. course system->rss client)
* but when we are in grade, all reports/import/export capabilites should be together
*
* @param string $cap component string a
* @param string $comp component string b
* @param mixed $contextlevel
* @return bool whether 2 component are in different "sections"
*/
function component_level_changed($cap, $comp, $contextlevel) {
if ($cap->component == 'enrol/authorize' && $comp =='enrol/authorize') {
return false;
}
if (strstr($cap->component, '/') && strstr($comp, '/')) {
$compsa = explode('/', $cap->component);
$compsb = explode('/', $comp);
// list of system reports
if (($compsa[0] == 'report') && ($compsb[0] == 'report')) {
return false;
}
// we are in gradebook, still
if (($compsa[0] == 'gradeexport' || $compsa[0] == 'gradeimport' || $compsa[0] == 'gradereport') &&
($compsb[0] == 'gradeexport' || $compsb[0] == 'gradeimport' || $compsb[0] == 'gradereport')) {
return false;
}
if (($compsa[0] == 'coursereport') && ($compsb[0] == 'coursereport')) {
return false;
}
}
return ($cap->component != $comp || $cap->contextlevel != $contextlevel);
}
/**
* Rebuild all related context depth and path caches
*
* @global object
* @param array $fixcontexts array of contexts, strongtyped
*/
function rebuild_contexts(array $fixcontexts) {
global $DB;
foreach ($fixcontexts as $context) {
if ($context->path) {
mark_context_dirty($context->path);
}
$DB->set_field_select('context', 'depth', 0, "path LIKE '%/$context->id/%'");
$DB->set_field('context', 'depth', 0, array('id'=>$context->id));
}
build_context_path(false);
}
/**
* Populate context.path and context.depth where missing.
*
* @param bool $force force a complete rebuild of the path and depth fields, defaults to false
*/
function build_context_path($force=false) {
global $CFG, $DB;
// System context
$sitectx = get_system_context(!$force);
$base = '/'.$sitectx->id;
// Sitecourse
$sitecoursectx = $DB->get_record('context', array('contextlevel'=>CONTEXT_COURSE, 'instanceid'=>SITEID));
if ($force || $sitecoursectx->path !== "$base/{$sitecoursectx->id}") {
$DB->set_field('context', 'path', "$base/{$sitecoursectx->id}", array('id'=>$sitecoursectx->id));
$DB->set_field('context', 'depth', 2, array('id'=>$sitecoursectx->id));
$sitecoursectx = $DB->get_record('context', array('contextlevel'=>CONTEXT_COURSE, 'instanceid'=>SITEID));
}
$ctxemptyclause = " AND (ctx.path IS NULL
OR ctx.depth=0) ";
$emptyclause = " AND ({context}.path IS NULL
OR {context}.depth=0) ";
if ($force) {
$ctxemptyclause = $emptyclause = '';
}
/* MDL-11347:
* - mysql does not allow to use FROM in UPDATE statements
* - using two tables after UPDATE works in mysql, but might give unexpected
* results in pg 8 (depends on configuration)
* - using table alias in UPDATE does not work in pg < 8.2
*
* Different code for each database - mostly for performance reasons
*/
$dbfamily = $DB->get_dbfamily();
if ($dbfamily == 'mysql') {
$updatesql = "UPDATE {context} ct, {context_temp} temp
SET ct.path = temp.path,
ct.depth = temp.depth
WHERE ct.id = temp.id";
} else if ($dbfamily == 'oracle') {
$updatesql = "UPDATE {context} ct
SET (ct.path, ct.depth) =
(SELECT temp.path, temp.depth
FROM {context_temp} temp
WHERE temp.id=ct.id)
WHERE EXISTS (SELECT 'x'
FROM {context_temp} temp
WHERE temp.id = ct.id)";
} else if ($dbfamily == 'postgres' or $dbfamily == 'mssql') {
$updatesql = "UPDATE {context}
SET path = temp.path,
depth = temp.depth
FROM {context_temp} temp
WHERE temp.id={context}.id";
} else {
// sqlite and others
$updatesql = "UPDATE {context}
SET path = (SELECT path FROM {context_temp} WHERE id = {context}.id),
depth = (SELECT depth FROM {context_temp} WHERE id = {context}.id)
WHERE id IN (SELECT id FROM mdl_context_temp)";
}
// Top level categories
$sql = "UPDATE {context}
SET depth=2, path=" . $DB->sql_concat("'$base/'", 'id') . "
WHERE contextlevel=".CONTEXT_COURSECAT."
AND EXISTS (SELECT 'x'
FROM {course_categories} cc
WHERE cc.id = {context}.instanceid
AND cc.depth=1)
$emptyclause";
$DB->execute($sql);
$DB->delete_records('context_temp');
// Deeper categories - one query per depthlevel
$maxdepth = $DB->get_field_sql("SELECT MAX(depth)
FROM {course_categories}");
for ($n=2; $n<=$maxdepth; $n++) {
$sql = "INSERT INTO {context_temp} (id, path, depth)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", $n+1
FROM {context} ctx
JOIN {course_categories} c ON ctx.instanceid=c.id
JOIN {context} pctx ON c.parent=pctx.instanceid
WHERE ctx.contextlevel=".CONTEXT_COURSECAT."
AND pctx.contextlevel=".CONTEXT_COURSECAT."
AND c.depth=$n
AND NOT EXISTS (SELECT 'x'
FROM {context_temp} temp
WHERE temp.id = ctx.id)
$ctxemptyclause";
$DB->execute($sql);
// this is needed after every loop
// MDL-11532
$DB->execute($updatesql);
$DB->delete_records('context_temp');
}
// Courses -- except sitecourse
$sql = "INSERT INTO {context_temp} (id, path, depth)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1
FROM {context} ctx
JOIN {course} c ON ctx.instanceid=c.id
JOIN {context} pctx ON c.category=pctx.instanceid
WHERE ctx.contextlevel=".CONTEXT_COURSE."
AND c.id!=".SITEID."
AND pctx.contextlevel=".CONTEXT_COURSECAT."
AND NOT EXISTS (SELECT 'x'
FROM {context_temp} temp
WHERE temp.id = ctx.id)
$ctxemptyclause";
$DB->execute($sql);
$DB->execute($updatesql);
$DB->delete_records('context_temp');
// Module instances
$sql = "INSERT INTO {context_temp} (id, path, depth)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1
FROM {context} ctx
JOIN {course_modules} cm ON ctx.instanceid=cm.id
JOIN {context} pctx ON cm.course=pctx.instanceid
WHERE ctx.contextlevel=".CONTEXT_MODULE."
AND pctx.contextlevel=".CONTEXT_COURSE."
AND NOT EXISTS (SELECT 'x'
FROM {context_temp} temp
WHERE temp.id = ctx.id)
$ctxemptyclause";
$DB->execute($sql);
$DB->execute($updatesql);
$DB->delete_records('context_temp');
// User
$sql = "UPDATE {context}
SET depth=2, path=".$DB->sql_concat("'$base/'", 'id')."
WHERE contextlevel=".CONTEXT_USER."
AND EXISTS (SELECT 'x'
FROM {user} u
WHERE u.id = {context}.instanceid)
$emptyclause ";
$DB->execute($sql);
// Blocks
$sql = "INSERT INTO {context_temp} (id, path, depth)
SELECT ctx.id, ".$DB->sql_concat('pctx.path', "'/'", 'ctx.id').", pctx.depth+1
FROM {context} ctx
JOIN {block_instances} bi ON ctx.instanceid = bi.id
JOIN {context} pctx ON bi.parentcontextid = pctx.id
WHERE ctx.contextlevel=".CONTEXT_BLOCK."
AND NOT EXISTS (SELECT 'x'
FROM {context_temp} temp
WHERE temp.id = ctx.id)
$ctxemptyclause";
$DB->execute($sql);
$DB->execute($updatesql);
$DB->delete_records('context_temp');
// reset static course cache - it might have incorrect cached data
global $ACCESSLIB_PRIVATE;
$ACCESSLIB_PRIVATE->contexts = array();
$ACCESSLIB_PRIVATE->contextsbyid = array();
}
/**
* Update the path field of the context and all dep. subcontexts that follow
*
* Update the path field of the context and
* all the dependent subcontexts that follow
* the move.
*
* The most important thing here is to be as
* DB efficient as possible. This op can have a
* massive impact in the DB.
*
* @global object
* @param obj $current context obj
* @param obj $newparent new parent obj
*
*/
function context_moved($context, $newparent) {
global $DB;
$frompath = $context->path;
$newpath = $newparent->path . '/' . $context->id;
$setdepth = '';
if (($newparent->depth +1) != $context->depth) {
$diff = $newparent->depth - $context->depth + 1;
$setdepth = ", depth = depth + $diff";
}
$sql = "UPDATE {context}
SET path = ?
$setdepth
WHERE path = ?";
$params = array($newpath, $frompath);
$DB->execute($sql, $params);
$sql = "UPDATE {context}
SET path = ".$DB->sql_concat("?", $DB->sql_substr("path", strlen($frompath)+1))."
$setdepth
WHERE path LIKE ?";
$params = array($newpath, "{$frompath}/%");
$DB->execute($sql, $params);
mark_context_dirty($frompath);
mark_context_dirty($newpath);
}
/**
* Preloads context information together with instances.
* NOTE: in future this function may return empty strings
* if we implement different caching.
*
* @param string $joinon for example 'u.id'
* @param string $contextlevel context level of instance in $joinon
* @param string $tablealias context table alias
* @return array with two values - select and join part
*/
function context_instance_preload_sql($joinon, $contextlevel, $tablealias) {
$select = ", $tablealias.id AS ctxid, $tablealias.path AS ctxpath, $tablealias.depth AS ctxdepth, $tablealias.contextlevel AS ctxlevel, $tablealias.instanceid AS ctxinstance";
$join = "LEFT JOIN {context} $tablealias ON ($tablealias.instanceid = $joinon AND $tablealias.contextlevel = $contextlevel)";
return array($select, $join);
}
/**
* Preloads context information from db record and strips the cached info.
* The db request has to ontain both the $join and $select from context_instance_preload_sql()
*
* @param object $rec
* @return void (modifies $rec)
*/
function context_instance_preload(stdClass $rec) {
if (empty($rec->ctxid)) {
// $rec does not have enough data, passed here repeatedly or context does not exist yet
return;
}
// note: in PHP5 the objects are passed by reference, no need to return $rec
$context = new object();
$context->id = $rec->ctxid; unset($rec->ctxid);
$context->path = $rec->ctxpath; unset($rec->ctxpath);
$context->depth = $rec->ctxdepth; unset($rec->ctxdepth);
$context->contextlevel = $rec->ctxlevel; unset($rec->ctxlevel);
$context->instanceid = $rec->ctxinstance; unset($rec->ctxinstance);
cache_context($context);
}
/**
* Fetch recent dirty contexts to know cheaply whether our $USER->access
* is stale and needs to be reloaded.
*
* Uses cache_flags
* @param int $time
* @return array Array of dirty contexts
*/
function get_dirty_contexts($time) {
return get_cache_flags('accesslib/dirtycontexts', $time-2);
}
/**
* Mark a context as dirty (with timestamp)
* so as to force reloading of the context.
*
* @global object
* @global object
* @param string $path context path
*/
function mark_context_dirty($path) {
global $CFG, $ACCESSLIB_PRIVATE;
if (during_initial_install()) {
return;
}
// only if it is a non-empty string
if (is_string($path) && $path !== '') {
set_cache_flag('accesslib/dirtycontexts', $path, 1, time()+$CFG->sessiontimeout);
if (isset($ACCESSLIB_PRIVATE->dirtycontexts)) {
$ACCESSLIB_PRIVATE->dirtycontexts[$path] = 1;
}
}
}
/**
* Will walk the contextpath to answer whether
* the contextpath is dirty
*
* @param array $contexts array of strings
* @param obj|array $dirty Dirty contexts from get_dirty_contexts()
* @return bool
*/
function is_contextpath_dirty($pathcontexts, $dirty) {
$path = '';
foreach ($pathcontexts as $ctx) {
$path = $path.'/'.$ctx;
if (isset($dirty[$path])) {
return true;
}
}
return false;
}
/**
* Fix the roles.sortorder field in the database, so it contains sequential integers,
* and return an array of roleids in order.
*
* @param array $allroles array of roles, as returned by get_all_roles();
* @return array $role->sortorder =-> $role->id with the keys in ascending order.
*/
function fix_role_sortorder($allroles) {
$rolesort = array();
$i = 0;
foreach ($allroles as $role) {
$rolesort[$i] = $role->id;
if ($role->sortorder != $i) {
$r = new object();
$r->id = $role->id;
$r->sortorder = $i;
$DB->update_record('role', $r);
$allroles[$role->id]->sortorder = $i;
}
$i++;
}
return $rolesort;
}
/**
* Switch the sort order of two roles (used in admin/roles/manage.php).
*
* @global object
* @param object $first The first role. Actually, only ->sortorder is used.
* @param object $second The second role. Actually, only ->sortorder is used.
* @return boolean success or failure
*/
function switch_roles($first, $second) {
global $DB;
$temp = $DB->get_field('role', 'MAX(sortorder) + 1', array());
$result = $DB->set_field('role', 'sortorder', $temp, array('sortorder' => $first->sortorder));
$result = $result && $DB->set_field('role', 'sortorder', $first->sortorder, array('sortorder' => $second->sortorder));
$result = $result && $DB->set_field('role', 'sortorder', $second->sortorder, array('sortorder' => $temp));
return $result;
}
/**
* duplicates all the base definitions of a role
*
* @global object
* @param object $sourcerole role to copy from
* @param int $targetrole id of role to copy to
*/
function role_cap_duplicate($sourcerole, $targetrole) {
global $DB;
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
$caps = $DB->get_records_sql("SELECT *
FROM {role_capabilities}
WHERE roleid = ? AND contextid = ?",
array($sourcerole->id, $systemcontext->id));
// adding capabilities
foreach ($caps as $cap) {
unset($cap->id);
$cap->roleid = $targetrole;
$DB->insert_record('role_capabilities', $cap);
}
}
/**
* Returns two lists, this can be used to find out if user has capability.
* Having any neede role and no forbidden role in this context means
* user has this capability in this context,
*
* @param object $context
* @param string $capability
* @return array($neededroles, $forbiddenroles)
*/
function get_roles_with_cap_in_context($context, $capability) {
global $DB;
$ctxids = trim($context->path, '/'); // kill leading slash
$ctxids = str_replace('/', ',', $ctxids);
$sql = "SELECT rc.id, rc.roleid, rc.permission, ctx.depth
FROM {role_capabilities} rc
JOIN {context} ctx ON ctx.id = rc.contextid
WHERE rc.capability = :cap AND ctx.id IN ($ctxids)
ORDER BY rc.roleid ASC, ctx.depth DESC";
$params = array('cap'=>$capability);
if (!$capdefs = $DB->get_records_sql($sql, $params)) {
// no cap definitions --> no capability
return array(array(), array());
}
$forbidden = array();
$needed = array();
foreach($capdefs as $def) {
if (isset($forbidden[$def->roleid])) {
continue;
}
if ($def->permission == CAP_PROHIBIT) {
$forbidden[$def->roleid] = $def->roleid;
unset($needed[$def->roleid]);
continue;
}
if (!isset($needed[$def->roleid])) {
if ($def->permission == CAP_ALLOW) {
$needed[$def->roleid] = true;
} else if ($def->permission == CAP_PREVENT) {
$needed[$def->roleid] = false;
}
}
}
unset($capdefs);
// remove all those roles not allowing
foreach($needed as $key=>$value) {
if (!$value) {
unset($needed[$key]);
} else {
$needed[$key] = $key;
}
}
return array($needed, $forbidden);
}
/**
* This function verifies the prohibit comes from this context
* and there are no more prohibits in parent contexts.
* @param object $context
* @param string $capability name
* @return bool
*/
function prohibit_is_removable($roleid, $context, $capability) {
global $DB;
$ctxids = trim($context->path, '/'); // kill leading slash
$ctxids = str_replace('/', ',', $ctxids);
$params = array('roleid'=>$roleid, 'cap'=>$capability, 'prohibit'=>CAP_PROHIBIT);
$sql = "SELECT ctx.id
FROM {role_capabilities} rc
JOIN {context} ctx ON ctx.id = rc.contextid
WHERE rc.roleid = :roleid AND rc.permission = :prohibit AND rc.capability = :cap AND ctx.id IN ($ctxids)
ORDER BY ctx.depth DESC";
if (!$prohibits = $DB->get_records_sql($sql, $params)) {
// no prohibits == nothing to remove
return true;
}
if (count($prohibits) > 1) {
// more prohibints can not be removed
return false;
}
return !empty($prohibits[$context->id]);
}
/**
* More user friendly role permission changing,
* it should produce as few overrides as possible.
* @param int $roleid
* @param object $context
* @param string $capname capability name
* @param int $permission
* @return void
*/
function role_change_permission($roleid, $context, $capname, $permission) {
global $DB;
if ($permission == CAP_INHERIT) {
unassign_capability($capname, $roleid, $context->id);
mark_context_dirty($context->path);
return;
}
$ctxids = trim($context->path, '/'); // kill leading slash
$ctxids = str_replace('/', ',', $ctxids);
$params = array('roleid'=>$roleid, 'cap'=>$capname);
$sql = "SELECT ctx.id, rc.permission, ctx.depth
FROM {role_capabilities} rc
JOIN {context} ctx ON ctx.id = rc.contextid
WHERE rc.roleid = :roleid AND rc.capability = :cap AND ctx.id IN ($ctxids)
ORDER BY ctx.depth DESC";
if ($existing = $DB->get_records_sql($sql, $params)) {
foreach($existing as $e) {
if ($e->permission == CAP_PROHIBIT) {
// prohibit can not be overridden, no point in changing anything
return;
}
}
$lowest = array_shift($existing);
if ($lowest->permission == $permission) {
// permission already set in this context or parent - nothing to do
return;
}
if ($existing) {
$parent = array_shift($existing);
if ($parent->permission == $permission) {
// permission already set in parent context or parent - just unset in this context
// we do this because we want as few overrides as possible for performance reasons
unassign_capability($capname, $roleid, $context->id);
mark_context_dirty($context->path);
return;
}
}
} else {
if ($permission == CAP_PREVENT) {
// nothing means role does not have permission
return;
}
}
// assign the needed capability
assign_capability($capname, $permission, $roleid, $context->id, true);
// force cap reloading
mark_context_dirty($context->path);
}