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moodle/lib/accesslib.php
tjhunt 115faa2f7b Fix column names.
2006-11-20 17:47:30 +00:00

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<?php
/**
* Capability session information format
* 2 x 2 array
* [context][capability]
* where context is the context id of the table 'context'
* and capability is a string defining the capability
* e.g.
*
* [Capabilities] => [26][mod/forum:viewpost] = 1
* [26][mod/forum:startdiscussion] = -8990
* [26][mod/forum:editallpost] = -1
* [273][moodle:blahblah] = 1
* [273][moodle:blahblahblah] = 2
*/
// permission definitions
define('CAP_INHERIT', 0);
define('CAP_ALLOW', 1);
define('CAP_PREVENT', -1);
define('CAP_PROHIBIT', -1000);
// context definitions
define('CONTEXT_SYSTEM', 10);
define('CONTEXT_PERSONAL', 20);
define('CONTEXT_USER', 30);
define('CONTEXT_COURSECAT', 40);
define('CONTEXT_COURSE', 50);
define('CONTEXT_GROUP', 60);
define('CONTEXT_MODULE', 70);
define('CONTEXT_BLOCK', 80);
// capability risks - see http://docs.moodle.org/en/Hardening_new_Roles_system
define('RISK_MANAGETRUST', 0x0001);
define('RISK_CONFIG', 0x0002);
define('RISK_XSS', 0x0004);
define('RISK_PERSONAL', 0x0008);
define('RISK_SPAM', 0x0010);
$context_cache = array(); // Cache of all used context objects for performance (by level and instance)
$context_cache_id = array(); // Index to above cache by id
/**
* Loads the capabilities for the default guest role to the current user in a specific context
* @return object
*/
function load_guest_role($context=NULL) {
global $USER;
static $guestrole;
if (!isloggedin()) {
return false;
}
if (!$sitecontext = get_context_instance(CONTEXT_SYSTEM)) {
return false;
}
if (empty($context)) {
$context = $sitecontext;
}
if (empty($guestrole)) {
if (!$guestrole = get_guest_role()) {
return false;
}
}
if ($capabilities = get_records_select('role_capabilities',
"roleid = $guestrole->id AND contextid = $sitecontext->id")) {
foreach ($capabilities as $capability) {
$USER->capabilities[$context->id][$capability->capability] = $capability->permission;
}
}
return true;
}
/**
* Load default not logged in role capabilities when user is not logged in
* @return bool
*/
function load_notloggedin_role() {
global $CFG, $USER;
if (!$sitecontext = get_context_instance(CONTEXT_SYSTEM)) {
return false;
}
if (empty($CFG->notloggedinroleid)) { // Let's set the default to the guest role
if ($role = get_guest_role()) {
set_config('notloggedinroleid', $role->id);
} else {
return false;
}
}
if ($capabilities = get_records_select('role_capabilities',
"roleid = $CFG->notloggedinroleid AND contextid = $sitecontext->id")) {
foreach ($capabilities as $capability) {
$USER->capabilities[$sitecontext->id][$capability->capability] = $capability->permission;
}
}
return true;
}
/**
* Load default not logged in role capabilities when user is not logged in
* @return bool
*/
function load_defaultuser_role() {
global $CFG, $USER;
if (!$sitecontext = get_context_instance(CONTEXT_SYSTEM)) {
return false;
}
if (empty($CFG->defaultuserroleid)) { // Let's set the default to the guest role
if ($role = get_guest_role()) {
set_config('defaultuserroleid', $role->id);
} else {
return false;
}
}
if ($capabilities = get_records_select('role_capabilities',
"roleid = $CFG->defaultuserroleid AND contextid = $sitecontext->id AND permission <> 0")) {
// Find out if this default role is a guest role, for the hack below
$defaultisguestrole=false;
foreach ($capabilities as $capability) {
if($capability->capability=='moodle/legacy:guest') {
$defaultisguestrole=true;
}
}
foreach ($capabilities as $capability) {
// If the default role is a guest role, then don't copy legacy:guest,
// otherwise this user could get confused with a REAL guest. Also don't copy
// course:view, which is a hack that's necessary because guest roles are
// not really handled properly (see MDL-7513)
if($defaultisguestrole && $USER->username!='guest' &&
($capability->capability=='moodle/legacy:guest' ||
$capability->capability=='moodle/course:view')) {
continue;
}
// Don't overwrite capabilities from real role...
if (!isset($USER->capabilities[$sitecontext->id][$capability->capability])) {
$USER->capabilities[$sitecontext->id][$capability->capability] = $capability->permission;
}
}
}
return true;
}
/**
* Get the default guest role
* @return object role
*/
function get_guest_role() {
if ($roles = get_roles_with_capability('moodle/legacy:guest', CAP_ALLOW)) {
return array_shift($roles); // Pick the first one
} else {
return false;
}
}
/**
* This functions get all the course categories in proper order
* (!)note this only gets course category contexts, and not the site
* context
* @param object $context
* @param int $type
* @return array of contextids
*/
function get_parent_cats($context, $type) {
$parents = array();
switch ($type) {
// a category can be the parent of another category
// there is no limit of depth in this case
case CONTEXT_COURSECAT:
if (!$cat = get_record('course_categories','id',$context->instanceid)) {
break;
}
while (!empty($cat->parent)) {
if (!$context = get_context_instance(CONTEXT_COURSECAT, $cat->parent)) {
break;
}
$parents[] = $context->id;
$cat = get_record('course_categories','id',$cat->parent);
}
break;
// a course always fall into a category, unless it's a site course
// this happens when SITEID = $course->id
// in this case the parent of the course is site context
case CONTEXT_COURSE:
if (!$course = get_record('course', 'id', $context->instanceid)) {
break;
}
if (!$catinstance = get_context_instance(CONTEXT_COURSECAT, $course->category)) {
break;
}
$parents[] = $catinstance->id;
if (!$cat = get_record('course_categories','id',$course->category)) {
break;
}
// Yu: Separating site and site course context
if ($course->id == SITEID) {
break;
}
while (!empty($cat->parent)) {
if (!$context = get_context_instance(CONTEXT_COURSECAT, $cat->parent)) {
break;
}
$parents[] = $context->id;
$cat = get_record('course_categories','id',$cat->parent);
}
break;
default:
break;
}
return array_reverse($parents);
}
/**
* This function checks for a capability assertion being true. If it isn't
* then the page is terminated neatly with a standard error message
* @param string $capability - name of the capability
* @param object $context - a context object (record from context table)
* @param integer $userid - a userid number
* @param bool $doanything - if false, ignore do anything
* @param string $errorstring - an errorstring
* @param string $stringfile - which stringfile to get it from
*/
function require_capability($capability, $context=NULL, $userid=NULL, $doanything=true,
$errormessage='nopermissions', $stringfile='') {
global $USER, $CFG;
/// If the current user is not logged in, then make sure they are (if needed)
if (empty($userid) and empty($USER->capabilities)) {
if ($context && ($context->contextlevel == CONTEXT_COURSE)) {
require_login($context->instanceid);
} else if ($context && ($context->contextlevel == CONTEXT_MODULE)) {
if ($cm = get_record('course_modules','id',$context->instanceid)) {
if (!$course = get_record('course', 'id', $cm->course)) {
error('Incorrect course.');
}
require_course_login($course, true, $cm);
} else {
require_login();
}
} else if ($context && ($context->contextlevel == CONTEXT_SYSTEM)) {
if (!empty($CFG->forcelogin)) {
require_login();
}
} else {
require_login();
}
}
/// OK, if they still don't have the capability then print a nice error message
if (!has_capability($capability, $context, $userid, $doanything)) {
$capabilityname = get_capability_string($capability);
print_error($errormessage, $stringfile, '', $capabilityname);
}
}
/**
* This function returns whether the current user has the capability of performing a function
* For example, we can do has_capability('mod/forum:replypost',$cm) in forum
* only one of the 4 (moduleinstance, courseid, site, userid) would be set at 1 time
* This is a recursive funciton.
* @uses $USER
* @param string $capability - name of the capability
* @param object $context - a context object (record from context table)
* @param integer $userid - a userid number
* @param bool $doanything - if false, ignore do anything
* @return bool
*/
function has_capability($capability, $context=NULL, $userid=NULL, $doanything=true) {
global $USER, $CONTEXT, $CFG;
static $capcache = array(); // Cache of capabilities
/// Some sanity checks
if (debugging()) {
if ($capability == 'debugcache') {
print_object($capcache);
return true;
}
if (!record_exists('capabilities', 'name', $capability)) {
debugging('Capability "'.$capability.'" was not found! This should be fixed in code.');
}
if ($doanything != true and $doanything != false) {
debugging('Capability parameter "doanything" is wierd ("'.$doanything.'"). This should be fixed in code.');
}
if (!is_object($context) && $context !== NULL) {
debugging('Incorrect context parameter "'.$context.'" for has_capability(), object expected! This should be fixed in code.');
}
}
/// Make sure we know the current context
if (empty($context)) { // Use default CONTEXT if none specified
if (empty($CONTEXT)) {
return false;
} else {
$context = $CONTEXT;
}
} else { // A context was given to us
if (empty($CONTEXT)) {
$CONTEXT = $context; // Store FIRST used context in this global as future default
}
}
/// Check and return cache in case we've processed this one before.
$cachekey = $capability.'_'.$context->id.'_'.intval($userid).'_'.intval($doanything);
if (isset($capcache[$cachekey])) {
return $capcache[$cachekey];
}
/// Set up user's default roles
if (empty($userid) && empty($USER->capabilities)) { // Real user, first time here
if (isloggedin()) {
load_defaultuser_role(); // All users get this by default
} else {
load_notloggedin_role(); // others get this by default
}
}
/// Load up the capabilities list or item as necessary
if ($userid && (($USER === NULL) or ($userid != $USER->id))) {
if (empty($USER->id) or ($userid != $USER->id)) {
$capabilities = load_user_capability($capability, $context, $userid); // expensive
} else { //$USER->id == $userid
$capabilities = empty($USER->capabilities) ? NULL : $USER->capabilities;
}
} else { // no userid
$capabilities = empty($USER->capabilities) ? NULL : $USER->capabilities;
$userid = $USER->id;
}
/// First deal with the "doanything" capability
if ($doanything) {
/// First make sure that we aren't in a "switched role"
$switchroleactive = false; // Assume it isn't active in this context
if (!empty($USER->switchrole)) { // Switchrole is active somewhere!
if (!empty($USER->switchrole[$context->id])) { // Because of current context
$switchroleactive = true;
} else { // Check parent contexts
if ($parentcontextids = get_parent_contexts($context)) {
foreach ($parentcontextids as $parentcontextid) {
if (!empty($USER->switchrole[$parentcontextid])) { // Yep, switchroles active here
$switchroleactive = true;
break;
}
}
}
}
}
/// Check the site context for doanything (most common) first
if (empty($switchroleactive)) { // Ignore site setting if switchrole is active
$sitecontext = get_context_instance(CONTEXT_SYSTEM);
if (isset($capabilities[$sitecontext->id]['moodle/site:doanything'])) {
$result = (0 < $capabilities[$sitecontext->id]['moodle/site:doanything']);
$capcache[$cachekey] = $result;
return $result;
}
}
/// If it's not set at site level, it is possible to be set on other levels
/// Though this usage is not common and can cause risks
switch ($context->contextlevel) {
case CONTEXT_COURSECAT:
// Check parent cats.
$parentcats = get_parent_cats($context, CONTEXT_COURSECAT);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['moodle/site:doanything'])) {
$result = (0 < $capabilities[$parentcat]['moodle/site:doanything']);
$capcache[$cachekey] = $result;
return $result;
}
}
break;
case CONTEXT_COURSE:
// Check parent cat.
$parentcats = get_parent_cats($context, CONTEXT_COURSE);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
$result = (0 < $capabilities[$parentcat]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
}
break;
case CONTEXT_GROUP:
// Find course.
$group = get_record('groups','id',$context->instanceid);
$courseinstance = get_context_instance(CONTEXT_COURSE, $group->courseid);
$parentcats = get_parent_cats($courseinstance, CONTEXT_COURSE);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
$result = (0 < $capabilities[$parentcat]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
}
$coursecontext = '';
if (isset($capabilities[$courseinstance->id]['do_anything'])) {
$result = (0 < $capabilities[$courseinstance->id]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
break;
case CONTEXT_MODULE:
// Find course.
$cm = get_record('course_modules', 'id', $context->instanceid);
$courseinstance = get_context_instance(CONTEXT_COURSE, $cm->course);
if ($parentcats = get_parent_cats($courseinstance, CONTEXT_COURSE)) {
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
$result = (0 < $capabilities[$parentcat]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
}
}
if (isset($capabilities[$courseinstance->id]['do_anything'])) {
$result = (0 < $capabilities[$courseinstance->id]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
break;
case CONTEXT_BLOCK:
// not necessarily 1 to 1 to course.
$block = get_record('block_instance','id',$context->instanceid);
if ($block->pagetype == 'course-view') {
$courseinstance = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
$parentcats = get_parent_cats($courseinstance, CONTEXT_COURSE);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
$result = (0 < $capabilities[$parentcat]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
}
if (isset($capabilities[$courseinstance->id]['do_anything'])) {
$result = (0 < $capabilities[$courseinstance->id]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
} else { // if not course-view type of blocks, check site
if (isset($capabilities[$sitecontext->id]['do_anything'])) {
$result = (0 < $capabilities[$sitecontext->id]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
}
break;
default:
// CONTEXT_SYSTEM: CONTEXT_PERSONAL: CONTEXT_USER:
// Do nothing, because the parents are site context
// which has been checked already
break;
}
// Last: check self.
if (isset($capabilities[$context->id]['do_anything'])) {
$result = (0 < $capabilities[$context->id]['do_anything']);
$capcache[$cachekey] = $result;
return $result;
}
}
/// do_anything has not been set, we now look for it the normal way. (checking individual capability)
$result = (0 < capability_search($capability, $context, $capabilities));
$capcache[$cachekey] = $result;
return $result;
}
/**
* In a separate function so that we won't have to deal with do_anything.
* again. Used by function has_capability().
* @param $capability - capability string
* @param $context - the context object
* @param $capabilities - either $USER->capability or loaded array (for other users)
* @return permission (int)
*/
function capability_search($capability, $context, $capabilities) {
global $USER, $CFG;
if (!isset($context->id)) {
return 0;
}
// if already set in the array explicitly, no need to look for it in parent
// context any longer
if (isset($capabilities[$context->id][$capability])) {
return ($capabilities[$context->id][$capability]);
}
/* Then, we check the cache recursively */
$permission = 0;
switch ($context->contextlevel) {
case CONTEXT_SYSTEM: // by now it's a definite an inherit
$permission = 0;
break;
case CONTEXT_PERSONAL:
$parentcontext = get_context_instance(CONTEXT_SYSTEM);
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
case CONTEXT_USER:
$parentcontext = get_context_instance(CONTEXT_SYSTEM);
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
case CONTEXT_COURSECAT: // Coursecat -> coursecat or site
$coursecat = get_record('course_categories','id',$context->instanceid);
if (!empty($coursecat->parent)) { // return parent value if it exists
$parentcontext = get_context_instance(CONTEXT_COURSECAT, $coursecat->parent);
} else { // else return site value
$parentcontext = get_context_instance(CONTEXT_SYSTEM);
}
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
case CONTEXT_COURSE: // 1 to 1 to course cat
// find the course cat, and return its value
$course = get_record('course','id',$context->instanceid);
// Yu: Separating site and site course context
if ($course->id == SITEID) {
$parentcontext = get_context_instance(CONTEXT_SYSTEM);
} else {
$parentcontext = get_context_instance(CONTEXT_COURSECAT, $course->category);
}
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
case CONTEXT_GROUP: // 1 to 1 to course
$group = get_record('groups','id',$context->instanceid);
$parentcontext = get_context_instance(CONTEXT_COURSE, $group->courseid);
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
case CONTEXT_MODULE: // 1 to 1 to course
$cm = get_record('course_modules','id',$context->instanceid);
$parentcontext = get_context_instance(CONTEXT_COURSE, $cm->course);
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
case CONTEXT_BLOCK: // not necessarily 1 to 1 to course
$block = get_record('block_instance','id',$context->instanceid);
if ($block->pagetype == 'course-view') {
$parentcontext = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
} else {
$parentcontext = get_context_instance(CONTEXT_SYSTEM);
}
$permission = capability_search($capability, $parentcontext, $capabilities);
break;
default:
error ('This is an unknown context!');
return false;
}
return $permission;
}
/**
* auxillary function for load_user_capabilities()
* checks if context c1 is a parent (or itself) of context c2
* @param int $c1 - context id of context 1
* @param int $c2 - context id of context 2
* @return bool
*/
function is_parent_context($c1, $c2) {
static $parentsarray;
// context can be itself and this is ok
if ($c1 == $c2) {
return true;
}
// hit in cache?
if (isset($parentsarray[$c1][$c2])) {
return $parentsarray[$c1][$c2];
}
if (!$co2 = get_record('context', 'id', $c2)) {
return false;
}
if (!$parents = get_parent_contexts($co2)) {
return false;
}
foreach ($parents as $parent) {
$parentsarray[$parent][$c2] = true;
}
if (in_array($c1, $parents)) {
return true;
} else { // else not a parent, set the cache anyway
$parentsarray[$c1][$c2] = false;
return false;
}
}
/*
* auxillary function for load_user_capabilities()
* handler in usort() to sort contexts according to level
* @param object contexta
* @param object contextb
* @return int
*/
function roles_context_cmp($contexta, $contextb) {
if ($contexta->contextlevel == $contextb->contextlevel) {
return 0;
}
return ($contexta->contextlevel < $contextb->contextlevel) ? -1 : 1;
}
/**
* This function should be called immediately after a login, when $USER is set.
* It will build an array of all the capabilities at each level
* i.e. site/metacourse/course_category/course/moduleinstance
* Note we should only load capabilities if they are explicitly assigned already,
* we should not load all module's capability!
*
* [Capabilities] => [26][forum_post] = 1
* [26][forum_start] = -8990
* [26][forum_edit] = -1
* [273][blah blah] = 1
* [273][blah blah blah] = 2
*
* @param $capability string - Only get a specific capability (string)
* @param $context object - Only get capabilities for a specific context object
* @param $userid integer - the id of the user whose capabilities we want to load
* @return array of permissions (or nothing if they get assigned to $USER)
*/
function load_user_capability($capability='', $context = NULL, $userid='') {
global $USER, $CFG;
// this flag has not been set!
// (not clean install, or upgraded successfully to 1.7 and up)
if (empty($CFG->rolesactive)) {
return false;
}
if (empty($userid)) {
if (empty($USER->id)) { // We have no user to get capabilities for
debugging('User not logged in for load_user_capability!');
return false;
}
unset($USER->capabilities); // We don't want possible older capabilites hanging around
check_enrolment_plugins($USER); // Call "enrol" system to ensure that we have the correct picture
$userid = $USER->id;
$otheruserid = false;
} else {
if (!$user = get_record('user', 'id', $userid)) {
debugging('Non-existent userid in load_user_capability!');
return false;
}
check_enrolment_plugins($user); // Ensure that we have the correct picture
$otheruserid = $userid;
}
/// First we generate a list of all relevant contexts of the user
$usercontexts = array();
if ($context) { // if context is specified
$usercontexts = get_parent_contexts($context);
$usercontexts[] = $context->id; // Add the current context as well
} else { // else, we load everything
if ($userroles = get_records('role_assignments','userid',$userid)) {
foreach ($userroles as $userrole) {
$usercontexts[] = $userrole->contextid;
}
}
}
/// Set up SQL fragments for searching contexts
if ($usercontexts) {
$listofcontexts = '('.implode(',', $usercontexts).')';
$searchcontexts1 = "c1.id IN $listofcontexts AND";
} else {
$searchcontexts1 = '';
}
if ($capability) {
$capsearch = " AND rc.capability = '$capability' ";
} else {
$capsearch ="";
}
/// Set up SQL fragments for timestart, timeend etc
$now = time();
$timesql = "AND ((ra.timestart = 0 OR ra.timestart < $now) AND (ra.timeend = 0 OR ra.timeend > $now))";
/// Then we use 1 giant SQL to bring out all relevant capabilities.
/// The first part gets the capabilities of orginal role.
/// The second part gets the capabilities of overriden roles.
$siteinstance = get_context_instance(CONTEXT_SYSTEM);
$capabilities = array(); // Reinitialize.
// SQL for normal capabilities
$SQL1 = "SELECT rc.capability, c1.id as id1, c1.id as id2, (c1.contextlevel * 100) AS aggrlevel,
SUM(rc.permission) AS sum
FROM
{$CFG->prefix}role_assignments ra,
{$CFG->prefix}role_capabilities rc,
{$CFG->prefix}context c1
WHERE
ra.contextid=c1.id AND
ra.roleid=rc.roleid AND
ra.userid=$userid AND
$searchcontexts1
rc.contextid=$siteinstance->id
$capsearch
$timesql
GROUP BY
rc.capability, (c1.contextlevel * 100), c1.id
HAVING
SUM(rc.permission) != 0
ORDER BY
aggrlevel ASC";
if (!$rs = get_recordset_sql($SQL1)) {
error("Query failed in load_user_capability.");
}
if ($rs && $rs->RecordCount() > 0) {
while (!$rs->EOF) {
$array = $rs->fields;
$temprecord = new object;
foreach ($array as $key=>$val) {
if ($key == 'aggrlevel') {
$temprecord->contextlevel = $val;
} else {
$temprecord->{$key} = $val;
}
}
$capabilities[] = $temprecord;
$rs->MoveNext();
}
}
// SQL for overrides
// this is take out because we have no way of making sure c1 is indeed related to c2 (parent)
// if we do not group by sum, it is possible to have multiple records of rc.capability, c1.id, c2.id, tuple having
// different values, we can maually sum it when we go through the list
$SQL2 = "SELECT rc.capability, c1.id as id1, c2.id as id2, (c1.contextlevel * 100 + c2.contextlevel) AS aggrlevel,
rc.permission AS sum
FROM
{$CFG->prefix}role_assignments ra,
{$CFG->prefix}role_capabilities rc,
{$CFG->prefix}context c1,
{$CFG->prefix}context c2
WHERE
ra.contextid=c1.id AND
ra.roleid=rc.roleid AND
ra.userid=$userid AND
rc.contextid=c2.id AND
$searchcontexts1
rc.contextid != $siteinstance->id
$capsearch
$timesql
GROUP BY
rc.capability, (c1.contextlevel * 100 + c2.contextlevel), c1.id, c2.id, rc.permission
ORDER BY
aggrlevel ASC
";
if (!$rs = get_recordset_sql($SQL2)) {
error("Query failed in load_user_capability.");
}
if ($rs && $rs->RecordCount() > 0) {
while (!$rs->EOF) {
$array = $rs->fields;
$temprecord = new object;
foreach ($array as $key=>$val) {
if ($key == 'aggrlevel') {
$temprecord->contextlevel = $val;
} else {
$temprecord->{$key} = $val;
}
}
// for overrides, we have to make sure that context2 is a child of context1
// otherwise the combination makes no sense
if (is_parent_context($temprecord->id1, $temprecord->id2)) {
$capabilities[] = $temprecord;
} // only write if relevant
$rs->MoveNext();
}
}
// this step sorts capabilities according to the contextlevel
// it is very important because the order matters when we
// go through each capabilities later. (i.e. higher level contextlevel
// will override lower contextlevel settings
usort($capabilities, 'roles_context_cmp');
/* so up to this point we should have somethign like this
* $capabilities[1] ->contextlevel = 1000
->module = SITEID
->capability = do_anything
->id = 1 (id is the context id)
->sum = 0
* $capabilities[2] ->contextlevel = 1000
->module = SITEID
->capability = post_messages
->id = 1
->sum = -9000
* $capabilittes[3] ->contextlevel = 3000
->module = course
->capability = view_course_activities
->id = 25
->sum = 1
* $capabilittes[4] ->contextlevel = 3000
->module = course
->capability = view_course_activities
->id = 26
->sum = 0 (this is another course)
* $capabilities[5] ->contextlevel = 3050
->module = course
->capability = view_course_activities
->id = 25 (override in course 25)
->sum = -1
* ....
* now we proceed to write the session array, going from top to bottom
* at anypoint, we need to go up and check parent to look for prohibit
*/
// print_object($capabilities);
/* This is where we write to the actualy capabilities array
* what we need to do from here on is
* going down the array from lowest level to highest level
* 1) recursively check for prohibit,
* if any, we write prohibit
* else, we write the value
* 2) at an override level, we overwrite current level
* if it's not set to prohibit already, and if different
* ........ that should be it ........
*/
// This is the flag used for detecting the current context level. Since we are going through
// the array in ascending order of context level. For normal capabilities, there should only
// be 1 value per (capability, contextlevel, context), because they are already summed. But,
// for overrides, since we are processing them separate, we need to sum the relevcant entries.
// We set this flag when we hit a new level.
// If the flag is already set, we keep adding (summing), otherwise, we just override previous
// settings (from lower level contexts)
$capflags = array(); // (contextid, contextlevel, capability)
$usercap = array(); // for other user's capabilities
foreach ($capabilities as $capability) {
if (!$context = get_context_instance_by_id($capability->id2)) {
continue; // incorrect stale context
}
if (!empty($otheruserid)) { // we are pulling out other user's capabilities, do not write to session
if (capability_prohibits($capability->capability, $context, $capability->sum, $usercap)) {
$usercap[$capability->id2][$capability->capability] = CAP_PROHIBIT;
continue;
}
if (isset($usercap[$capability->id2][$capability->capability])) { // use isset because it can be sum 0
if (!empty($capflags[$capability->id2][$capability->contextlevel][$capability->capability])) {
$usercap[$capability->id2][$capability->capability] += $capability->sum;
} else { // else we override, and update flag
$usercap[$capability->id2][$capability->capability] = $capability->sum;
$capflags[$capability->id2][$capability->contextlevel][$capability->capability] = true;
}
} else {
$usercap[$capability->id2][$capability->capability] = $capability->sum;
$capflags[$capability->id2][$capability->contextlevel][$capability->capability] = true;
}
} else {
if (capability_prohibits($capability->capability, $context, $capability->sum)) { // if any parent or parent's parent is set to prohibit
$USER->capabilities[$capability->id2][$capability->capability] = CAP_PROHIBIT;
continue;
}
// if no parental prohibit set
// just write to session, i am not sure this is correct yet
// since 3050 shows up after 3000, and 3070 shows up after 3050,
// it should be ok just to overwrite like this, provided that there's no
// parental prohibits
// we need to write even if it's 0, because it could be an inherit override
if (isset($USER->capabilities[$capability->id2][$capability->capability])) {
if (!empty($capflags[$capability->id2][$capability->contextlevel][$capability->capability])) {
$USER->capabilities[$capability->id2][$capability->capability] += $capability->sum;
} else { // else we override, and update flag
$USER->capabilities[$capability->id2][$capability->capability] = $capability->sum;
$capflags[$capability->id2][$capability->contextlevel][$capability->capability] = true;
}
} else {
$USER->capabilities[$capability->id2][$capability->capability] = $capability->sum;
$capflags[$capability->id2][$capability->contextlevel][$capability->capability] = true;
}
}
}
// now we don't care about the huge array anymore, we can dispose it.
unset($capabilities);
unset($capflags);
if (!empty($otheruserid)) {
return $usercap; // return the array
}
}
/*
* A convenience function to completely load all the capabilities
* for the current user. This is what gets called from login, for example.
*/
function load_all_capabilities() {
global $USER;
if (empty($USER->username)) {
return;
}
load_user_capability(); // Load basic capabilities assigned to this user
if ($USER->username == 'guest') {
load_guest_role(); // All non-guest users get this by default
} else {
load_defaultuser_role(); // All non-guest users get this by default
}
}
/*
* Check all the login enrolment information for the given user object
* by querying the enrolment plugins
*/
function check_enrolment_plugins(&$user) {
global $CFG;
static $inprogress; // To prevent this function being called more than once in an invocation
if (!empty($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
}
/**
* This is a recursive function that checks whether the capability in this
* context, or the parent capabilities are set to prohibit.
*
* At this point, we can probably just use the values already set in the
* session variable, since we are going down the level. Any prohit set in
* parents would already reflect in the session.
*
* @param $capability - capability name
* @param $sum - sum of all capabilities values
* @param $context - the context object
* @param $array - when loading another user caps, their caps are not stored in session but an array
*/
function capability_prohibits($capability, $context, $sum='', $array='') {
global $USER;
if (empty($context->id)) {
return false;
}
if (empty($capability)) {
return false;
}
if ($sum < (CAP_PROHIBIT/2)) {
// If this capability is set to prohibit.
return true;
}
if (!empty($array)) {
if (isset($array[$context->id][$capability])
&& $array[$context->id][$capability] < (CAP_PROHIBIT/2)) {
return true;
}
} else {
// Else if set in session.
if (isset($USER->capabilities[$context->id][$capability])
&& $USER->capabilities[$context->id][$capability] < (CAP_PROHIBIT/2)) {
return true;
}
}
switch ($context->contextlevel) {
case CONTEXT_SYSTEM:
// By now it's a definite an inherit.
return 0;
break;
case CONTEXT_PERSONAL:
$parent = get_context_instance(CONTEXT_SYSTEM);
return capability_prohibits($capability, $parent);
break;
case CONTEXT_USER:
$parent = get_context_instance(CONTEXT_SYSTEM);
return capability_prohibits($capability, $parent);
break;
case CONTEXT_COURSECAT:
// Coursecat -> coursecat or site.
if (!$coursecat = get_record('course_categories','id',$context->instanceid)) {
return false;
}
if (!empty($coursecat->parent)) {
// return parent value if exist.
$parent = get_context_instance(CONTEXT_COURSECAT, $coursecat->parent);
} else {
// Return site value.
$parent = get_context_instance(CONTEXT_SYSTEM);
}
return capability_prohibits($capability, $parent);
break;
case CONTEXT_COURSE:
// 1 to 1 to course cat.
// Find the course cat, and return its value.
if (!$course = get_record('course','id',$context->instanceid)) {
return false;
}
// Yu: Separating site and site course context
if ($course->id == SITEID) {
$parent = get_context_instance(CONTEXT_SYSTEM);
} else {
$parent = get_context_instance(CONTEXT_COURSECAT, $course->category);
}
return capability_prohibits($capability, $parent);
break;
case CONTEXT_GROUP:
// 1 to 1 to course.
if (!$group = get_record('groups','id',$context->instanceid)) {
return false;
}
$parent = get_context_instance(CONTEXT_COURSE, $group->courseid);
return capability_prohibits($capability, $parent);
break;
case CONTEXT_MODULE:
// 1 to 1 to course.
if (!$cm = get_record('course_modules','id',$context->instanceid)) {
return false;
}
$parent = get_context_instance(CONTEXT_COURSE, $cm->course);
return capability_prohibits($capability, $parent);
break;
case CONTEXT_BLOCK:
// 1 to 1 to course.
if (!$block = get_record('block_instance','id',$context->instanceid)) {
return false;
}
$parent = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
return capability_prohibits($capability, $parent);
break;
default:
print_error('unknowncontext');
return false;
}
}
/**
* A print form function. This should either grab all the capabilities from
* files or a central table for that particular module instance, then present
* them in check boxes. Only relevant capabilities should print for known
* context.
* @param $mod - module id of the mod
*/
function print_capabilities($modid=0) {
global $CFG;
$capabilities = array();
if ($modid) {
// We are in a module specific context.
// Get the mod's name.
// Call the function that grabs the file and parse.
$cm = get_record('course_modules', 'id', $modid);
$module = get_record('modules', 'id', $cm->module);
} else {
// Print all capabilities.
foreach ($capabilities as $capability) {
// Prints the check box component.
}
}
}
/**
* Installs the roles system.
* This function runs on a fresh install as well as on an upgrade from the old
* hard-coded student/teacher/admin etc. roles to the new roles system.
*/
function moodle_install_roles() {
global $CFG, $db;
/// Create a system wide context for assignemnt.
$systemcontext = $context = get_context_instance(CONTEXT_SYSTEM);
/// Create default/legacy roles and capabilities.
/// (1 legacy capability per legacy role at system level).
$adminrole = create_role(addslashes(get_string('administrator')), 'admin',
addslashes(get_string('administratordescription')), 'moodle/legacy:admin');
$coursecreatorrole = create_role(addslashes(get_string('coursecreators')), 'coursecreator',
addslashes(get_string('coursecreatorsdescription')), 'moodle/legacy:coursecreator');
$editteacherrole = create_role(addslashes(get_string('defaultcourseteacher')), 'editingteacher',
addslashes(get_string('defaultcourseteacherdescription')), 'moodle/legacy:editingteacher');
$noneditteacherrole = create_role(addslashes(get_string('noneditingteacher')), 'teacher',
addslashes(get_string('noneditingteacherdescription')), 'moodle/legacy:teacher');
$studentrole = create_role(addslashes(get_string('defaultcoursestudent')), 'student',
addslashes(get_string('defaultcoursestudentdescription')), 'moodle/legacy:student');
$guestrole = create_role(addslashes(get_string('guest')), 'guest',
addslashes(get_string('guestdescription')), 'moodle/legacy:guest');
/// Now is the correct moment to install capabilities - after creation of legacy roles, but before assigning of roles
if (!assign_capability('moodle/site:doanything', CAP_ALLOW, $adminrole, $systemcontext->id)) {
error('Could not assign moodle/site:doanything to the admin role');
}
if (!update_capabilities()) {
error('Had trouble upgrading the core capabilities for the Roles System');
}
/// Look inside user_admin, user_creator, user_teachers, user_students and
/// assign above new roles. If a user has both teacher and student role,
/// only teacher role is assigned. The assignment should be system level.
$dbtables = $db->MetaTables('TABLES');
/// Set up the progress bar
$usertables = array('user_admins', 'user_coursecreators', 'user_teachers', 'user_students');
$totalcount = $progresscount = 0;
foreach ($usertables as $usertable) {
if (in_array($CFG->prefix.$usertable, $dbtables)) {
$totalcount += count_records($usertable);
}
}
print_progress(0, $totalcount, 5, 1, 'Processing role assignments');
/// Upgrade the admins.
/// Sort using id ASC, first one is primary admin.
if (in_array($CFG->prefix.'user_admins', $dbtables)) {
if ($rs = get_recordset_sql('SELECT * from '.$CFG->prefix.'user_admins ORDER BY ID ASC')) {
while (! $rs->EOF) {
$admin = $rs->FetchObj();
role_assign($adminrole, $admin->userid, 0, $systemcontext->id);
$progresscount++;
print_progress($progresscount, $totalcount, 5, 1, 'Processing role assignments');
$rs->MoveNext();
}
}
} else {
// This is a fresh install.
}
/// Upgrade course creators.
if (in_array($CFG->prefix.'user_coursecreators', $dbtables)) {
if ($rs = get_recordset('user_coursecreators')) {
while (! $rs->EOF) {
$coursecreator = $rs->FetchObj();
role_assign($coursecreatorrole, $coursecreator->userid, 0, $systemcontext->id);
$progresscount++;
print_progress($progresscount, $totalcount, 5, 1, 'Processing role assignments');
$rs->MoveNext();
}
}
}
/// Upgrade editting teachers and non-editting teachers.
if (in_array($CFG->prefix.'user_teachers', $dbtables)) {
if ($rs = get_recordset('user_teachers')) {
while (! $rs->EOF) {
$teacher = $rs->FetchObj();
// removed code here to ignore site level assignments
// since the contexts are separated now
// populate the user_lastaccess table
$access = new object();
$access->timeaccess = $teacher->timeaccess;
$access->userid = $teacher->userid;
$access->courseid = $teacher->course;
insert_record('user_lastaccess', $access);
// assign the default student role
$coursecontext = get_context_instance(CONTEXT_COURSE, $teacher->course); // needs cache
if ($teacher->editall) { // editting teacher
role_assign($editteacherrole, $teacher->userid, 0, $coursecontext->id);
} else {
role_assign($noneditteacherrole, $teacher->userid, 0, $coursecontext->id);
}
$progresscount++;
print_progress($progresscount, $totalcount, 5, 1, 'Processing role assignments');
$rs->MoveNext();
}
}
}
/// Upgrade students.
if (in_array($CFG->prefix.'user_students', $dbtables)) {
if ($rs = get_recordset('user_students')) {
while (! $rs->EOF) {
$student = $rs->FetchObj();
// populate the user_lastaccess table
$access = new object;
$access->timeaccess = $student->timeaccess;
$access->userid = $student->userid;
$access->courseid = $student->course;
insert_record('user_lastaccess', $access);
// assign the default student role
$coursecontext = get_context_instance(CONTEXT_COURSE, $student->course);
role_assign($studentrole, $student->userid, 0, $coursecontext->id);
$progresscount++;
print_progress($progresscount, $totalcount, 5, 1, 'Processing role assignments');
$rs->MoveNext();
}
}
}
/// Upgrade guest (only 1 entry).
if ($guestuser = get_record('user', 'username', 'guest')) {
role_assign($guestrole, $guestuser->id, 0, $systemcontext->id);
}
print_progress($totalcount, $totalcount, 5, 1, 'Processing role assignments');
/// Insert the correct records for legacy roles
allow_assign($adminrole, $adminrole);
allow_assign($adminrole, $coursecreatorrole);
allow_assign($adminrole, $noneditteacherrole);
allow_assign($adminrole, $editteacherrole);
allow_assign($adminrole, $studentrole);
allow_assign($adminrole, $guestrole);
allow_assign($coursecreatorrole, $noneditteacherrole);
allow_assign($coursecreatorrole, $editteacherrole);
allow_assign($coursecreatorrole, $studentrole);
allow_assign($coursecreatorrole, $guestrole);
allow_assign($editteacherrole, $noneditteacherrole);
allow_assign($editteacherrole, $studentrole);
allow_assign($editteacherrole, $guestrole);
/// Set up default permissions for overrides
allow_override($adminrole, $adminrole);
allow_override($adminrole, $coursecreatorrole);
allow_override($adminrole, $noneditteacherrole);
allow_override($adminrole, $editteacherrole);
allow_override($adminrole, $studentrole);
allow_override($adminrole, $guestrole);
/// Delete the old user tables when we are done
drop_table(new XMLDBTable('user_students'));
drop_table(new XMLDBTable('user_teachers'));
drop_table(new XMLDBTable('user_coursecreators'));
drop_table(new XMLDBTable('user_admins'));
}
/**
* Assign the defaults found in this capabality definition to roles that have
* the corresponding legacy capabilities assigned to them.
* @param $legacyperms - an array in the format (example):
* 'guest' => CAP_PREVENT,
* 'student' => CAP_ALLOW,
* 'teacher' => CAP_ALLOW,
* 'editingteacher' => CAP_ALLOW,
* 'coursecreator' => CAP_ALLOW,
* 'admin' => CAP_ALLOW
* @return boolean - success or failure.
*/
function assign_legacy_capabilities($capability, $legacyperms) {
foreach ($legacyperms as $type => $perm) {
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
// The legacy capabilities are:
// 'moodle/legacy:guest'
// 'moodle/legacy:student'
// 'moodle/legacy:teacher'
// 'moodle/legacy:editingteacher'
// 'moodle/legacy:coursecreator'
// 'moodle/legacy:admin'
if ($roles = get_roles_with_capability('moodle/legacy:'.$type, CAP_ALLOW)) {
foreach ($roles as $role) {
// Assign a site level capability.
if (!assign_capability($capability, $perm, $role->id, $systemcontext->id)) {
return false;
}
}
}
}
return true;
}
/**
* Checks to see if a capability is a legacy capability.
* @param $capabilityname
* @return boolean
*/
function islegacy($capabilityname) {
if (strstr($capabilityname, 'legacy') === false) {
return false;
} else {
return true;
}
}
/**********************************
* Context Manipulation functions *
**********************************/
/**
* Create a new context record for use by all roles-related stuff
* @param $level
* @param $instanceid
*
* @return object newly created context (or existing one with a debug warning)
*/
function create_context($contextlevel, $instanceid) {
if (!$context = get_record('context','contextlevel',$contextlevel,'instanceid',$instanceid)) {
if (!validate_context($contextlevel, $instanceid)) {
debugging('Error: Invalid context creation request for level "'.s($contextlevel).'", instance "'.s($instanceid).'".');
return NULL;
}
$context = new object();
$context->contextlevel = $contextlevel;
$context->instanceid = $instanceid;
if ($id = insert_record('context',$context)) {
return get_record('context','id',$id);
} else {
debugging('Error: could not insert new context level "'.s($contextlevel).'", instance "'.s($instanceid).'".');
return NULL;
}
} else {
debugging('Warning: Context id "'.s($context->id).'" not created, because it already exists.');
return $context;
}
}
/**
* Create a new context record for use by all roles-related stuff
* @param $level
* @param $instanceid
*
* @return true if properly deleted
*/
function delete_context($contextlevel, $instanceid) {
if ($context = get_context_instance($contextlevel, $instanceid)) {
return delete_records('context', 'id', $context->id) &&
delete_records('role_assignments', 'contextid', $context->id) &&
delete_records('role_capabilities', 'contextid', $context->id);
}
return true;
}
/**
* Validate that object with instanceid really exists in given context level.
*
* return if instanceid object exists
*/
function validate_context($contextlevel, $instanceid) {
switch ($contextlevel) {
case CONTEXT_SYSTEM:
return ($instanceid == SITEID);
case CONTEXT_PERSONAL:
return (boolean)count_records('user', 'id', $instanceid);
case CONTEXT_USER:
return (boolean)count_records('user', 'id', $instanceid);
case CONTEXT_COURSECAT:
if ($instanceid == 0) {
return true; // site course category
}
return (boolean)count_records('course_categories', 'id', $instanceid);
case CONTEXT_COURSE:
return (boolean)count_records('course', 'id', $instanceid);
case CONTEXT_GROUP:
return (boolean)count_records('groups', 'id', $instanceid);
case CONTEXT_MODULE:
return (boolean)count_records('course_modules', 'id', $instanceid);
case CONTEXT_BLOCK:
return (boolean)count_records('block_instance', 'id', $instanceid);
default:
return false;
}
}
/**
* Get the context instance as an object. This function will create the
* context instance if it does not exist yet.
* @param $level
* @param $instance
*/
function get_context_instance($contextlevel=NULL, $instance=SITEID) {
global $context_cache, $context_cache_id, $CONTEXT;
static $allowed_contexts = array(CONTEXT_SYSTEM, CONTEXT_PERSONAL, CONTEXT_USER, CONTEXT_COURSECAT, CONTEXT_COURSE, CONTEXT_GROUP, CONTEXT_MODULE, CONTEXT_BLOCK);
// This is really a systen context
// Yu: Separating site and site course context
/*
if ($contextlevel == CONTEXT_COURSE && $instance == SITEID) {
$contextlevel = CONTEXT_SYSTEM;
}*/
/// If no level is supplied then return the current global context if there is one
if (empty($contextlevel)) {
if (empty($CONTEXT)) {
//fatal error, code must be fixed
error("Error: get_context_instance() called without a context");
} else {
return $CONTEXT;
}
}
/// check allowed context levels
if (!in_array($contextlevel, $allowed_contexts)) {
// fatal error, code must be fixed - probably typo or switched parameters
error('Error: get_context_instance() called with incorrect context level "'.s($contextlevel).'"');
}
/// Check the cache
if (isset($context_cache[$contextlevel][$instance])) { // Already cached
return $context_cache[$contextlevel][$instance];
}
/// Get it from the database, or create it
if (!$context = get_record('context', 'contextlevel', $contextlevel, 'instanceid', $instance)) {
create_context($contextlevel, $instance);
$context = get_record('context', 'contextlevel', $contextlevel, 'instanceid', $instance);
}
/// Only add to cache if context isn't empty.
if (!empty($context)) {
$context_cache[$contextlevel][$instance] = $context; // Cache it for later
$context_cache_id[$context->id] = $context; // Cache it for later
}
return $context;
}
/**
* Get a context instance as an object, from a given id.
* @param $id
*/
function get_context_instance_by_id($id) {
global $context_cache, $context_cache_id;
if (isset($context_cache_id[$id])) { // Already cached
return $context_cache_id[$id];
}
if ($context = get_record('context', 'id', $id)) { // Update the cache and return
$context_cache[$context->contextlevel][$context->instanceid] = $context;
$context_cache_id[$context->id] = $context;
return $context;
}
return false;
}
/**
* Get the local override (if any) for a given capability in a role in a context
* @param $roleid
* @param $contextid
* @param $capability
*/
function get_local_override($roleid, $contextid, $capability) {
return get_record('role_capabilities', 'roleid', $roleid, 'capability', $capability, 'contextid', $contextid);
}
/************************************
* DB TABLE RELATED FUNCTIONS *
************************************/
/**
* function that creates a role
* @param name - role name
* @param shortname - role short name
* @param description - role description
* @param legacy - optional legacy capability
* @return id or false
*/
function create_role($name, $shortname, $description, $legacy='') {
// check for duplicate role name
if ($role = get_record('role','name', $name)) {
error('there is already a role with this name!');
}
if ($role = get_record('role','shortname', $shortname)) {
error('there is already a role with this shortname!');
}
$role = new object();
$role->name = $name;
$role->shortname = $shortname;
$role->description = $description;
//find free sortorder number
$role->sortorder = count_records('role');
while (get_record('role','sortorder', $role->sortorder)) {
$role->sortorder += 1;
}
if (!$context = get_context_instance(CONTEXT_SYSTEM)) {
return false;
}
if ($id = insert_record('role', $role)) {
if ($legacy) {
assign_capability($legacy, CAP_ALLOW, $id, $context->id);
}
/// By default, users with role:manage at site level
/// should be able to assign users to this new role, and override this new role's capabilities
// find all admin roles
if ($adminroles = get_roles_with_capability('moodle/role:manage', CAP_ALLOW, $context)) {
// foreach admin role
foreach ($adminroles as $arole) {
// write allow_assign and allow_overrid
allow_assign($arole->id, $id);
allow_override($arole->id, $id);
}
}
return $id;
} else {
return false;
}
}
/**
* function that deletes a role and cleanups up after it
* @param roleid - id of role to delete
* @return success
*/
function delete_role($roleid) {
$success = true;
// first unssign all users
if (!role_unassign($roleid)) {
debugging("Error while unassigning all users from role with ID $roleid!");
$success = false;
}
// cleanup all references to this role, ignore errors
if ($success) {
delete_records('role_capabilities', 'roleid', $roleid);
delete_records('role_allow_assign', 'roleid', $roleid);
delete_records('role_allow_assign', 'allowassign', $roleid);
delete_records('role_allow_override', 'roleid', $roleid);
delete_records('role_allow_override', 'allowoverride', $roleid);
delete_records('role_names', 'roleid', $roleid);
}
// finally delete the role itself
if ($success and !delete_records('role', 'id', $roleid)) {
debugging("Could not delete role record with ID $roleid!");
$success = false;
}
return $success;
}
/**
* Function to write context specific overrides, or default capabilities.
* @param module - string name
* @param capability - string name
* @param contextid - context id
* @param roleid - role id
* @param permission - int 1,-1 or -1000
* should not be writing if permission is 0
*/
function assign_capability($capability, $permission, $roleid, $contextid, $overwrite=false) {
global $USER;
if (empty($permission) || $permission == CAP_INHERIT) { // if permission is not set
unassign_capability($capability, $roleid, $contextid);
return true;
}
$existing = get_record('role_capabilities', '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;
return update_record('role_capabilities', $cap);
} else {
return insert_record('role_capabilities', $cap);
}
}
/**
* Unassign a capability from a role.
* @param $roleid - the role id
* @param $capability - the name of the capability
* @return boolean - success or failure
*/
function unassign_capability($capability, $roleid, $contextid=NULL) {
if (isset($contextid)) {
$status = delete_records('role_capabilities', 'capability', $capability,
'roleid', $roleid, 'contextid', $contextid);
} else {
$status = delete_records('role_capabilities', 'capability', $capability,
'roleid', $roleid);
}
return $status;
}
/**
* 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.
* @param $capability - capability name (string)
* @param $permission - optional, the permission defined for this capability
* either CAP_ALLOW, CAP_PREVENT or CAP_PROHIBIT
* @return array or role objects
*/
function get_roles_with_capability($capability, $permission=NULL, $context='') {
global $CFG;
if ($context) {
if ($contexts = get_parent_contexts($context)) {
$listofcontexts = '('.implode(',', $contexts).')';
} else {
$sitecontext = get_context_instance(CONTEXT_SYSTEM);
$listofcontexts = '('.$sitecontext->id.')'; // must be site
}
$contextstr = "AND (rc.contextid = '$context->id' OR rc.contextid IN $listofcontexts)";
} else {
$contextstr = '';
}
$selectroles = "SELECT r.*
FROM {$CFG->prefix}role r,
{$CFG->prefix}role_capabilities rc
WHERE rc.capability = '$capability'
AND rc.roleid = r.id $contextstr";
if (isset($permission)) {
$selectroles .= " AND rc.permission = '$permission'";
}
return get_records_sql($selectroles);
}
/**
* This function makes a role-assignment (a role for a user or group in a particular context)
* @param $roleid - the role of the id
* @param $userid - userid
* @param $groupid - group id
* @param $contextid - id of the context
* @param $timestart - time this assignment becomes effective
* @param $timeend - time this assignemnt ceases to be effective
* @uses $USER
* @return id - new id of the assigment
*/
function role_assign($roleid, $userid, $groupid, $contextid, $timestart=0, $timeend=0, $hidden=0, $enrol='manual') {
global $USER, $CFG;
debugging("Assign roleid $roleid userid $userid contextid $contextid", DEBUG_DEVELOPER);
/// Do some data validation
if (empty($roleid)) {
debugging('Role ID not provided');
return false;
}
if (empty($userid) && empty($groupid)) {
debugging('Either userid or groupid must be provided');
return false;
}
if ($userid && !record_exists('user', 'id', $userid)) {
debugging('User ID '.intval($userid).' does not exist!');
return false;
}
if ($groupid && !record_exists('groups', 'id', $groupid)) {
debugging('Group ID '.intval($groupid).' 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 > $timeend)) {
debugging('The end time can not be earlier than the start time');
return false;
}
/// Check for existing entry
if ($userid) {
$ra = get_record('role_assignments', 'roleid', $roleid, 'contextid', $context->id, 'userid', $userid);
} else {
$ra = get_record('role_assignments', 'roleid', $roleid, 'contextid', $context->id, 'groupid', $groupid);
}
$newra = new object;
if (empty($ra)) { // Create a new entry
$newra->roleid = $roleid;
$newra->contextid = $context->id;
$newra->userid = $userid;
$newra->hidden = $hidden;
$newra->enrol = $enrol;
$newra->timestart = $timestart;
$newra->timeend = $timeend;
$newra->timemodified = time();
$newra->modifierid = empty($USER->id) ? 0 : $USER->id;
$success = insert_record('role_assignments', $newra);
} else { // We already have one, just update it
$newra->id = $ra->id;
$newra->hidden = $hidden;
$newra->enrol = $enrol;
$newra->timestart = $timestart;
$newra->timeend = $timeend;
$newra->timemodified = time();
$newra->modifierid = empty($USER->id) ? 0 : $USER->id;
$success = update_record('role_assignments', $newra);
}
if ($success) { /// Role was assigned, so do some other things
/// If the user is the current user, then reload the capabilities too.
if (!empty($USER->id) && $USER->id == $userid) {
load_all_capabilities();
}
/// Ask all the modules if anything needs to be done for this user
if ($mods = get_list_of_plugins('mod')) {
foreach ($mods as $mod) {
include_once($CFG->dirroot.'/mod/'.$mod.'/lib.php');
$functionname = $mod.'_role_assign';
if (function_exists($functionname)) {
$functionname($userid, $context);
}
}
}
/// Make sure they have an entry in user_lastaccess for courses they can access
// role_add_lastaccess_entries($userid, $context);
}
/// now handle metacourse role assignments if in course context
if ($success and $context->contextlevel == CONTEXT_COURSE) {
if ($parents = get_records('course_meta', 'child_course', $context->instanceid)) {
foreach ($parents as $parent) {
sync_metacourse($parent->parent_course);
}
}
}
return $success;
}
/**
* Deletes one or more role assignments. You must specify at least one parameter.
* @param $roleid
* @param $userid
* @param $groupid
* @param $contextid
* @return boolean - success or failure
*/
function role_unassign($roleid=0, $userid=0, $groupid=0, $contextid=0) {
global $USER, $CFG;
$success = true;
$args = array('roleid', 'userid', 'groupid', 'contextid');
$select = array();
foreach ($args as $arg) {
if ($$arg) {
$select[] = $arg.' = '.$$arg;
}
}
if ($select) {
if ($ras = get_records_select('role_assignments', implode(' AND ', $select))) {
$mods = get_list_of_plugins('mod');
foreach($ras as $ra) {
/// infinite loop protection when deleting recursively
if (!$ra = get_record('role_assignments', 'id', $ra->id)) {
continue;
}
$success = delete_records('role_assignments', 'id', $ra->id) and $success;
/// If the user is the current user, then reload the capabilities too.
if (!empty($USER->id) && $USER->id == $ra->userid) {
load_all_capabilities();
}
$context = get_record('context', 'id', $ra->contextid);
/// Ask all the modules if anything needs to be done for this user
foreach ($mods as $mod) {
include_once($CFG->dirroot.'/mod/'.$mod.'/lib.php');
$functionname = $mod.'_role_unassign';
if (function_exists($functionname)) {
$functionname($ra->userid, $context); // watch out, $context might be NULL if something goes wrong
}
}
/// now handle metacourse role unassigment and removing from goups if in course context
if (!empty($context) and $context->contextlevel == CONTEXT_COURSE) {
//remove from groups when user has no role
$roles = get_user_roles($context, $ra->userid, true);
if (empty($roles)) {
if ($groups = get_groups($context->instanceid, $ra->userid)) {
foreach ($groups as $group) {
delete_records('groups_members', 'groupid', $group->id, 'userid', $ra->userid);
}
}
}
//unassign roles in metacourses if needed
if ($parents = get_records('course_meta', 'child_course', $context->instanceid)) {
foreach ($parents as $parent) {
sync_metacourse($parent->parent_course);
}
}
}
}
}
}
return $success;
}
/*
* 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 $enrol - the plugin used to do this enrolment
*/
function enrol_into_course($course, $user, $enrol) {
if ($course->enrolperiod) {
$timestart = time();
$timeend = time() + $course->enrolperiod;
} else {
$timestart = $timeend = 0;
}
if ($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, $enrol)) {
return false;
}
email_welcome_message_to_user($course, $user);
add_to_log($course->id, 'course', 'enrol', 'view.php?id='.$course->id, $user->id);
return true;
}
return false;
}
/**
* Add last access times to user_lastaccess as required
* @param $userid
* @param $context
* @return boolean - success or failure
*/
function role_add_lastaccess_entries($userid, $context) {
global $USER, $CFG;
if (empty($context->contextlevel)) {
return false;
}
$lastaccess = new object; // Reusable object below
$lastaccess->userid = $userid;
$lastaccess->timeaccess = 0;
switch ($context->contextlevel) {
case CONTEXT_SYSTEM: // For the whole site
if ($courses = get_record('course')) {
foreach ($courses as $course) {
$lastaccess->courseid = $course->id;
role_set_lastaccess($lastaccess);
}
}
break;
case CONTEXT_CATEGORY: // For a whole category
if ($courses = get_record('course', 'category', $context->instanceid)) {
foreach ($courses as $course) {
$lastaccess->courseid = $course->id;
role_set_lastaccess($lastaccess);
}
}
if ($categories = get_record('course_categories', 'parent', $context->instanceid)) {
foreach ($categories as $category) {
$subcontext = get_context_instance(CONTEXT_CATEGORY, $category->id);
role_add_lastaccess_entries($userid, $subcontext);
}
}
break;
case CONTEXT_COURSE: // For a whole course
if ($course = get_record('course', 'id', $context->instanceid)) {
$lastaccess->courseid = $course->id;
role_set_lastaccess($lastaccess);
}
break;
}
}
/**
* Delete last access times from user_lastaccess as required
* @param $userid
* @param $context
* @return boolean - success or failure
*/
function role_remove_lastaccess_entries($userid, $context) {
global $USER, $CFG;
}
/**
* Loads the capability definitions for the component (from file). If no
* capabilities are defined for the component, we simply return an empty array.
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
* @return array of capabilities
*/
function load_capability_def($component) {
global $CFG;
if ($component == 'moodle') {
$defpath = $CFG->libdir.'/db/access.php';
$varprefix = 'moodle';
} else {
$compparts = explode('/', $component);
if ($compparts[0] == 'block') {
// Blocks are an exception. Blocks directory is 'blocks', and not
// 'block'. So we need to jump through hoops.
$defpath = $CFG->dirroot.'/'.$compparts[0].
's/'.$compparts[1].'/db/access.php';
$varprefix = $compparts[0].'_'.$compparts[1];
} else {
$defpath = $CFG->dirroot.'/'.$component.'/db/access.php';
$varprefix = str_replace('/', '_', $component);
}
}
$capabilities = array();
if (file_exists($defpath)) {
require_once($defpath);
$capabilities = ${$varprefix.'_capabilities'};
}
return $capabilities;
}
/**
* Gets the capabilities that have been cached in the database for this
* component.
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
* @return array of capabilities
*/
function get_cached_capabilities($component='moodle') {
if ($component == 'moodle') {
$storedcaps = get_records_select('capabilities',
"name LIKE 'moodle/%:%'");
} else {
$storedcaps = get_records_select('capabilities',
"name LIKE '$component:%'");
}
return $storedcaps;
}
/**
* 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.
*
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
* @return boolean
*/
function update_capabilities($component='moodle') {
$storedcaps = array();
$filecaps = load_capability_def($component);
$cachedcaps = get_cached_capabilities($component);
if ($cachedcaps) {
foreach ($cachedcaps as $cachedcap) {
array_push($storedcaps, $cachedcap->name);
// update risk bitmasks in existing capabilities if needed
if (array_key_exists($cachedcap->name, $filecaps)) {
if (!array_key_exists('riskbitmask', $filecaps[$cachedcap->name])) {
$filecaps[$cachedcap->name]['riskbitmask'] = 0; // no risk if not specified
}
if ($cachedcap->riskbitmask != $filecaps[$cachedcap->name]['riskbitmask']) {
$updatecap = new object;
$updatecap->id = $cachedcap->id;
$updatecap->riskbitmask = $filecaps[$cachedcap->name]['riskbitmask'];
if (!update_record('capabilities', $updatecap)) {
return false;
}
}
}
}
}
// 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'];
if (!insert_record('capabilities', $capability, false, 'id')) {
return false;
}
// Do we need to assign the new capabilities to roles that have the
// legacy capabilities moodle/legacy:* as well?
if (isset($capdef['legacy']) && is_array($capdef['legacy']) &&
!assign_legacy_capabilities($capname, $capdef['legacy'])) {
notify('Could not assign legacy capabilities for '.$capname);
}
}
// 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);
return true;
}
/**
* Deletes cached capabilities that are no longer needed by the component.
* Also unassigns these capabilities from any roles that have them.
* @param $component - examples: 'moodle', 'mod/forum', 'block/quiz_results'
* @param $newcapdef - array of the new capability definitions that will be
* compared with the cached capabilities
* @return int - number of deprecated capabilities that have been removed
*/
function capabilities_cleanup($component, $newcapdef=NULL) {
$removedcount = 0;
if ($cachedcaps = get_cached_capabilities($component)) {
foreach ($cachedcaps as $cachedcap) {
if (empty($newcapdef) ||
array_key_exists($cachedcap->name, $newcapdef) === false) {
// Remove from capabilities cache.
if (!delete_records('capabilities', 'name', $cachedcap->name)) {
error('Could not delete deprecated capability '.$cachedcap->name);
} else {
$removedcount++;
}
// Delete from roles.
if($roles = get_roles_with_capability($cachedcap->name)) {
foreach($roles as $role) {
if (!unassign_capability($cachedcap->name, $role->id)) {
error('Could not unassign deprecated capability '.
$cachedcap->name.' from role '.$role->name);
}
}
}
} // End if.
}
}
return $removedcount;
}
/****************
* UI FUNCTIONS *
****************/
/**
* prints human readable context identifier.
*/
function print_context_name($context) {
$name = '';
switch ($context->contextlevel) {
case CONTEXT_SYSTEM: // by now it's a definite an inherit
$name = get_string('site');
break;
case CONTEXT_PERSONAL:
$name = get_string('personal');
break;
case CONTEXT_USER:
if ($user = get_record('user', 'id', $context->instanceid)) {
$name = get_string('user').': '.fullname($user);
}
break;
case CONTEXT_COURSECAT: // Coursecat -> coursecat or site
if ($category = get_record('course_categories', 'id', $context->instanceid)) {
$name = get_string('category').': '.$category->name;
}
break;
case CONTEXT_COURSE: // 1 to 1 to course cat
if ($course = get_record('course', 'id', $context->instanceid)) {
$name = get_string('course').': '.$course->fullname;
}
break;
case CONTEXT_GROUP: // 1 to 1 to course
if ($group = get_record('groups', 'id', $context->instanceid)) {
$name = get_string('group').': '.$group->name;
}
break;
case CONTEXT_MODULE: // 1 to 1 to course
if ($cm = get_record('course_modules','id',$context->instanceid)) {
if ($module = get_record('modules','id',$cm->module)) {
if ($mod = get_record($module->name, 'id', $cm->instance)) {
$name = get_string('activitymodule').': '.$mod->name;
}
}
}
break;
case CONTEXT_BLOCK: // 1 to 1 to course
if ($blockinstance = get_record('block_instance','id',$context->instanceid)) {
if ($block = get_record('block','id',$blockinstance->blockid)) {
global $CFG;
require_once("$CFG->dirroot/blocks/moodleblock.class.php");
require_once("$CFG->dirroot/blocks/$block->name/block_$block->name.php");
$blockname = "block_$block->name";
if ($blockobject = new $blockname()) {
$name = $blockobject->title.' ('.get_string('block').')';
}
}
}
break;
default:
error ('This is an unknown context!');
return false;
}
return $name;
}
/**
* Extracts the relevant capabilities given a contextid.
* All case based, example an instance of forum context.
* Will fetch all forum related capabilities, while course contexts
* Will fetch all capabilities
* @param object context
* @return array();
*
* capabilities
* `name` varchar(150) NOT NULL,
* `captype` varchar(50) NOT NULL,
* `contextlevel` int(10) NOT NULL,
* `component` varchar(100) NOT NULL,
*/
function fetch_context_capabilities($context) {
global $CFG;
$sort = 'ORDER BY contextlevel,component,id'; // To group them sensibly for display
switch ($context->contextlevel) {
case CONTEXT_SYSTEM: // all
$SQL = "select * from {$CFG->prefix}capabilities";
break;
case CONTEXT_PERSONAL:
$SQL = "select * from {$CFG->prefix}capabilities where contextlevel = ".CONTEXT_PERSONAL;
break;
case CONTEXT_USER:
$SQL = "SELECT *
FROM {$CFG->prefix}capabilities
WHERE contextlevel = ".CONTEXT_USER;
break;
case CONTEXT_COURSECAT: // all
$SQL = "select * from {$CFG->prefix}capabilities";
break;
case CONTEXT_COURSE: // all
$SQL = "select * from {$CFG->prefix}capabilities";
break;
case CONTEXT_GROUP: // group caps
break;
case CONTEXT_MODULE: // mod caps
$cm = get_record('course_modules', 'id', $context->instanceid);
$module = get_record('modules', 'id', $cm->module);
$SQL = "select * from {$CFG->prefix}capabilities where contextlevel = ".CONTEXT_MODULE."
and component = 'mod/$module->name'";
break;
case CONTEXT_BLOCK: // block caps
$cb = get_record('block_instance', 'id', $context->instanceid);
$block = get_record('block', 'id', $cb->blockid);
$SQL = "select * from {$CFG->prefix}capabilities where contextlevel = ".CONTEXT_BLOCK."
and component = 'block/$block->name'";
break;
default:
return false;
}
if (!$records = get_records_sql($SQL.' '.$sort)) {
$records = array();
}
/// the rest of code is a bit hacky, think twice before modifying it :-(
// special sorting of core system capabiltites and enrollments
if (in_array($context->contextlevel, array(CONTEXT_SYSTEM, CONTEXT_COURSECAT, CONTEXT_COURSE))) {
$first = array();
foreach ($records as $key=>$record) {
if (preg_match('|^moodle/|', $record->name) and $record->contextlevel == CONTEXT_SYSTEM) {
$first[$key] = $record;
unset($records[$key]);
} else if (count($first)){
break;
}
}
if (count($first)) {
$records = $first + $records; // merge the two arrays keeping the keys
}
} else {
$contextindependentcaps = fetch_context_independent_capabilities();
$records = array_merge($contextindependentcaps, $records);
}
return $records;
}
/**
* Gets the context-independent capabilities that should be overrridable in
* any context.
* @return array of capability records from the capabilities table.
*/
function fetch_context_independent_capabilities() {
//only CONTEXT_SYSTEM capabilities here or it will break the hack in fetch_context_capabilities()
$contextindependentcaps = array(
'moodle/site:accessallgroups'
);
$records = array();
foreach ($contextindependentcaps as $capname) {
$record = get_record('capabilities', 'name', $capname);
array_push($records, $record);
}
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.
* @param obj $context
* @param int $roleid
* @param bool self - if set to true, resolve till this level, else stop at immediate parent level
* @return array
*/
function role_context_capabilities($roleid, $context, $cap='') {
global $CFG;
$contexts = get_parent_contexts($context);
$contexts[] = $context->id;
$contexts = '('.implode(',', $contexts).')';
if ($cap) {
$search = " AND rc.capability = '$cap' ";
} else {
$search = '';
}
$SQL = "SELECT rc.*
FROM {$CFG->prefix}role_capabilities rc,
{$CFG->prefix}context c
WHERE rc.contextid in $contexts
AND rc.roleid = $roleid
AND rc.contextid = c.id $search
ORDER BY c.contextlevel DESC,
rc.capability DESC";
$capabilities = array();
if ($records = get_records_sql($SQL)) {
// We are traversing via reverse order.
foreach ($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 $context
* @return array()
*/
function get_parent_contexts($context) {
switch ($context->contextlevel) {
case CONTEXT_SYSTEM: // no parent
return array();
break;
case CONTEXT_PERSONAL:
if (!$parent = get_context_instance(CONTEXT_SYSTEM)) {
return array();
} else {
return array($parent->id);
}
break;
case CONTEXT_USER:
if (!$parent = get_context_instance(CONTEXT_SYSTEM)) {
return array();
} else {
return array($parent->id);
}
break;
case CONTEXT_COURSECAT: // Coursecat -> coursecat or site
if (!$coursecat = get_record('course_categories','id',$context->instanceid)) {
return array();
}
if (!empty($coursecat->parent)) { // return parent value if exist
$parent = get_context_instance(CONTEXT_COURSECAT, $coursecat->parent);
return array_merge(array($parent->id), get_parent_contexts($parent));
} else { // else return site value
$parent = get_context_instance(CONTEXT_SYSTEM);
return array($parent->id);
}
break;
case CONTEXT_COURSE: // 1 to 1 to course cat
if (!$course = get_record('course','id',$context->instanceid)) {
return array();
}
if ($course->id != SITEID) {
$parent = get_context_instance(CONTEXT_COURSECAT, $course->category);
return array_merge(array($parent->id), get_parent_contexts($parent));
} else {
// Yu: Separating site and site course context
$parent = get_context_instance(CONTEXT_SYSTEM);
return array($parent->id);
}
break;
case CONTEXT_GROUP: // 1 to 1 to course
if (!$group = get_record('groups','id',$context->instanceid)) {
return array();
}
if ($parent = get_context_instance(CONTEXT_COURSE, $group->courseid)) {
return array_merge(array($parent->id), get_parent_contexts($parent));
} else {
return array();
}
break;
case CONTEXT_MODULE: // 1 to 1 to course
if (!$cm = get_record('course_modules','id',$context->instanceid)) {
return array();
}
if ($parent = get_context_instance(CONTEXT_COURSE, $cm->course)) {
return array_merge(array($parent->id), get_parent_contexts($parent));
} else {
return array();
}
break;
case CONTEXT_BLOCK: // 1 to 1 to course
if (!$block = get_record('block_instance','id',$context->instanceid)) {
return array();
}
if ($parent = get_context_instance(CONTEXT_COURSE, $block->pageid)) {
return array_merge(array($parent->id), get_parent_contexts($parent));
} else {
return array();
}
break;
default:
error('This is an unknown context!');
return false;
}
}
/**
* 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);
}
}
/**
* This function gets the capability of a role in a given context.
* It is needed when printing override forms.
* @param int $contextid
* @param string $capability
* @param array $capabilities - array loaded using role_context_capabilities
* @return int (allow, prevent, prohibit, inherit)
*/
function get_role_context_capability($contextid, $capability, $capabilities) {
if (isset($capabilities[$contextid][$capability])) {
return $capabilities[$contextid][$capability];
}
else {
return false;
}
}
/**
* Returns the human-readable, translated version of the capability.
* Basically a big switch statement.
* @param $capabilityname - e.g. mod/choice:readresponses
*/
function get_capability_string($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 'mod':
$string = get_string($stringname, $componentname);
break;
case 'block':
$string = get_string($stringname, 'block_'.$componentname);
break;
case 'moodle':
$string = get_string($stringname, 'role');
break;
case 'enrol':
$string = get_string($stringname, 'enrol_'.$componentname);
break;
default:
$string = get_string($stringname);
break;
}
return $string;
}
/**
* This gets the mod/block/course/core etc strings.
* @param $component
* @param $contextlevel
*/
function get_component_string($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('blockname', $langname);
} else {
$string = get_string('coresystem');
}
break;
case CONTEXT_PERSONAL:
$string = get_string('personal');
break;
case CONTEXT_USER:
$string = get_string('users');
break;
case CONTEXT_COURSECAT:
$string = get_string('categories');
break;
case CONTEXT_COURSE:
$string = get_string('course');
break;
case CONTEXT_GROUP:
$string = get_string('group');
break;
case CONTEXT_MODULE:
$string = get_string('modulename', basename($component));
break;
case CONTEXT_BLOCK:
$string = get_string('blockname', 'block_'.$component.'.php');
break;
default:
error ('This is an unknown context!');
return false;
}
return $string;
}
/**
* Gets the list of roles assigned to this context and up (parents)
* @param object $context
* @param view - set to true when roles are pulled for display only
* this is so that we can filter roles with no visible
* assignment, for example, you might want to "hide" all
* course creators when browsing the course participants
* list.
* @return array
*/
function get_roles_used_in_context($context, $view = false) {
global $CFG;
// filter for roles with all hidden assignments
// no need to return when only pulling roles for reviewing
// e.g. participants page.
$hiddensql = ($view && !has_capability('moodle/role:viewhiddenassigns', $context))? ' AND ra.hidden = 0 ':'';
$contextlist = get_related_contexts_string($context);
$sql = "SELECT DISTINCT r.id,
r.name,
r.shortname,
r.sortorder
FROM {$CFG->prefix}role_assignments ra,
{$CFG->prefix}role r
WHERE r.id = ra.roleid
AND ra.contextid $contextlist
$hiddensql
ORDER BY r.sortorder ASC";
return get_records_sql($sql);
}
/** this function is used to print roles column in user profile page.
* @param int userid
* @param int contextid
* @return string
*/
function get_user_roles_in_context($userid, $contextid){
global $CFG;
$rolestring = '';
$SQL = 'select * from '.$CFG->prefix.'role_assignments ra, '.$CFG->prefix.'role r where ra.userid='.$userid.' and ra.contextid='.$contextid.' and ra.roleid = r.id';
if ($roles = get_records_sql($SQL)) {
foreach ($roles as $userrole) {
$rolestring .= '<a href="'.$CFG->wwwroot.'/user/index.php?contextid='.$userrole->contextid.'&amp;roleid='.$userrole->roleid.'">'.$userrole->name.'</a>, ';
}
}
return rtrim($rolestring, ', ');
}
/**
* Checks if a user can override capabilities of a particular role in this context
* @param object $context
* @param int targetroleid - the id of the role you want to override
* @return boolean
*/
function user_can_override($context, $targetroleid) {
// first check if user has override capability
// if not return false;
if (!has_capability('moodle/role:override', $context)) {
return false;
}
// pull out all active roles of this user from this context(or above)
if ($userroles = get_user_roles($context)) {
foreach ($userroles as $userrole) {
// if any in the role_allow_override table, then it's ok
if (get_record('role_allow_override', 'roleid', $userrole->roleid, 'allowoverride', $targetroleid)) {
return true;
}
}
}
return false;
}
/**
* Checks if a user can assign users to a particular role in this context
* @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) {
// 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 (get_record('role_allow_assign', 'roleid', $userrole->roleid, 'allowassign', $targetroleid)) {
return true;
}
}
}
return false;
}
/** Returns all site roles in correct sort order.
*
*/
function get_all_roles() {
return get_records('role', '', '', 'sortorder ASC');
}
/**
* 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 $userid
* @param view - set to true when roles are pulled for display only
* this is so that we can filter roles with no visible
* assignment, for example, you might want to "hide" all
* course creators when browsing the course participants
* list.
* @return array
*/
function get_user_roles($context, $userid=0, $checkparentcontexts=true, $order='c.contextlevel DESC, r.sortorder ASC', $view=false) {
global $USER, $CFG, $db;
if (empty($userid)) {
if (empty($USER->id)) {
return array();
}
$userid = $USER->id;
}
// set up hidden sql
$hiddensql = ($view && !has_capability('moodle/role:viewhiddenassigns', $context))? ' AND ra.hidden = 0 ':'';
if ($checkparentcontexts && ($parents = get_parent_contexts($context))) {
$contexts = ' ra.contextid IN ('.implode(',' , $parents).','.$context->id.')';
} else {
$contexts = ' ra.contextid = \''.$context->id.'\'';
}
return get_records_sql('SELECT ra.*, r.name, r.shortname
FROM '.$CFG->prefix.'role_assignments ra,
'.$CFG->prefix.'role r,
'.$CFG->prefix.'context c
WHERE ra.userid = '.$userid.
' AND ra.roleid = r.id
AND ra.contextid = c.id
AND '.$contexts . $hiddensql .
' ORDER BY '.$order);
}
/**
* Creates a record in the allow_override table
* @param int sroleid - source roleid
* @param int troleid - target roleid
* @return int - id or false
*/
function allow_override($sroleid, $troleid) {
$record = new object();
$record->roleid = $sroleid;
$record->allowoverride = $troleid;
return insert_record('role_allow_override', $record);
}
/**
* Creates a record in the allow_assign table
* @param int sroleid - source roleid
* @param int troleid - target roleid
* @return int - id or false
*/
function allow_assign($sroleid, $troleid) {
$record = new object;
$record->roleid = $sroleid;
$record->allowassign = $troleid;
return insert_record('role_allow_assign', $record);
}
/**
* Gets a list of roles that this user can assign in this context
* @param object $context
* @return array
*/
function get_assignable_roles ($context, $field="name") {
$options = array();
if ($roles = get_all_roles()) {
foreach ($roles as $role) {
if (user_can_assign($context, $role->id)) {
$options[$role->id] = strip_tags(format_string($role->{$field}, true));
}
}
}
return $options;
}
/**
* Gets a list of roles that this user can override in this context
* @param object $context
* @return array
*/
function get_overridable_roles ($context) {
$options = array();
if ($roles = get_all_roles()) {
foreach ($roles as $role) {
if (user_can_override($context, $role->id)) {
$options[$role->id] = strip_tags(format_string($role->name, true));
}
}
}
return $options;
}
/*
* Returns a role object that is the default role for new enrolments
* in a given course
*
* @param object $course
* @return object $role
*/
function get_default_course_role($course) {
global $CFG;
/// First let's take the default role the course may have
if (!empty($course->defaultrole)) {
if ($role = get_record('role', 'id', $course->defaultrole)) {
return $role;
}
}
/// Otherwise the site setting should tell us
if ($CFG->defaultcourseroleid) {
if ($role = get_record('role', 'id', $CFG->defaultcourseroleid)) {
return $role;
}
}
/// It's unlikely we'll get here, but just in case, try and find a student role
if ($studentroles = get_roles_with_capability('moodle/legacy:student', CAP_ALLOW)) {
return array_shift($studentroles); /// Take the first one
}
return NULL;
}
/**
* who has this capability in this context
* does not handling user level resolving!!!
* (!)pleaes note if $fields is empty this function attempts to get u.*
* which can get rather large.
* i.e 1 person has 2 roles 1 allow, 1 prevent, this will not work properly
* @param $context - object
* @param $capability - string capability
* @param $fields - fields to be pulled
* @param $sort - the sort order
* @param $limitfrom - number of records to skip (offset)
* @param $limitnum - number of records to fetch
* @param $groups - single group or array of groups - group(s) user is in
* @param $exceptions - list of users to exclude
* @param view - set to true when roles are pulled for display only
* this is so that we can filter roles with no visible
* assignment, for example, you might want to "hide" all
* course creators when browsing the course participants
* list.
*/
function get_users_by_capability($context, $capability, $fields='', $sort='',
$limitfrom='', $limitnum='', $groups='', $exceptions='', $doanything=true, $view=false) {
global $CFG;
/// Sorting out groups
if ($groups) {
$groupjoin = 'INNER JOIN '.$CFG->prefix.'groups_members gm ON gm.userid = ra.userid';
if (is_array($groups)) {
$groupsql = 'AND gm.groupid IN ('.implode(',', $groups).')';
} else {
$groupsql = 'AND gm.groupid = '.$groups;
}
} else {
$groupjoin = '';
$groupsql = '';
}
/// Sorting out exceptions
$exceptionsql = $exceptions ? "AND u.id NOT IN ($exceptions)" : '';
/// Set up default fields
if (empty($fields)) {
$fields = 'u.*, ul.timeaccess as lastaccess, ra.hidden';
}
/// Set up default sort
if (empty($sort)) {
$sort = 'ul.timeaccess';
}
$sortby = $sort ? " ORDER BY $sort " : '';
/// Set up hidden sql
$hiddensql = ($view && !has_capability('moodle/role:viewhiddenassigns', $context))? ' AND ra.hidden = 0 ':'';
/// If context is a course, then construct sql for ul
if ($context->contextlevel == CONTEXT_COURSE) {
$courseid = $context->instanceid;
$coursesql1 = "AND ul.courseid = $courseid";
} else {
$coursesql1 = '';
}
/// Sorting out roles with this capability set
if ($possibleroles = get_roles_with_capability($capability, CAP_ALLOW, $context)) {
if (!$doanything) {
if (!$sitecontext = get_context_instance(CONTEXT_SYSTEM)) {
return false; // Something is seriously wrong
}
$doanythingroles = get_roles_with_capability('moodle/site:doanything', CAP_ALLOW, $sitecontext);
}
$validroleids = array();
foreach ($possibleroles as $possiblerole) {
if (!$doanything) {
if (isset($doanythingroles[$possiblerole->id])) { // We don't want these included
continue;
}
}
if ($caps = role_context_capabilities($possiblerole->id, $context, $capability)) { // resolved list
if (isset($caps[$capability]) && $caps[$capability] > 0) { // resolved capability > 0
$validroleids[] = $possiblerole->id;
}
}
}
if (empty($validroleids)) {
return false;
}
$roleids = '('.implode(',', $validroleids).')';
} else {
return false; // No need to continue, since no roles have this capability set
}
/// Construct the main SQL
$select = " SELECT $fields";
$from = " FROM {$CFG->prefix}user u
INNER JOIN {$CFG->prefix}role_assignments ra ON ra.userid = u.id
INNER JOIN {$CFG->prefix}role r ON r.id = ra.roleid
LEFT OUTER JOIN {$CFG->prefix}user_lastaccess ul ON (ul.userid = u.id $coursesql1)
$groupjoin";
$where = " WHERE ra.contextid ".get_related_contexts_string($context)."
AND u.deleted = 0
AND ra.roleid in $roleids
$exceptionsql
$groupsql
$hiddensql";
return get_records_sql($select.$from.$where.$sortby, $limitfrom, $limitnum);
}
/**
* gets all the users assigned this role in this context or higher
* @param int roleid
* @param int contextid
* @param bool parent if true, get list of users assigned in higher context too
* @return array()
*/
function get_role_users($roleid, $context, $parent=false, $fields='', $sort='u.lastname ASC', $view=false) {
global $CFG;
if (empty($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';
}
// whether this assignment is hidden
$hiddensql = ($view && !has_capability('moodle/role:viewhiddenassigns', $context))? ' AND r.hidden = 0 ':'';
if ($parent) {
if ($contexts = get_parent_contexts($context)) {
$parentcontexts = ' OR r.contextid IN ('.implode(',', $contexts).')';
} else {
$parentcontexts = '';
}
} else {
$parentcontexts = '';
}
if ($roleid) {
$roleselect = "AND r.roleid = $roleid";
} else {
$roleselect = '';
}
$SQL = "SELECT $fields
FROM {$CFG->prefix}role_assignments r,
{$CFG->prefix}user u
WHERE (r.contextid = $context->id $parentcontexts)
AND u.id = r.userid $roleselect
$hiddensql
ORDER BY $sort
"; // join now so that we can just use fullname() later
return get_records_sql($SQL);
}
/**
* Counts all the users assigned this role in this context or higher
* @param int roleid
* @param int contextid
* @param bool parent if true, get list of users assigned in higher context too
* @return array()
*/
function count_role_users($roleid, $context, $parent=false) {
global $CFG;
if ($parent) {
if ($contexts = get_parent_contexts($context)) {
$parentcontexts = ' OR r.contextid IN ('.implode(',', $contexts).')';
} else {
$parentcontexts = '';
}
} else {
$parentcontexts = '';
}
$SQL = "SELECT count(*)
FROM {$CFG->prefix}role_assignments r
WHERE (r.contextid = $context->id $parentcontexts)
AND r.roleid = $roleid";
return count_records_sql($SQL);
}
/**
* This function gets the list of courses that this user has a particular capability in
* This is not the most efficient way of doing this
* @param string capability
* @param int $userid
* @return array
*/
function get_user_capability_course($capability, $userid='') {
global $USER;
if (!$userid) {
$userid = $USER->id;
}
$usercourses = array();
$courses = get_records_select('course', '', '', 'id, id');
foreach ($courses as $course) {
if (has_capability($capability, get_context_instance(CONTEXT_COURSE, $course->id))) {
$usercourses[] = $course;
}
}
return $usercourses;
}
/** This function finds the roles assigned directly to this context only
* i.e. no parents role
* @param object $context
* @return array
*/
function get_roles_on_exact_context($context) {
global $CFG;
return get_records_sql("SELECT r.*
FROM {$CFG->prefix}role_assignments ra,
{$CFG->prefix}role r
WHERE ra.roleid = r.id
AND ra.contextid = $context->id");
}
/*
* Switches the current user to another role for the current session and only
* in the given context. If roleid is not valid (eg 0) or the current user
* doesn't have permissions to be switching roles then the user's session
* is compltely reset to have their normal roles.
* @param integer $roleid
* @param object $context
* @return bool
*/
function role_switch($roleid, $context) {
global $USER;
global $db;
/// If we can't use this or are already using it or no role was specified then bail completely and reset
if (empty($roleid) || !has_capability('moodle/role:switchroles', $context)
|| !empty($USER->switchrole[$context->id]) || !confirm_sesskey()) {
load_user_capability('', $context); // Reset all permissions for this context to normal
unset($USER->switchrole[$context->id]); // Delete old capabilities
return true;
}
/// We're allowed to switch but can we switch to the specified role? Use assignable roles to check.
if (!$roles = get_assignable_roles($context)) {
return false;
}
if (empty($roles[$roleid])) { /// We can't switch to this particular role
return false;
}
if (!$sitecontext = get_context_instance(CONTEXT_SYSTEM)) {
return false;
}
/// We have a valid roleid that this user can switch to, so let's set up the session
$USER->switchrole[$context->id] = $roleid; // So we know later what state we are in
unset($USER->capabilities[$context->id]); // Delete old capabilities
if ($capabilities = get_records_select('role_capabilities', "roleid = $roleid AND contextid = $sitecontext->id")) {
foreach ($capabilities as $capability) {
$USER->capabilities[$context->id][$capability->capability] = $capability->permission;
}
}
/// Add some permissions we are really going to always need, even if the role doesn't have them!
$USER->capabilities[$context->id]['moodle/course:view'] = CAP_ALLOW;
return true;
}
// get any role that has an override on exact context
function get_roles_with_override_on_context($context) {
global $CFG;
return get_records_sql("SELECT r.*
FROM {$CFG->prefix}role_capabilities rc,
{$CFG->prefix}role r
WHERE rc.roleid = r.id
AND rc.contextid = $context->id");
}
// get all capabilities for this role on this context (overrids)
function get_capabilities_from_role_on_context($role, $context) {
global $CFG;
return get_records_sql("SELECT *
FROM {$CFG->prefix}role_capabilities
WHERE contextid = $context->id
AND roleid = $role->id");
}
// find out which roles has assignment on this context
function get_roles_with_assignment_on_context($context) {
global $CFG;
return get_records_sql("SELECT r.*
FROM {$CFG->prefix}role_assignments ra,
{$CFG->prefix}role r
WHERE ra.roleid = r.id
AND ra.contextid = $context->id");
}
/* find all user assignemnt of users for this role, on this context
*/
function get_users_from_role_on_context($role, $context) {
global $CFG;
return get_records_sql("SELECT *
FROM {$CFG->prefix}role_assignments
WHERE contextid = $context->id
AND roleid = $role->id");
}
/*
* Simple function returning a boolean true if roles exist, otherwise false
*/
function user_has_role_assignment($userid, $roleid, $contextid=0) {
if ($contextid) {
return record_exists('role_assignments', 'userid', $userid, 'roleid', $roleid, 'contextid', $contextid);
} else {
return record_exists('role_assignments', 'userid', $userid, 'roleid', $roleid);
}
}
?>
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