moodle/lib/accesslib.php
2006-08-09 13:14:15 +00:00

1491 lines
50 KiB
PHP
Executable File

<?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_ALLOW', 1);
define('CAP_PREVENT', -1);
define('CAP_PROHIBIT', -1000);
// context definitions
define('CONTEXT_SYSTEM', 10);
define('CONTEXT_PERSONAL', 20);
define('CONTEXT_USERID', 30);
define('CONTEXT_COURSECAT', 40);
define('CONTEXT_COURSE', 50);
define('CONTEXT_GROUP', 60);
define('CONTEXT_MODULE', 70);
define('CONTEXT_BLOCK', 80);
/**
* This functions get all the course categories in proper order
* @param int $contextid
* @param int $type
* @return array of contextids
*/
function get_parent_cats($contextid, $type) {
$parents = array();
$context = get_record('context', 'id', $contextid);
switch($type) {
case CONTEXT_COURSECAT:
$cat = get_record('course_categories','id',$context->instanceid);
while ($cat->parent) {
$context = get_context_instance(CONTEXT_COURSECAT, $cat->parent);
$parents[] = $context->id;
$cat = get_record('course_categories','id',$cat->parent);
}
break;
case CONTEXT_COURSE:
$course = get_record('course', 'id', $context->instanceid);
$cat = get_record('course_categories','id',$course->category);
$catinstance = get_context_instance(CONTEXT_COURSECAT, $course->category);
$parents[] = $catinstance->id;
// what to do with cat 0?
while ($cat->parent) {
$context = get_context_instance(CONTEXT_COURSECAT, $cat->parent);
$parents[] = $context->id;
$cat = get_record('course_categories','id',$cat->parent);
}
break;
default:
break;
}
return array_reverse($parents);
}
/* Functions for Roles & Capabilites */
/**
* This function returns whether the current user has the capability of performing a function
* For example, we can do has_capability('mod/forum:replypost',$cm) in forum
* only one of the 4 (moduleinstance, courseid, site, userid) would be set at 1 time
* This is a recursive funciton.
* Might change to require_capability, and throw an error if not authorized.
* @uses $USER
* @param string $capability - name of the capability
* @param int $contextid
* @param kill bool - if set, kill when the user has no capability
* @return bool
*/
function has_capability($capability, $contextid, $kill=false, $userid=NULL) {
global $USER;
if ($userid && $userid != $USER->id) { // loading other user's capability
$capabilities = load_user_capability($capability, $contextid, $userid);
} else {
$capabilities = $USER->capabilities;
}
//echo ("capablity is ".$capability);
//print_object($contextid);
$context = get_record('context','id',$contextid);
// Check site
$sitecontext = get_context_instance(CONTEXT_SYSTEM, SITEID);
if (isset($capabilities[$sitecontext->id]['moodle/site:doanything'])) {
return ($capabilities[$sitecontext->id]['moodle/site:doanything']);
}
switch (context_level($contextid)) {
case CONTEXT_COURSECAT:
// Check parent cats.
$parentcats = get_parent_cats($contextid, CONTEXT_COURSECAT);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['moodle/site:doanything'])) {
return ($capabilities[$parentcat]['moodle/site:doanything']);
}
}
break;
case CONTEXT_COURSE:
// Check parent cat.
$parentcats = get_parent_cats($contextid, CONTEXT_COURSE);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
return ($capabilities[$parentcat]['do_anything']);
}
}
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->id, CONTEXT_COURSE);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat->id]['do_anything'])) {
return ($capabilities[$parentcat->id]['do_anything']);
}
}
$coursecontext = '';
if (isset($capabilities[$courseinstance->id]['do_anything'])) {
return ($capabilities[$courseinstance->id]['do_anything']);
}
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($courseinstance->id, CONTEXT_COURSE)) {
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
return ($capabilities[$parentcat]['do_anything']);
}
}
}
if (isset($capabilities[$courseinstance->id]['do_anything'])) {
return ($capabilities[$courseinstance->id]['do_anything']);
}
break;
case CONTEXT_BLOCK:
// 1 to 1 to course.
// Find course.
$block = get_record('block_instance','id',$context->instanceid);
$courseinstance = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
$parentcats = get_parent_cats($courseinstance->id, CONTEXT_COURSE);
foreach ($parentcats as $parentcat) {
if (isset($capabilities[$parentcat]['do_anything'])) {
return ($capabilities[$parentcat]['do_anything']);
}
}
if (isset($capabilities[$courseinstance->id]['do_anything'])) {
return ($capabilities[$courseinstance->id]['do_anything']);
}
break;
default:
// CONTEXT_SYSTEM: CONTEXT_PERSONAL: CONTEXT_USERID:
// Do nothing.
break;
}
// Last: check self.
if (isset($capabilities[$contextid]['do_anything'])) {
return ($capabilities[$contextid]['do_anything']);
}
// do_anything has not been set, we now look for it the normal way.
return capability_search($capability, $contextid, $kill, $capabilities);
}
/**
* 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 $contextid - the context id
* @param $kill - boolean. Error out and exit if the user doesn't have the
* capability?
* @param $capabilities - either $USER->capability or loaded array
* @return permission (int)
*/
function capability_search($capability, $contextid, $kill=false, $capabilities) {
global $USER, $CFG;
if ($CFG->debug) {
notify("We are looking for $capability in context $contextid", 'notifytiny');
}
if (isset($capabilities[$contextid][$capability])) {
return ($capabilities[$contextid][$capability]);
}
/* Then, we check the cache recursively */
$context = get_record('context','id',$contextid); // shared
$permission = 0;
switch (context_level($contextid)) {
case CONTEXT_SYSTEM: // by now it's a definite an inherit
$permission = 0;
break;
case CONTEXT_PERSONAL:
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
$permission = (capability_search($capability, $parent->id, false, $capabilities));
break;
case CONTEXT_USERID:
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
$permission = (capability_search($capability, $parent->id, false, $capabilities));
break;
case CONTEXT_COURSECAT: // Coursecat -> coursecat or site
$coursecat = get_record('course_categories','id',$context->instanceid);
if ($coursecat->parent) { // return parent value if exist
$parent = get_context_instance(CONTEXT_COURSECAT, $coursecat->parent);
} else { // else return site value
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
}
$permission = (capability_search($capability, $parent->id, false, $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);
$parent = get_context_instance(CONTEXT_COURSECAT, $course->category);
$permission = (capability_search($capability, $parent->id, false, $capabilities));
break;
case CONTEXT_GROUP: // 1 to 1 to course
$group = get_record('groups','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $group->courseid);
$permission = (capability_search($capability, $parent->id, false, $capabilities));
break;
case CONTEXT_MODULE: // 1 to 1 to course
$cm = get_record('course_modules','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $cm->course);
$permission = (capability_search($capability, $parent->id, false, $capabilities));
break;
case CONTEXT_BLOCK: // 1 to 1 to course
$block = get_record('block_instance','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
$permission = (capability_search($capability, $parent->id, false, $capabilities));
break;
default:
error ('This is an unknown context!');
return false;
}
if ($kill && ($permission <= 0)) {
error ('You do not have the required capability '.$capability);
}
return $permission;
}
/**
* 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!
* @param $userid - the id of the user whose capabilities we want to load
* @return array
* possible just s simple 2D array with [contextid][capabilityname]
* [Capabilities] => [26][forum_post] = 1
* [26][forum_start] = -8990
* [26][forum_edit] = -1
* [273][blah blah] = 1
* [273][blah blah blah] = 2
*/
function load_user_capability($capability='', $contextid ='', $userid='') {
global $USER, $CFG;
if (empty($userid)) {
$userid = $USER->id;
} else {
$otheruserid = $userid;
}
if ($capability) {
$capsearch = ' AND rc.capability = '.$capability.' ';
} else {
$capsearch ='';
}
// First we generate a list of all relevant contexts of the user
if ($contextid) { // if context is specified
$context = get_record('context', 'id', $contextid);
$usercontexts = get_parent_contexts($context->id);
$listofcontexts = '('.implode(',', $usercontexts).')';
} else { // else, we load everything
$usercontexts = get_records('role_assignments','userid',$userid);
$listofcontexts = '(';
foreach ($usercontexts as $usercontext) {
$listofcontexts .= $usercontext->contextid;
$listofcontexts .= ',';
}
$listofcontexts = rtrim ($listofcontexts, ",");
$listofcontexts .= ')';
}
// 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, SITEID);
$SQL = " SELECT rc.capability, c1.id, (c1.level * 100) AS level,
SUM(rc.permission) AS sum
FROM
{$CFG->prefix}role_assignments AS ra
INNER JOIN {$CFG->prefix}role_capabilities AS rc ON ra.roleid=rc.roleid
INNER JOIN {$CFG->prefix}context AS c1 ON ra.contextid=c1.id
WHERE
ra.userid=$userid AND
c1.id IN $listofcontexts AND
rc.contextid=$siteinstance->id
$capsearch
GROUP BY
rc.capability,level,c1.id
HAVING
sum != 0
UNION
SELECT rc.capability, c1.id, (c1.level * 100 + c2.level) AS level,
SUM(rc.permission) AS sum
FROM
{$CFG->prefix}role_assignments AS ra
INNER JOIN {$CFG->prefix}role_capabilities AS rc ON ra.roleid=rc.roleid
INNER JOIN {$CFG->prefix}context AS c1 ON ra.contextid=c1.id
LEFT OUTER JOIN {$CFG->prefix}context AS c2 ON rc.contextid=c2.id
WHERE
ra.userid=$userid AND
c1.id IN $listofcontexts AND
c2.id IN $listofcontexts AND rc.contextid != $siteinstance->id
$capsearch
GROUP BY
rc.capability, level, c1.id
HAVING
sum != 0
ORDER BY
level ASC
";
// echo "$SQL"; // debug
$capabilities = array(); // Reinitialize.
$rs = get_recordset_sql($SQL);
if ($rs && $rs->RecordCount() > 0) {
while (!$rs->EOF) {
$array = $rs->fields;
$temprecord = new object;
foreach ($array as $key=>$val) {
$temprecord->{$key} = $val;
}
$capabilities[] = $temprecord;
$rs->MoveNext();
}
}
/* so up to this point we should have somethign like this
* $capabilities[1] ->level = 1000
->module = SITEID
->capability = do_anything
->id = 1 (id is the context id)
->sum = 0
* $capabilities[2] ->level = 1000
->module = SITEID
->capability = post_messages
->id = 1
->sum = -9000
* $capabilittes[3] ->level = 3000
->module = course
->capability = view_course_activities
->id = 25
->sum = 1
* $capabilittes[4] ->level = 3000
->module = course
->capability = view_course_activities
->id = 26
->sum = 0 (this is another course)
* $capabilities[5] ->level = 3050
->module = course
->capability = view_course_activities
->id = 25 (override in course 25)
->sum = -1
* ....
* now we proceed to write the session array, going from top to bottom
* at anypoint, we need to go up and check parent to look for prohibit
*/
// print_object($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 ........
*/
$usercap = array(); // for other user's capabilities
foreach ($capabilities as $capability) {
if ($otheruserid) { // we are pulling out other user's capabilities, do not write to session
if (capability_prohibits($capability->capability, $capability->id, $capability->sum, $usercap)) {
$usercap[$capability->id][$capability->capability] = -9000;
continue;
}
$usercap[$capability->id][$capability->capability] = $capability->sum;
} else {
if (capability_prohibits($capability->capability, $capability->id, $capability->sum)) { // if any parent or parent's parent is set to prohibit
$USER->capabilities[$capability->id][$capability->capability] = -9000;
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
// no point writing 0, since 0 = inherit
// we need to write even if it's 0, because it could be an inherit override
$USER->capabilities[$capability->id][$capability->capability] = $capability->sum;
}
}
// now we don't care about the huge array anymore, we can dispose it.
unset($capabilities);
if ($otheruseid) {
return $usercap; // return the array
}
// see array in session to see what it looks like
}
/**
* 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 $contextid - the context id
* @param $array - when loading another user caps, their caps are not stored in session but an array
*/
function capability_prohibits($capability, $contextid, $sum='', $array='') {
global $USER;
if ($sum < -8000) {
// If this capability is set to prohibit.
return true;
}
if (isset($array)) {
if (isset($array[$contextid][$capability])
&& $array[$contextid][$capability] < -8000) {
return true;
}
} else {
// Else if set in session.
if (isset($USER->capabilities[$contextid][$capability])
&& $USER->capabilities[$contextid][$capability] < -8000) {
return true;
}
}
$context = get_record('context', 'id', $contextid);
switch (context_level($contextid)) {
case CONTEXT_SYSTEM:
// By now it's a definite an inherit.
return 0;
break;
case CONTEXT_PERSONAL:
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
return (capability_prohibits($capability, $parent->id));
break;
case CONTEXT_USERID:
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
return (capability_prohibits($capability, $parent->id));
break;
case CONTEXT_COURSECAT:
// Coursecat -> coursecat or site.
$coursecat = get_record('course_categories','id',$context->instanceid);
if ($coursecat->parent) {
// return parent value if exist.
$parent = get_context_instance(CONTEXT_COURSECAT, $coursecat->parent);
} else {
// Return site value.
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
}
return (capability_prohibits($capability, $parent->id));
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);
$parent = get_context_instance(CONTEXT_COURSECAT, $course->category);
return (capability_prohibits($capability, $parent->id));
break;
case CONTEXT_GROUP:
// 1 to 1 to course.
$group = get_record('groups','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $group->courseid);
return (capability_prohibits($capability, $parent->id));
break;
case CONTEXT_MODULE:
// 1 to 1 to course.
$cm = get_record('course_modules','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $cm->course);
return (capability_prohibits($capability, $parent->id));
break;
case CONTEXT_BLOCK:
// 1 to 1 to course.
$block = get_record('block_instance','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
return (capability_prohibits($capability, $parent->id));
break;
default:
error ('This is an unknown context!');
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.
}
}
}
/**
* This function handles the upgrade process of assigning default roles
* to the existing users
*/
function moodle_upgrade_roles_system_17() {
global $CFG;
// Create a system wide context for assignemnt.
$systemcontext = $context = get_context_instance(CONTEXT_SYSTEM, SITEID);
// loading legacy roles and capabilities (1 legacy capability per legacy role at system levle)
$adminrole = create_role(get_string('administrator'), get_string('administratordescription'), 'moodle/legacy:admin');
if (!assign_capability('moodle/site:doanything', CAP_ALLOW, $adminrole, $systemcontext->id)) {
error('Could not assign moodle/site:doanything to the admin role');
}
$coursecreatorrole = create_role(get_string('coursecreators'), get_string('coursecreatorsdescription'), 'moodle/legacy:coursecreator');
$noneditteacherrole = create_role(get_string('noneditingteacher'), get_string('noneditingteacherdescription'), 'moodle/legacy:teacher');
$editteacherrole = create_role(get_string('defaultcourseteacher'), get_string('defaultcourseteacherdescription'), 'moodle/legacy:editingteacher');
$studentrole = create_role(get_string('defaultcoursestudent'), get_string('defaultcoursestudentdescription'), 'moodle/legacy:student');
$guestrole = create_role(get_string('guest'), get_string('guestdescription'), 'moodle/legacy:guest');
// Look inside user_admin, user_creator, $user_teachers, $user_students
// and assign roles. If a user has both teacher and student role, only
// teacher role is assigned. The assignment should be system level.
/**
* Upgrade the admins.
*/
// sort using id asc, first one is primary admin
$useradmins = get_records_sql('SELECT * from '.$CFG->prefix.'user_admins ORDER BY ID ASC');
foreach ($useradmins as $admin) {
role_assign($adminrole, $admin->userid, 0, $systemcontext->id);
}
// Do we assign the capability moodle/doanything to the admin roles here?
/**
* Upgrade course creators.
*/
$usercoursecreators = get_records('user_coursecreators');
foreach ($usercoursecreators as $coursecreator) {
role_assign($$coursecreatorrole, $coursecreator->userid, 0, $systemcontext->id);
}
/**
* Upgrade editting teachers and non-editting teachers.
*/
$userteachers = get_records('user_teachers');
foreach ($userteachers as $teacher) {
$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);
}
}
/**
* Upgrade students.
*/
$userstudents = get_records('user_students');
foreach ($userstudents as $student) {
$coursecontext = get_context_instance(CONTEXT_COURSE, $student->course);
role_assign($studentrole, $student->userid, 0, $coursecontext->id);
}
/**
* Upgrade guest (only 1 entry).
*/
$guestuser = get_record('user', 'username', 'guest');
role_assign($guestrole, $guestuser->id, 0, $systemcontext->id);
//
// Should we delete the tables after we are done?
//
set_config('rolesactive', 1);
}
/**
* 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) {
$systemcontext = get_context_instance(CONTEXT_SYSTEM, SITEID);
// The legacy capabilities are:
// 'moodle/legacy:guest'
// 'moodle/legacy:student'
// 'moodle/legacy:teacher'
// 'moodle/legacy:editingteacher'
// 'moodle/legacy:coursecreator'
// 'moodle/legacy:admin'
if (!$roles = get_roles_with_capability('moodle/legacy:'.$type, CAP_ALLOW)) {
return false;
}
foreach ($roles as $role) {
// Assign a site level capability.
if(!assign_capability($capability, $perm, $role->id, $systemcontext->id)) {
return false;
}
}
}
return true;
}
// checks to see if a capability is a legacy capability, returns bool
function islegacy($capabilityname) {
if (strstr($capabilityname, 'legacy') === false) {
return false;
} else {
return true;
}
}
/************************************
* Context Manipulation functions *
**********************************/
/**
* This should be called prolly everytime a user, group, module, course,
* coursecat or site is set up maybe?
* @param $level
* @param $instanceid
*/
function create_context($level, $instanceid) {
if (!get_record('context','level',$level,'instanceid',$instanceid)) {
$context = new object;
$context->level = $level;
$context->instanceid = $instanceid;
return insert_record('context',$context);
}
}
/**
* Get the context instance as an object. This function will create the
* context instance if it does not exist yet.
* @param $level
* @param $instance
*/
function get_context_instance($level, $instance=SITEID) {
// echo "getting level $level instance $instance";
// XXX TODO Add caching here
if (!$context = get_record('context', 'level', $level, 'instanceid', $instance)) {
//echo "creating ...";
create_context($level, $instance);
$context = get_record('context', 'level', $level, 'instanceid', $instance);
}
return $context;
}
/**
* Looks up the context level.
* @param int $contextid
* @return int
*/
function context_level($contextid) {
$context = get_record('context','id',$contextid);
return ($context->level);
}
/************************************
* DB TABLE RELATED FUNCTIONS *
************************************/
/**********************************************
* function that creates a role
* @param name - role name
* @param description - role description
* @param legacy - optional legacy capability
* @return id or false
*/
function create_role($name, $description, $legacy='') {
// check for duplicate role name
if ($role = get_record('role','name', $name)) {
print_object($role);
error('there is already a role with this name!');
}
$role->name = $name;
$role->description = $description;
if ($id = insert_record('role', $role)) {
if ($legacy) {
$context = get_context_instance(CONTEXT_SYSTEM, SITEID);
assign_capability($legacy, CAP_ALLOW, $id, $context->id);
}
return $id;
} else {
return false;
}
}
/**
* Function to write context specific overrides, or default capabilities.
* @param module - string name
* @param capability - string name
* @param contextid - context id
* @param roleid - role id
* @param permission - int 1,-1 or -1000
*/
function assign_capability($capability, $permission, $roleid, $contextid) {
global $USER;
if (empty($permission) || $permission == 0) { // if permission is not set
unassign_capability($capability, $roleid, $contextid);
}
$cap = new object;
$cap->contextid = $contextid;
$cap->roleid = $roleid;
$cap->capability = $capability;
$cap->permission = $permission;
$cap->timemodified = time();
$cap->modifierid = $USER->id;
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.
* @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) {
global $CFG;
$selectroles = "SELECT r.*
FROM {$CFG->prefix}role AS r,
{$CFG->prefix}role_capabilities AS rc
WHERE rc.capability = '$capability'
AND rc.roleid = r.id";
if (isset($permission)) {
$selectroles .= " AND rc.permission = '$permission'";
}
return get_records_sql($selectroles);
}
/**
* This function makes a role-assignment (user to a role)
* @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) {
global $USER, $CFG;
if ($CFG->debug) {
notify("Assign roleid $roleid userid $userid contextid $contextid", 'notifytiny');
}
if (empty($roleid)) {
error ('you need to select a role');
}
if (empty($userid) && empty($groupid)) {
error ('you need to assign this role to a user or a group');
}
if (empty($contextid)) {
error ('you need to assign this role to a context, e.g. a course, or an activity');
}
$ra = new object;
$ra->roleid = $roleid;
$ra->contextid = $contextid;
$ra->userid = $userid;
$ra->hidden = $hidden;
$ra->groupid = $groupid;
$ra->timestart = $timestart;
$ra->timeend = $timeend;
$ra->timemodified = time();
$ra->modifier = $USER->id;
return insert_record('role_assignments', $ra);
}
/**
* Deletes a role assignment.
* @param $roleid
* @param $userid
* @param $groupid
* @param $contextid
* @return boolean - success or failure
*/
function role_unassign($roleid, $userid, $groupid, $contextid) {
if ($groupid) {
// do nothing yet as this is not implemented
}
else {
return delete_records('role_assignments', 'userid', $userid,
'roleid', $roleid, 'contextid', $contextid);
}
}
/**
* 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 {
$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 = array();
$cachedcaps = get_cached_capabilities($component);
if ($cachedcaps) {
foreach ($cachedcaps as $cachedcap) {
array_push($storedcaps, $cachedcap->name);
}
}
$filecaps = load_capability_def($component);
// Are there new capabilities in the file definition?
$newcaps = array();
foreach ($filecaps as $filecap => $def) {
if (!$storedcaps ||
($storedcaps && in_array($filecap, $storedcaps) === false)) {
$newcaps[$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;
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, $capdef['legacy'])) {
error('Could not assign legacy capabilities');
return false;
}
}
// Are there any capabilities that have been removed from the file
// definition that we need to delete from the stored capabilities and
// role assignments?
capabilities_cleanup($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 $role) {
if (!unassign_capability($role->id, $cachedcap->name)) {
error('Could not unassign deprecated capability '.
$cachedcap->name.' from role '.$role->name);
}
}
}
} // End if.
}
}
return $removedcount;
}
/************************************************************
* * UI FUNCTIONS * *
************************************************************/
/**
* prints human readable context identifier.
*/
function print_context_name($contextid) {
$name = '';
$context = get_record('context', 'id', $contextid);
switch ($context->level) {
case CONTEXT_SYSTEM: // by now it's a definite an inherit
$name = get_string('site');
break;
case CONTEXT_PERSONAL:
$name = get_string('personal');
break;
case CONTEXT_USERID:
if ($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)) {
$name = get_string('blocks').': '.get_string($block->name, 'block_'.$block->name);
}
}
break;
default:
error ('This is an unknown context!');
return false;
}
return $name;
}
/**
* Extracts the relevant capabilities given a contextid.
* All case based, example an instance of forum context.
* Will fetch all forum related capabilities, while course contexts
* Will fetch all capabilities
* @param int contextid
* @return array();
*
* capabilities
* `name` varchar(150) NOT NULL,
* `captype` varchar(50) NOT NULL,
* `contextlevel` int(10) NOT NULL,
* `component` varchar(100) NOT NULL,
*/
function fetch_context_capabilities($contextid) {
global $CFG;
$sort = 'ORDER BY contextlevel,component,id'; // To group them sensibly for display
switch (context_level($contextid)) {
case CONTEXT_SYSTEM: // all
$SQL = "select * from {$CFG->prefix}capabilities";
break;
case CONTEXT_PERSONAL:
break;
case CONTEXT_USERID:
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
$context = get_record('context','id',$contextid);
$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
$context = get_record('context','id',$contextid);
$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;
}
$records = get_records_sql($SQL.' '.$sort);
return $records;
}
/**
* This function pulls out all the resolved capabilities (overrides and
* defaults) of a role used in capability overrieds in contexts at a given
* context.
* @param int $contextid
* @param int $roleid
* @return array
*/
function role_context_capabilities($roleid, $contextid) {
global $CFG;
$sitecontext = get_context_instance(CONTEXT_SYSTEM, SITEID);
if ($sitecontext->id == $contextid) {
return array();
}
// first of all, figure out all parental contexts
$context = get_record('context', 'id', $contextid);
$contexts = array_reverse(get_parent_contexts($context));
$contexts = '('.implode(',', $contexts).')';
$SQL = "SELECT rc.* FROM {$CFG->prefix}role_capabilities rc, {$CFG->prefix}context c
where rc.contextid in $contexts
and rc.roleid = $roleid
and rc.contextid = c.id
ORDER BY c.level DESC, rc.capability DESC";
$records = get_records_sql($SQL);
$capabilities = array();
// We are traversing via reverse order.
foreach ($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 contextid, 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_level($context->id)) {
case CONTEXT_SYSTEM: // no parent
return null;
break;
case CONTEXT_PERSONAL:
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
return array($parent->id);
break;
case CONTEXT_USERID:
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
return array($parent->id);
break;
case CONTEXT_COURSECAT: // Coursecat -> coursecat or site
$coursecat = get_record('course_categories','id',$context->instanceid);
if ($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
$parent = get_context_instance(CONTEXT_SYSTEM, SITEID);
return array($parent->id);
}
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);
$parent = get_context_instance(CONTEXT_COURSECAT, $course->category);
return array_merge(array($parent->id), get_parent_contexts($parent));
break;
case CONTEXT_GROUP: // 1 to 1 to course
$group = get_record('groups','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $group->courseid);
return array_merge(array($parent->id), get_parent_contexts($parent));
break;
case CONTEXT_MODULE: // 1 to 1 to course
$cm = get_record('course_modules','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $cm->course);
return array_merge(array($parent->id), get_parent_contexts($parent));
break;
case CONTEXT_BLOCK: // 1 to 1 to course
$block = get_record('block_instance','id',$context->instanceid);
$parent = get_context_instance(CONTEXT_COURSE, $block->pageid); // needs check
return array_merge(array($parent->id), get_parent_contexts($parent));
break;
default:
error ('This is an unknown context!');
return false;
}
}
/**
* This function gets the capability of a role in a given context.
* It is needed when printing override forms.
* @param int $contextid
* @param int $roleid // no need? since role is used in extraction in $capability
* @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) {
return $capabilities[$contextid][$capability];
}
// a big switch statement
function get_capability_string($capname) {
$names = split('/', $capname);
$componentname = split(':', $names[1]);
$componentname = $componentname[0];
$capability = split(':', $capname);
$capability = 'capability_'.$capability[1];
switch ($names[0]) {
case 'mod':
$string = get_string($capability, $componentname);
break;
case 'block':
$string = get_string($capability, 'block_'.$componentname);
break;
case 'moodle':
$string = get_string($capability);
break;
case 'enrol':
$string = get_string($capability, 'enrol_'.$componentname);
default:
$string = get_string($capability);
break;
}
return $string;
}
// this gets the mod/block/course/core etc strings
function get_component_string($component, $contextlevel) {
switch ($contextlevel) {
case CONTEXT_SYSTEM:
$string = get_string('system');
break;
case CONTEXT_PERSONAL:
$string = get_string('personal');
break;
case CONTEXT_USERID:
$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;
}
?>