mirrored from git://git.moodle.org/moodle.git
/
accesslib.php
executable file
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/
accesslib.php
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<?php // $Id$
///////////////////////////////////////////////////////////////////////////
// //
// NOTICE OF COPYRIGHT //
// //
// Moodle - Modular Object-Oriented Dynamic Learning Environment //
// http://moodle.org //
// //
// Copyright (C) 1999-2004 Martin Dougiamas http://dougiamas.com //
// //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation; either version 2 of the License, or //
// (at your option) any later version. //
// //
// This program is distributed in the hope that it will be useful, //
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
// GNU General Public License for more details: //
// //
// http://www.gnu.org/copyleft/gpl.html //
// //
///////////////////////////////////////////////////////////////////////////
/**
* Public API vs internals
* -----------------------
*
* General users probably only care about
*
* - get_context_instance()
* - has_capability()
* - get_user_courses_bycap()
* - get_context_users_bycap()
* - more?
*
* Advanced use
* - $ACCESS global
* - has_cap_fad()
* - more?
*
* accessdata
* ----------
*
* Access control data is held in the "accessdata" array
* which - for the logged-in user, will be in $USER->access
*
* For other users can be generated and passed around (but see
* the $ACCESS global).
*
* accessdata ($ad) is a multidimensional array, holding
* role assignments (RAs), role-capabilities-perm sets
* (role defs) and a list of courses we have loaded
* data for.
*
* Things are keyed on "contextpaths" (the path field of
* the context table) for fast walking up/down the tree.
*
* $ad[ra][$contextpath]= array($roleid)
* [$contextpath]= array($roleid)
* [$contextpath]= array($roleid)
*
* Role definitions are stored like this
* (no cap merge is done - so it's compact)
*
* $ad[rdef][$contextpath:$roleid][mod/forum:viewpost] = 1
* [mod/forum:editallpost] = -1
* [mod/forum:startdiscussion] = -1000
*
* See how has_cap_fad() walks up/down the tree.
*
* Normally - specially for the logged-in user, we only load
* rdef and ra down to the course level, but not below. This
* keeps accessdata small and compact. Below-the-course ra/rdef
* are loaded as needed. We keep track of which courses we
* have loaded ra/rdef in
*
* $ad[loaded] = array($contextpath, $contextpath)
*
* Stale accessdata
* ----------------
*
* For the logged-in user, accessdata is long-lived.
*
* On each pageload we load $DIRTYPATHS which lists
* context paths affected by changes. Any check at-or-below
* a dirty context will trigger a transparent reload of accessdata.
*
* Changes at the sytem level will force the reload for everyone.
*
* Default role caps
* -----------------
* The default role assignment is not in the DB, so we
* add it manually to accessdata.
*
* This means that functions that work directly off the
* DB need to ensure that the default role caps
* are dealt with appropriately.
*
*/
require_once $CFG->dirroot.'/lib/blocklib.php';
// permission definitions
define('CAP_INHERIT', 0);
define('CAP_ALLOW', 1);
define('CAP_PREVENT', -1);
define('CAP_PROHIBIT', -1000);
// context definitions
define('CONTEXT_SYSTEM', 10);
define('CONTEXT_PERSONAL', 20);
define('CONTEXT_USER', 30);
define('CONTEXT_COURSECAT', 40);
define('CONTEXT_COURSE', 50);
define('CONTEXT_GROUP', 60);
define('CONTEXT_MODULE', 70);
define('CONTEXT_BLOCK', 80);
// capability risks - see http://docs.moodle.org/en/Hardening_new_Roles_system
define('RISK_MANAGETRUST', 0x0001);
define('RISK_CONFIG', 0x0002);
define('RISK_XSS', 0x0004);
define('RISK_PERSONAL', 0x0008);
define('RISK_SPAM', 0x0010);
require_once($CFG->dirroot.'/group/lib.php');
$context_cache = array(); // Cache of all used context objects for performance (by level and instance)
$context_cache_id = array(); // Index to above cache by id
function get_role_context_caps($roleid, $context) {
//this is really slow!!!! - do not use above course context level!
$result = array();
$result[$context->id] = array();
// first emulate the parent context capabilities merging into context
$searchcontexts = array_reverse(get_parent_contexts($context));
array_push($searchcontexts, $context->id);
foreach ($searchcontexts as $cid) {
if ($capabilities = get_records_select('role_capabilities', "roleid = $roleid AND contextid = $cid")) {
foreach ($capabilities as $cap) {
if (!array_key_exists($cap->capability, $result[$context->id])) {
$result[$context->id][$cap->capability] = 0;
}
$result[$context->id][$cap->capability] += $cap->permission;
}
}
}
// now go through the contexts bellow given context
$searchcontexts = array_keys(get_child_contexts($context));
foreach ($searchcontexts as $cid) {
if ($capabilities = get_records_select('role_capabilities', "roleid = $roleid AND contextid = $cid")) {
foreach ($capabilities as $cap) {
if (!array_key_exists($cap->contextid, $result)) {
$result[$cap->contextid] = array();
}
$result[$cap->contextid][$cap->capability] = $cap->permission;
}
}
}
return $result;
}
function get_role_caps($roleid) {
$result = array();
if ($capabilities = get_records_select('role_capabilities',"roleid = $roleid")) {
foreach ($capabilities as $cap) {
if (!array_key_exists($cap->contextid, $result)) {
$result[$cap->contextid] = array();
}
$result[$cap->contextid][$cap->capability] = $cap->permission;
}
}
return $result;
}
function merge_role_caps($caps, $mergecaps) {
if (empty($mergecaps)) {
return $caps;
}
if (empty($caps)) {
return $mergecaps;
}
foreach ($mergecaps as $contextid=>$capabilities) {
if (!array_key_exists($contextid, $caps)) {
$caps[$contextid] = array();
}
foreach ($capabilities as $capability=>$permission) {
if (!array_key_exists($capability, $caps[$contextid])) {
$caps[$contextid][$capability] = 0;
}
$caps[$contextid][$capability] += $permission;
}
}
return $caps;
}
/**
* Gets the accessdata for role "sitewide"
* (system down to course)
*
* @return array
*/
function get_role_access($roleid, $acc=NULL) {
global $CFG;
/* Get it in 1 cheap DB query...
* - relevant role caps at the root and down
* to the course level - but not below
*/
if (is_null($acc)) {
$acc = array(); // named list
$acc['ra'] = array();
$acc['rdef'] = array();
$acc['loaded'] = array();
}
$base = '/' . SYSCONTEXTID;
//
// Overrides for the role IN ANY CONTEXTS
// down to COURSE - not below -
//
$sql = "SELECT ctx.path,
rc.capability, rc.permission
FROM {$CFG->prefix}context ctx
JOIN {$CFG->prefix}role_capabilities rc
ON rc.contextid=ctx.id
WHERE rc.roleid = {$roleid}
AND ctx.contextlevel <= ".CONTEXT_COURSE."
ORDER BY ctx.depth, ctx.path";
$rs = get_recordset_sql($sql);
if ($rs->RecordCount()) {
while ($rd = rs_fetch_next_record($rs)) {
$k = "{$rd->path}:{$roleid}";
$acc['rdef'][$k][$rd->capability] = $rd->permission;
}
unset($rd);
}
rs_close($rs);
return $acc;
}
/**
* Get the id for the not-logged-in role - or set it up if needed
* @return bool
*/
function get_notloggedin_roleid($return=false) {
global $CFG, $USER;
if (empty($CFG->notloggedinroleid)) { // Let's set the default to the guest role
if ($role = get_guest_role()) {
set_config('notloggedinroleid', $role->id);
return $role->id;
} else {
return false;
}
} else {
return $CFG->notloggedinroleid;
}
return (get_record('role','id', $CFG->notloggedinas));
}
/**
* Get the default guest role
* @return object role
*/
function get_guest_role() {
global $CFG;
if (empty($CFG->guestroleid)) {
if ($roles = get_roles_with_capability('moodle/legacy:guest', CAP_ALLOW)) {
$guestrole = array_shift($roles); // Pick the first one
set_config('guestroleid', $guestrole->id);
return $guestrole;
} else {
debugging('Can not find any guest role!');
return false;
}
} else {
if ($guestrole = get_record('role','id', $CFG->guestroleid)) {
return $guestrole;
} else {
//somebody is messing with guest roles, remove incorrect setting and try to find a new one
set_config('guestroleid', '');
return get_guest_role();
}
}
}
/**
* This functions get all the course categories in proper order
* (!)note this only gets course category contexts, and not the site
* context
* @param object $context
* @return array of contextids
*/
function get_parent_cats($context) {
global $COURSE;
switch ($context->contextlevel) {
// a category can be the parent of another category
// there is no limit of depth in this case
case CONTEXT_COURSECAT:
static $categoryparents = null; // cache for parent categories
if (!isset($categoryparents)) {
$categoryparents = array();
}
if (array_key_exists($context->instanceid, $categoryparents)) {
return $categoryparents[$context->instanceid];
}
if (!$cat = get_record('course_categories','id',$context->instanceid)) {
//error?
return array();
}
$parents = array();
while (!empty($cat->parent)) {
if (!$catcontext = get_context_instance(CONTEXT_COURSECAT, $cat->parent)) {
debugging('Incorrect category parent');
break;
}
$parents[] = $catcontext->id;
$cat = get_record('course_categories','id',$cat->parent);
}
return $categoryparents[$context->instanceid] = array_reverse($parents);
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:
static $courseparents = null; // cache course parents
if (!isset($courseparents)) {
$courseparents = array();
}
if (array_key_exists($context->instanceid, $courseparents)) {
return $courseparents[$context->instanceid];
}
if (count($courseparents) > 1000) {
$courseparents = array(); // max cache size when looping through thousands of courses
}
if ($context->instanceid == SITEID) {
return $courseparents[$context->instanceid] = array(); // frontpage course does not have parent cats
}
if ($context->instanceid == $COURSE->id) {
$course = $COURSE;
} else if (!$course = get_record('course', 'id', $context->instanceid)) {
//error?
return array();;
}
if (empty($course->category)) {
// this should not happen
return $courseparents[$context->instanceid] = array();
}
if (!$catcontext = get_context_instance(CONTEXT_COURSECAT, $course->category)) {
debugging('Incorect course category');
return array();;
}
return $courseparents[$context->instanceid] = array_merge(get_parent_cats($catcontext), array($catcontext->id)); //recursion :-)
break;
default:
// something is very wrong!
return array();
break;
}
}
function has_capability($capability, $context=NULL, $userid=NULL, $doanything=true) {
global $USER, $CONTEXT, $ACCESS, $CFG, $DIRTYCONTEXTS;
/// Make sure we know the current context
if (empty($context)) { // Use default CONTEXT if none specified
if (empty($CONTEXT)) {
return false;
} else {
$context = $CONTEXT;
}
}
if (empty($CONTEXT)) {
$CONTEXT = $context;
}
if (is_null($userid) || $userid===0) {
$userid = $USER->id;
}
$contexts = array();
$basepath = '/' . SYSCONTEXTID;
if (empty($context->path)) {
$contexts[] = SYSCONTEXTID;
$context->path = $basepath;
if (isset($context->id) && $context->id ==! SYSCONTEXTID) {
$contexts[] = $context->id;
$context->path .= '/' . $context->id;
}
} else {
$contexts = explode('/', $context->path);
array_shift($contexts);
}
if ($USER->id === 0 && !isset($USER->access)) {
load_all_capabilities();
}
if (defined('FULLME') && FULLME === 'cron' && !isset($USER->access)) {
//
// In cron, some modules setup a 'fake' $USER,
// ensure we load the appropriate accessdata.
// Also: set $DIRTYCONTEXTS to empty
//
if (!isset($ACCESS)) {
$ACCESS = array();
}
if (!isset($ACCESS[$userid])) {
load_user_accessdata($userid);
}
$USER->access = $ACCESS[$userid];
$DIRTYCONTEXTS = array();
}
// Careful check for staleness...
$clean = true;
if (!isset($DIRTYCONTEXTS)) {
// Load dirty contexts list
$DIRTYCONTEXTS = get_dirty_contexts($USER->access['time']);
// Check basepath only once, when
// we load the dirty contexts...
if (isset($DIRTYCONTEXTS->{$basepath})) {
// sitewide change, dirty
$clean = false;
}
}
// Check for staleness in the whole parenthood
if ($clean && !is_contextpath_clean($context->path, $DIRTYCONTEXTS)) {
$clean = false;
}
if (!$clean) {
// reload all capabilities - preserving loginas, roleswitches, etc
// and then cleanup any marks of dirtyness... at least from our short
// term memory! :-)
reload_all_capabilities();
$DIRTYCONTEXTS = array();
$clean = true;
}
// divulge how many times we are called
//// error_log("has_capability: id:{$context->id} path:{$context->path} userid:$userid cap:$capability");
if ($USER->id === $userid) {
//
// For the logged in user, we have $USER->access
// which will have all RAs and caps preloaded for
// course and above contexts.
//
// Contexts below courses && contexts that do not
// hang from courses are loaded into $USER->access
// on demand, and listed in $USER->access[loaded]
//
if ($context->contextlevel <= CONTEXT_COURSE) {
// Course and above are always preloaded
return has_cap_fad($capability, $context,
$USER->access, $doanything);
}
// Load it as needed
if (!path_inaccessdata($context->path,$USER->access)) {
error_log("loading access for context {$context->path} for $capability at {$context->contextlevel} {$context->id}");
// $bt = debug_backtrace();
// error_log("bt {$bt[0]['file']} {$bt[0]['line']}");
$USER->access = get_user_access_bycontext($USER->id, $context,
$USER->access);
}
return has_cap_fad($capability, $context,
$USER->access, $doanything);
}
if (!isset($ACCESS)) {
$ACCESS = array();
}
if (!isset($ACCESS[$userid])) {
load_user_accessdata($userid);
}
return has_cap_fad($capability, $context,
$ACCESS[$userid], $doanything);
}
function get_course_from_path ($path) {
// assume that nothing is more than 1 course deep
if (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
return $matches[1];
}
return false;
}
function path_inaccessdata($path, $ad) {
// assume that contexts hang from sys or from a course
// this will only work well with stuff that hangs from a course
if (in_array($path, $ad['loaded'], true)) {
error_log("found it!");
return true;
}
$base = '/' . SYSCONTEXTID;
while (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
$path = $matches[1];
if ($path === $base) {
return false;
}
if (in_array($path, $ad['loaded'], true)) {
return true;
}
}
return false;
}
/*
* Walk the accessdata array and return true/false.
* Deals with prohibits, roleswitching, aggregating
* capabilities, etc.
*
* The main feature of here is being FAST and with no
* side effects.
*
* Notes:
*
* Switch Roles exits early
* -----------------------
* cap checks within a switchrole need to exit early
* in our bottom up processing so they don't "see" that
* there are real RAs that can do all sorts of things.
*
* Switch Role merges with default role
* ------------------------------------
* If you are a teacher in course X, you have at least
* teacher-in-X + defaultloggedinuser-sitewide. So in the
* course you'll have techer+defaultloggedinuser.
* We try to mimic that in switchrole.
*
* "Guest default role" exception
* ------------------------------
*
* See MDL-7513 and $ignoreguest below for details.
*
* The rule is that
*
* IF we are being asked about moodle/legacy:guest
* OR moodle/course:view
* FOR a real, logged-in user
* AND we reached the top of the path in ra and rdef
* AND that role has moodle/legacy:guest === 1...
* THEN we act as if we hadn't seen it.
*
*
* To Do:
*
* - Document how it works
* - Rewrite in ASM :-)
*
*/
function has_cap_fad($capability, $context, $ad, $doanything) {
global $CFG;
$path = $context->path;
// build $contexts as a list of "paths" of the current
// contexts and parents with the order top-to-bottom
$contexts = array($path);
while (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
$path = $matches[1];
array_unshift($contexts, $path);
}
$ignoreguest = false;
if (isset($ad['dr'])
&& ($capability == 'moodle/course:view'
|| $capability == 'moodle/legacy:guest')) {
// At the base, ignore rdefs where moodle/legacy:guest
// is set
$ignoreguest = $ad['dr'];
}
$cc = count($contexts);
$can = false;
//
// role-switches loop
//
if (isset($ad['rsw'])) {
// check for isset() is fast
// empty() is slow...
if (empty($ad['rsw'])) {
unset($ad['rsw']); // keep things fast and unambiguous
break;
}
// From the bottom up...
for ($n=$cc-1;$n>=0;$n--) {
$ctxp = $contexts[$n];
if (isset($ad['rsw'][$ctxp])) {
// Found a switchrole assignment
// check for that role _plus_ the default user role
$ras = array($ad['rsw'][$ctxp],$CFG->defaultuserroleid);
for ($rn=0;$rn<2;$rn++) {
$roleid = $ras[$rn];
// Walk the path for capabilities
// from the bottom up...
for ($m=$cc-1;$m>=0;$m--) {
$capctxp = $contexts[$m];
if (isset($ad['rdef']["{$capctxp}:$roleid"][$capability])) {
$perm = $ad['rdef']["{$capctxp}:$roleid"][$capability];
if ($perm === CAP_PROHIBIT) {
return false;
} else {
$can += $perm;
}
}
}
}
// As we are dealing with a switchrole,
// we return _here_, do _not_ walk up
// the hierarchy any further
if ($can < 1) {
if ($doanything) {
// didn't find it as an explicit cap,
// but maybe the user candoanything in this context...
return has_cap_fad('moodle/site:doanything', $context,
$ad, false);
} else {
return false;
}
} else {
return true;
}
}
}
}
//
// Main loop for normal RAs
// From the bottom up...
//
for ($n=$cc-1;$n>=0;$n--) {
$ctxp = $contexts[$n];
if (isset($ad['ra'][$ctxp])) {
// Found role assignments on this leaf
$ras = $ad['ra'][$ctxp];
$rc = count($ras);
for ($rn=0;$rn<$rc;$rn++) {
$roleid = $ras[$rn];
// Walk the path for capabilities
// from the bottom up...
for ($m=$cc-1;$m>=0;$m--) {
$capctxp = $contexts[$m];
// ignore some guest caps
// at base ra and rdef
if ($ignoreguest == $roleid
&& $n === 0
&& $m === 0
&& isset($ad['rdef']["{$capctxp}:$roleid"]['moodle/legacy:guest'])
&& $ad['rdef']["{$capctxp}:$roleid"]['moodle/legacy:guest'] > 0) {
continue;
}
if (isset($ad['rdef']["{$capctxp}:$roleid"][$capability])) {
$perm = $ad['rdef']["{$capctxp}:$roleid"][$capability];
if ($perm === CAP_PROHIBIT) {
return false;
} else {
$can += $perm;
}
}
}
}
}
}
if ($can < 1) {
if ($doanything) {
// didn't find it as an explicit cap,
// but maybe the user candoanything in this context...
return has_cap_fad('moodle/site:doanything', $context,
$ad, false);
} else {
return false;
}
} else {
return true;
}
}
function aggr_roles_fad($context, $ad) {
$path = $context->path;
// build $contexts as a list of "paths" of the current
// contexts and parents with the order top-to-bottom
$contexts = array($path);
while (preg_match('!^(/.+)/\d+$!', $path, $matches)) {
$path = $matches[1];
array_unshift($contexts, $path);
}
$cc = count($contexts);
$roles = array();
// From the bottom up...
for ($n=$cc-1;$n>=0;$n--) {
$ctxp = $contexts[$n];
if (isset($ad['ra'][$ctxp]) && count($ad['ra'][$ctxp])) {
// Found assignments on this leaf
$addroles = $ad['ra'][$ctxp];
$roles = array_merge($roles, $addroles);
}
}
return array_unique($roles);
}
/**
* 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, $CFG;
/// If the current user is not logged in, then make sure they are (if needed)
if (is_null($userid) && !isset($USER->access)) {
if ($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);
}
}
/**
* Cheks if current user has allowed permission for any of submitted capabilities
* in given or child contexts.
* @param object $context - a context object (record from context table)
* @param array $capabilitynames array of strings, capability names
* @return boolean
*/
function has_capability_including_child_contexts($context, $capabilitynames) {
global $USER;
foreach ($capabilitynames as $capname) {
if (has_capability($capname, $context)) {
return true;
}
}
if ($children = get_child_contexts($context)) {
foreach ($capabilitynames as $capname) {
foreach ($children as $child) {
if (isset($USER->capabilities[$child][$capname]) and $USER->capabilities[$child][$capname] > 0) {
// extra check for inherited prevent and prohibit
if (has_capability($capname, get_context_instance_by_id($child), $USER->id, false)) {
return true;
}
}
}
}
}
return false;
}
/*
* Get an array of courses (with magic extra bits)
* where the accessdata and in DB enrolments show
* that the cap requested is available.
*
* The main use is for get_my_courses().
*
* Notes
*
* - $fields is an array of fieldnames to ADD
* so name the fields you really need, which will
* be added and uniq'd
*
* - the course records have $c->context which is a fully
* valid context object. Saves you a query per course!
*
* - the course records have $c->categorypath to make
* category lookups cheap
*
* - current implementation is split in -
*
* - if the user has the cap systemwide, stupidly
* grab *every* course for a capcheck. This eats
* a TON of bandwidth, specially on large sites
* with separate DBs...
*
* - otherwise, fetch "likely" courses with a wide net
* that should get us _cheaply_ at least the courses we need, and some
* we won't - we get courses that...
* - are in a category where user has the cap
* - or where use has a role-assignment (any kind)
* - or where the course has an override on for this cap
*
* - walk the courses recordset checking the caps oneach one
* the checks are all in memory and quite fast
* (though we could implement a specialised variant of the
* has_cap_fad() code to speed it up)
*
* @param string $capability - name of the capability
* @param array $accessdata - access session array
* @param bool $doanything - if false, ignore do anything
* @param string $sort - sorting fields - prefix each fieldname with "c."
* @param array $fields - additional fields you are interested in...
* @param int $limit - set if you want to limit the number of courses
* @return array $courses - ordered array of course objects - see notes above
*
*/
function get_user_courses_bycap($userid, $cap, $ad, $doanything, $sort='c.sortorder ASC', $fields=NULL, $limit=0) {
global $CFG;
// Slim base fields, let callers ask for what they need...
$basefields = array('id', 'sortorder', 'shortname', 'idnumber');
if (!is_null($fields)) {
$fields = array_merge($basefields, $fields);
$fields = array_unique($fields);
} else {
$fields = $basefields;
}
$coursefields = 'c.' .join(',c.', $fields);
$sysctx = get_context_instance(CONTEXT_SYSTEM);
if (has_cap_fad($cap, $sysctx, $ad, $doanything)) {
//
// Apparently the user has the cap sitewide, so walk *every* course
// (the cap checks are moderately fast, but this moves massive bandwidth w the db)
// Yuck.
//
$sql = "SELECT $coursefields,
ctx.id AS ctxid, ctx.path AS ctxpath, ctx.depth as ctxdepth,
cc.path AS categorypath
FROM {$CFG->prefix}course c
JOIN {$CFG->prefix}course_categories cc
ON c.category=cc.id
JOIN {$CFG->prefix}context ctx
ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
ORDER BY $sort ";
$rs = get_recordset_sql($sql);
} else {
//
// narrow down where we have the caps to a few contexts
// this will be a combination of
// - categories where we have the rights
// - courses where we have an explicit enrolment OR that have an override
//
$sql = "SELECT ctx.*
FROM {$CFG->prefix}context ctx
WHERE ctx.contextlevel=".CONTEXT_COURSECAT."
ORDER BY ctx.depth";
$rs = get_recordset_sql($sql);
$catpaths = array();
if ($rs->RecordCount()) {
while ($catctx = rs_fetch_next_record($rs)) {
if ($catctx->path != ''
&& has_cap_fad($cap, $catctx, $ad, $doanything)) {
$catpaths[] = $catctx->path;
}
}
}
rs_close($rs);
$catclause = '';
if (count($catpaths)) {
$cc = count($catpaths);
for ($n=0;$n<$cc;$n++) {
$catpaths[$n] = "ctx.path LIKE '{$catpaths[$n]}/%'";
}
$catclause = 'OR (' . join(' OR ', $catpaths) .')';
}
unset($catpaths);
$capany = '';
if ($doanything) {
$capany = " OR rc.capability='moodle/site:doanything'";
}
//
// Note here that we *have* to have the compound clauses
// in the LEFT OUTER JOIN condition for them to return NULL
// appropriately and narrow things down...
//
$sql = "SELECT $coursefields,
ctx.id AS ctxid, ctx.path AS ctxpath, ctx.depth as ctxdepth,
cc.path AS categorypath
FROM {$CFG->prefix}course c
JOIN {$CFG->prefix}course_categories cc
ON c.category=cc.id
JOIN {$CFG->prefix}context ctx
ON (c.id=ctx.instanceid AND ctx.contextlevel=".CONTEXT_COURSE.")
LEFT OUTER JOIN {$CFG->prefix}role_assignments ra
ON (ra.contextid=ctx.id AND ra.userid=$userid)
LEFT OUTER JOIN {$CFG->prefix}role_capabilities rc
ON (rc.contextid=ctx.id AND (rc.capability='$cap' $capany))
WHERE ra.id IS NOT NULL
OR rc.id IS NOT NULL
$catclause
ORDER BY $sort ";
$rs = get_recordset_sql($sql);
}
$courses = array();
$cc = 0; // keep count
if ($rs->RecordCount()) {
while ($c = rs_fetch_next_record($rs)) {
// build the context obj
$c = make_context_subobj($c);
if (has_cap_fad($cap, $c->context, $ad, $doanything)) {
$courses[] = $c;
if ($limit > 0 && $cc++ > $limit) {
break;
}
}
}
}
rs_close($rs);
return $courses;
}
/*
* Draft - use for the course participants list page
*
* Uses 1 DB query (cheap too - 2~7ms).
*
* TODO:
* - implement additional where clauses
* - sorting
* - get course participants list to use it!
*
* returns a users array, both sorted _and_ keyed
* on id (as get_my_courses() does)
*
* as a bonus, every user record comes with its own
* personal context, as our callers need it straight away
* {save 1 dbquery per user! yay!}
*
*/
function get_context_users_byrole ($context, $roleid, $fields=NULL, $where=NULL, $sort=NULL, $limit=0) {
global $CFG;
// Slim base fields, let callers ask for what they need...