/**
* Internal method. Queries for a number of forums, including additional
* data about unread posts etc. Returns the database result.
* @param array $cmids If specified, array of course-module IDs of desired
* forums
* @param object $course If specified, course object
* @param int $userid User ID, 0 = current user
* @param int $unread Type of unread data to obtain (UNREAD_xx constant).
* @param array $groups Array of group IDs to which the given user belongs
* (may be null if unread data not required)
* @param array $aagforums Array of forums in which the user has
* 'access all groups' (may be null if unread data not required)
* @param array $viewhiddenforums Array of forums in which the user has
* 'view hidden discussions' (may be null if unread data not required)
* @return array Array of row objects
*/
private static function query_forums($cmids = array(), $course = null, $userid, $unread, $groups, $aagforums, $viewhiddenforums)
{
global $CFG, $USER;
if (!count($cmids) && !$course) {
throw new forum_exception("forum::query_forums requires course id or cmids");
}
if (count($cmids)) {
$conditions = "cm.id " . forum_utils::in_or_equals($cmids);
} else {
$conditions = "f.course = {$course->id}";
}
$singleforum = count($cmids) == 1 ? reset($cmids) : false;
$inviewhiddenforums = forum_utils::in_or_equals($viewhiddenforums);
// This array of additional results is used later if combining
// standard results with single-forum calls.
$plusresult = array();
// For read tracking, we get a count of total number of posts in
// forum, and total number of read posts in the forum (this
// is so we can display the number of UNread posts, but the query
// works that way around because it will return 0 if no read
// information is stored).
if ($unread != self::UNREAD_NONE && forum::enabled_read_tracking()) {
// Work out when unread status ends
$endtime = time() - $CFG->forumng_readafterdays * 24 * 3600;
if (!$userid) {
$userid = $USER->id;
}
$ingroups = forum_utils::in_or_equals($groups);
$inaagforums = forum_utils::in_or_equals($aagforums);
$restrictionsql = '';
if ($singleforum) {
// If it is for a single forum, get the restriction from the
// forum type
$forum = forum::get_from_cmid($singleforum, forum::CLONE_DIRECT);
$type = $forum->get_type();
if ($type->has_unread_restriction()) {
$value = $type->get_unread_restriction_sql($forum);
if ($value) {
$restrictionsql = 'AND ' . $value;
}
}
} else {
// When it is not for a single forum, we can only group together
// results for types that do not place restrictions on the
// unread count.
$modinfo = self::get_modinfo_special($course, $cmids);
$okayids = array();
if (array_key_exists('forumng', $modinfo->instances)) {
foreach ($modinfo->instances['forumng'] as $info) {
if (count($cmids) && !in_array($info->id, $cmids)) {
continue;
}
$type = self::get_type_from_modinfo_info($info);
if (forum_type::get_new($type)->has_unread_restriction()) {
// This one's a problem! Do it individually
$problemresults = self::query_forums(array($info->id), null, $userid, $unread, $groups, $aagforums, $viewhiddenforums);
foreach ($problemresults as $problemresult) {
$plusresult[$problemresult->f_id] = $problemresult;
}
} else {
$okayids[] = $info->id;
}
}
}
if (count($okayids) == 0) {
// There are no 'normal' forums, so return result so far
// after sorting it
uasort($plusresult, 'forum::sort_forum_result');
return $plusresult;
} else {
// Fall through to normal calculation, but change conditions
// to include only the 'normal' forums
$conditions .= " AND cm.id " . forum_utils::in_or_equals($okayids);
}
}
// NOTE fpfirst is used only by forum types, not here
$now = time();
$sharedquerypart = "\nFROM\n {$CFG->prefix}forumng_discussions fd\n INNER JOIN {$CFG->prefix}forumng_posts fplast ON fd.lastpostid = fplast.id\n INNER JOIN {$CFG->prefix}forumng_posts fpfirst ON fd.postid = fpfirst.id\n LEFT JOIN {$CFG->prefix}forumng_read fr ON fd.id = fr.discussionid AND fr.userid={$userid}\nWHERE\n fd.forumid=f.id AND fplast.modified>{$endtime}\n AND (\n (fd.groupid IS NULL)\n OR (fd.groupid {$ingroups})\n OR cm.groupmode=" . VISIBLEGROUPS . "\n OR (fd.forumid {$inaagforums})\n )\n AND fd.deleted=0\n AND (\n ((fd.timestart=0 OR fd.timestart <= {$now})\n AND (fd.timeend=0 OR fd.timeend > {$now}))\n OR (fd.forumid {$inviewhiddenforums})\n )\n AND ((fplast.edituserid IS NOT NULL AND fplast.edituserid<>{$userid})\n OR fplast.userid<>{$userid})\n AND (fr.time IS NULL OR fplast.modified>fr.time)\n {$restrictionsql}";
// Note: There is an unusual case in which this number can
// be inaccurate. It is to do with ignoring messages the user
// posted. We consider a discussion as 'not unread' if the last
// message is by current user. In actual fact, a discussion could
// contain unread messages if messages were posted by other users
// after this user viewed the forum last, but before they posted
// their reply. Since this should be an infrequent occurrence I
// believe this behaviour is acceptable.
if ($unread == self::UNREAD_BINARY && ($CFG->dbtype == 'postgres7' || $CFG->dbtype == 'mysql')) {
// Query to get 0/1 unread discussions count
$readtracking = "\n(SELECT\n COUNT(1)\nFROM (\n SELECT\n 1\n {$sharedquerypart}\n LIMIT 1) innerquery\n) AS f_hasunreaddiscussions";
} else {
// Query to get full unread discussions count
$readtracking = "\n(SELECT\n COUNT(1)\n{$sharedquerypart}\n) AS f_numunreaddiscussions";
}
} else {
$readtracking = "NULL AS numreadposts, NULL AS timeread";
}
$now = time();
$orderby = "LOWER(f.name)";
// Main query. This retrieves:
// - Full forum fields
// - Basic course-module and course data (not whole tables)
// - Discussion count
// - Unread data, if enabled
// - User subscription data
$rs = get_recordset_sql($sql = "\nSELECT\n " . forum_utils::select_forum_fields('f') . ",\n " . forum_utils::select_course_module_fields('cm') . ",\n " . forum_utils::select_course_fields('c') . ",\n (SELECT COUNT(1)\n FROM {$CFG->prefix}forumng_discussions cfd\n WHERE cfd.forumid=f.id AND cfd.deleted=0\n AND (\n ((cfd.timestart=0 OR cfd.timestart <= {$now})\n AND (cfd.timeend=0 OR cfd.timeend > {$now}))\n OR (cfd.forumid {$inviewhiddenforums})\n )\n ) AS f_numdiscussions,\n {$readtracking}\nFROM\n {$CFG->prefix}forumng f\n INNER JOIN {$CFG->prefix}course_modules cm ON cm.instance=f.id\n AND cm.module=(SELECT id from {$CFG->prefix}modules WHERE name='forumng')\n INNER JOIN {$CFG->prefix}course c ON c.id=f.course\nWHERE\n {$conditions}\nORDER BY\n {$orderby}");
if (!$rs) {
throw new forum_exception("Failed to retrieve forums");
}
$result = recordset_to_array($rs);
rs_close($rs);
if (count($plusresult) > 0) {
foreach ($plusresult as $key => $value) {
$result[$key] = $value;
}
uasort($result, 'forum::sort_forum_result');
}
return $result;
}
