<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file adds support to rss feeds generation
*
* @package mod_forum
* @category rss
* @copyright 2001 Eloy Lafuente (stronk7) http://contiento.com
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
/* Include the core RSS lib */
require_once($CFG->libdir.'/rsslib.php');
/**
* Returns the path to the cached rss feed contents. Creates/updates the cache if necessary.
* @param stdClass $context the context
* @param array $args the arguments received in the url
* @return string the full path to the cached RSS feed directory. Null if there is a problem.
*/
function forum_rss_get_feed($context, $args) {
global $CFG, $DB, $USER;
$status = true;
//are RSS feeds enabled?
if (empty($CFG->forum_enablerssfeeds)) {
debugging('DISABLED (module configuration)');
return null;
}
$forumid = clean_param($args[3], PARAM_INT);
$cm = get_coursemodule_from_instance('forum', $forumid, 0, false, MUST_EXIST);
$modcontext = context_module::instance($cm->id);
//context id from db should match the submitted one
if ($context->id != $modcontext->id || !has_capability('mod/forum:viewdiscussion', $modcontext)) {
return null;
}
$forum = $DB->get_record('forum', array('id' => $forumid), '*', MUST_EXIST);
if (!rss_enabled_for_mod('forum', $forum)) {
return null;
}
//the sql that will retreive the data for the feed and be hashed to get the cache filename
list($sql, $params) = forum_rss_get_sql($forum, $cm);
// Hash the sql to get the cache file name.
$filename = rss_get_file_name($forum, $sql, $params);
$cachedfilepath = rss_get_file_full_name('mod_forum', $filename);
//Is the cache out of date?
$cachedfilelastmodified = 0;
if (file_exists($cachedfilepath)) {
$cachedfilelastmodified = filemtime($cachedfilepath);
}
// Used to determine if we need to generate a new RSS feed.
$dontrecheckcutoff = time() - 60; // Sixty seconds ago.
// If it hasn't been generated we need to create it.
// Otherwise, if it has been > 60 seconds since we last updated, check for new items.
if (($cachedfilelastmodified == 0) || (($dontrecheckcutoff > $cachedfilelastmodified) &&
forum_rss_newstuff($forum, $cm, $cachedfilelastmodified))) {
// Need to regenerate the cached version.
$result = forum_rss_feed_contents($forum, $sql, $params, $modcontext);
$status = rss_save_file('mod_forum', $filename, $result);
}
//return the path to the cached version
return $cachedfilepath;
}
/**
* Given a forum object, deletes all cached RSS files associated with it.
*
* @param stdClass $forum
*/
function forum_rss_delete_file($forum) {
rss_delete_file('mod_forum', $forum);
}
///////////////////////////////////////////////////////
//Utility functions
/**
* If there is new stuff in the forum since $time this returns true
* Otherwise it returns false.
*
* @param stdClass $forum the forum object
* @param stdClass $cm Course Module object
* @param int $time check for items since this epoch timestamp
* @return bool True for new items
*/
function forum_rss_newstuff($forum, $cm, $time) {
global $DB;
list($sql, $params) = forum_rss_get_sql($forum, $cm, $time);
return $DB->record_exists_sql($sql, $params);
}
/**
* Determines which type of SQL query is required, one for posts or one for discussions, and returns the appropriate query
*
* @param stdClass $forum the forum object
* @param stdClass $cm Course Module object
* @param int $time check for items since this epoch timestamp
* @return string the SQL query to be used to get the Discussion/Post details from the forum table of the database
*/
function forum_rss_get_sql($forum, $cm, $time=0) {
if ($forum->rsstype == 1) { // Discussion RSS
return forum_rss_feed_discussions_sql($forum, $cm, $time);
} else { // Post RSS
return forum_rss_feed_posts_sql($forum, $cm, $time);
}
}
/**
* Generates the SQL query used to get the Discussion details from the forum table of the database
*
* @param stdClass $forum the forum object
* @param stdClass $cm Course Module object
* @param int $newsince check for items since this epoch timestamp
* @return string the SQL query to be used to get the Discussion details from the forum table of the database
*/
function forum_rss_feed_discussions_sql($forum, $cm, $newsince=0) {
global $CFG, $DB, $USER;
$timelimit = '';
$modcontext = null;
$now = floor(time() / 60) * 60; // DB Cache Friendly.
$params = array();
$modcontext = context_module::instance($cm->id);
if (!empty($CFG->forum_enabletimedposts)) { /// Users must fulfill timed posts
if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {
$timelimit = " AND ((d.timestart <= :now1 AND (d.timeend = 0 OR d.timeend > :now2))";
$params['now1'] = $now;
$params['now2'] = $now;
if (isloggedin()) {
$timelimit .= " OR d.userid = :userid";
$params['userid'] = $USER->id;
}
$timelimit .= ")";
}
}
// Do we only want new posts?
if ($newsince) {
$params['newsince'] = $newsince;
$newsince = " AND p.modified > :newsince";
} else {
$newsince = '';
}
// Get group enforcing SQL.
$groupmode = groups_get_activity_groupmode($cm);
$currentgroup = groups_get_activity_group($cm);
list($groupselect, $groupparams) = forum_rss_get_group_sql($cm, $groupmode, $currentgroup, $modcontext);
// Add the groupparams to the params array.
$params = array_merge($params, $groupparams);
$forumsort = "d.timemodified DESC";
$postdata = "p.id AS postid, p.subject, p.created as postcreated, p.modified, p.discussion, p.userid, p.message as postmessage, p.messageformat AS postformat, p.messagetrust AS posttrust";
$userfieldsapi = \core_user\fields::for_userpic();
$userpicturefields = $userfieldsapi->get_sql('u', false, '', 'userid', false)->selects;
$sql = "SELECT $postdata, d.id as discussionid, d.name as discussionname, d.timemodified, d.usermodified, d.groupid,
d.timestart, d.timeend, $userpicturefields
FROM {forum_discussions} d
JOIN {forum_posts} p ON p.discussion = d.id
JOIN {user} u ON p.userid = u.id
WHERE d.forum = {$forum->id} AND p.parent = 0 AND p.deleted <> 1
$timelimit $groupselect $newsince
ORDER BY $forumsort";
return array($sql, $params);
}
/**
* Generates the SQL query used to get the Post details from the forum table of the database
*
* @param stdClass $forum the forum object
* @param stdClass $cm Course Module object
* @param int $newsince check for items since this epoch timestamp
* @return string the SQL query to be used to get the Post details from the forum table of the database
*/
function forum_rss_feed_posts_sql($forum, $cm, $newsince=0) {
global $USER;
$modcontext = context_module::instance($cm->id);
// Get group enforcement SQL.
$groupmode = groups_get_activity_groupmode($cm);
$currentgroup = groups_get_activity_group($cm);
$params = array();
list($groupselect, $groupparams) = forum_rss_get_group_sql($cm, $groupmode, $currentgroup, $modcontext);
// Add the groupparams to the params array.
$params = array_merge($params, $groupparams);
// Do we only want new posts?
if ($newsince) {
$params['newsince'] = $newsince;
$newsince = " AND p.modified > :newsince";
} else {
$newsince = '';
}
$canseeprivatereplies = has_capability('mod/forum:readprivatereplies', $modcontext);
if (!$canseeprivatereplies) {
$privatewhere = ' AND (p.privatereplyto = :currentuser1 OR p.userid = :currentuser2 OR p.privatereplyto = 0)';
$params['currentuser1'] = $USER->id;
$params['currentuser2'] = $USER->id;
} else {
$privatewhere = '';
}
$userfieldsapi = \core_user\fields::for_name();
$usernamefields = $userfieldsapi->get_sql('u', false, '', '', false)->selects;
$sql = "SELECT p.id AS postid,
d.id AS discussionid,
d.name AS discussionname,
d.groupid,
d.timestart,
d.timeend,
u.id AS userid,
$usernamefields,
p.subject AS postsubject,
p.message AS postmessage,
p.created AS postcreated,
p.messageformat AS postformat,
p.messagetrust AS posttrust,
p.parent as postparent
FROM {forum_discussions} d,
{forum_posts} p,
{user} u
WHERE d.forum = {$forum->id} AND
p.discussion = d.id AND p.deleted <> 1 AND
u.id = p.userid $newsince
$privatewhere
$groupselect
ORDER BY p.created desc";
return array($sql, $params);
}
/**
* Retrieve the correct SQL snippet for group-only forums
*
* @param stdClass $cm Course Module object
* @param int $groupmode the mode in which the forum's groups are operating
* @param bool $currentgroup true if the user is from the a group enabled on the forum
* @param stdClass $modcontext The context instance of the forum module
* @return string SQL Query for group details of the forum
*/
function forum_rss_get_group_sql($cm, $groupmode, $currentgroup, $modcontext=null) {
$groupselect = '';
$params = array();
if ($groupmode) {
if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {
if ($currentgroup) {
$groupselect = "AND (d.groupid = :groupid OR d.groupid = -1)";
$params['groupid'] = $currentgroup;
}
} else {
// Separate groups without access all.
if ($currentgroup) {
$groupselect = "AND (d.groupid = :groupid OR d.groupid = -1)";
$params['groupid'] = $currentgroup;
} else {
$groupselect = "AND d.groupid = -1";
}
}
}
return array($groupselect, $params);
}
/**
* This function return the XML rss contents about the forum
* It returns false if something is wrong
*
* @param stdClass $forum the forum object
* @param string $sql the SQL used to retrieve the contents from the database
* @param array $params the SQL parameters used
* @param object $context the context this forum relates to
* @return bool|string false if the contents is empty, otherwise the contents of the feed is returned
*
* @Todo MDL-31129 implement post attachment handling
*/
function forum_rss_feed_contents($forum, $sql, $params, $context) {
global $CFG, $DB, $USER;
$recs = $DB->get_recordset_sql($sql, $params, 0, $forum->rssarticles);
//set a flag. Are we displaying discussions or posts?
$isdiscussion = true;
if (!empty($forum->rsstype) && $forum->rsstype!=1) {
$isdiscussion = false;
}
if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {
throw new \moodle_exception('invalidcoursemodule');
}
$items = array();
foreach ($recs as $rec) {
$item = new stdClass();
$discussion = new stdClass();
$discussion->id = $rec->discussionid;
$discussion->groupid = $rec->groupid;
$discussion->timestart = $rec->timestart;
$discussion->timeend = $rec->timeend;
$post = null;
if (!$isdiscussion) {
$post = new stdClass();
$post->id = $rec->postid;
$post->parent = $rec->postparent;
$post->userid = $rec->userid;
}
if ($isdiscussion && !forum_user_can_see_discussion($forum, $discussion, $context)) {
// This is a discussion which the user has no permission to view
$item->title = get_string('forumsubjecthidden', 'forum');
$message = get_string('forumbodyhidden', 'forum');
$item->author = get_string('forumauthorhidden', 'forum');
} else if (!$isdiscussion && !forum_user_can_see_post($forum, $discussion, $post, $USER, $cm)) {
if (forum_user_can_see_post($forum, $discussion, $post, $USER, $cm, false)) {
// This is a post which the user has no permission to view.
$item->title = get_string('forumsubjecthidden', 'forum');
$message = get_string('forumbodyhidden', 'forum');
$item->author = get_string('forumauthorhidden', 'forum');
} else {
// This is a post which has been deleted.
$item->title = get_string('forumsubjectdeleted', 'mod_forum');
$message = get_string('forumbodydeleted', 'mod_forum');
$item->author = get_string('forumauthorhidden', 'forum');
}
} else {
// The user must have permission to view
if ($isdiscussion && !empty($rec->discussionname)) {
$item->title = format_string($rec->discussionname);
} else if (!empty($rec->postsubject)) {
$item->title = format_string($rec->postsubject);
} else {
//we should have an item title by now but if we dont somehow then substitute something somewhat meaningful
$item->title = format_string($forum->name.' '.userdate($rec->postcreated,get_string('strftimedatetimeshort', 'langconfig')));
}
$item->author = fullname($rec);
$message = file_rewrite_pluginfile_urls($rec->postmessage, 'pluginfile.php', $context->id,
'mod_forum', 'post', $rec->postid);
}
if ($isdiscussion) {
$item->link = $CFG->wwwroot."/mod/forum/discuss.php?d=".$rec->discussionid;
} else {
$item->link = $CFG->wwwroot."/mod/forum/discuss.php?d=".$rec->discussionid."&parent=".$rec->postid;
}
$item->description = format_text($message, $rec->postformat, [
'context' => $context,
'trusted' => $rec->posttrust,
]);
//TODO: MDL-31129 implement post attachment handling
/*if (!$isdiscussion) {
$post_file_area_name = str_replace('//', '/', "$forum->course/$CFG->moddata/forum/$forum->id/$rec->postid");
$post_files = get_directory_list("$CFG->dataroot/$post_file_area_name");
if (!empty($post_files)) {
$item->attachments = array();
}
}*/
$item->pubdate = $rec->postcreated;
$items[] = $item;
}
$recs->close();
// Create the RSS header.
$header = rss_standard_header(strip_tags(format_string($forum->name,true)),
$CFG->wwwroot."/mod/forum/view.php?f=".$forum->id,
format_string($forum->intro,true)); // TODO: fix format
// Now all the RSS items, if there are any.
$articles = '';
if (!empty($items)) {
$articles = rss_add_items($items);
}
// Create the RSS footer.
$footer = rss_standard_footer();
return $header . $articles . $footer;
}