Proyectos de Subversion Moodle

<?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('privacy:request:delete:post:subject', 'mod_forum');

                    $message = get_string('privacy:request:delete:post:subject', '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;

}