moodle/search/documents/chat_document.php

328 lines
13 KiB
PHP

<?php
/**
* Global Search Engine for Moodle
*
* @package search
* @category core
* @subpackage document_wrappers
* @author Valery Fremaux [valery.fremaux@club-internet.fr] > 1.8
* @contributor Tatsuva Shirai 20090530
* @date 2008/03/31
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
* @version Moodle 2.0
*
* document handling for chat activity module
* This file contains the mapping between a chat history and it's indexable counterpart,
*
* Functions for iterating and retrieving the necessary records are now also included
* in this file, rather than mod/chat/lib.php
*
*/
/**
* includes and requires
*/
require_once($CFG->dirroot.'/search/documents/document.php');
require_once($CFG->dirroot.'/mod/chat/lib.php');
/**
* a class for representing searchable information
*
*/
class ChatTrackSearchDocument extends SearchDocument {
/**
* constructor
*/
public function __construct(&$chatsession, $chat_id, $chat_module_id, $course_id, $group_id, $context_id) {
// generic information; required
$doc->docid = $chat_id.'-'.$chatsession['sessionstart'].'-'.$chatsession['sessionend'];
$doc->documenttype = SEARCH_TYPE_CHAT;
$doc->itemtype = 'session';
$doc->contextid = $context_id;
$duration = $chatsession['sessionend'] - $chatsession['sessionstart'];
// we cannot call userdate with relevant locale at indexing time.
$doc->title = get_string('chatreport', 'chat').' '.get_string('openedon', 'search').' TT_'.$chatsession['sessionstart'].'_TT ('.get_string('duration', 'search').' : '.get_string('numseconds', '', $duration).')';
$doc->date = $chatsession['sessionend'];
//remove '(ip.ip.ip.ip)' from chat author list
$doc->author = preg_replace('/\(.*?\)/', '', $chatsession['authors']);
$doc->contents = $chatsession['content'];
$doc->url = chat_make_link($chat_module_id, $chatsession['sessionstart'], $chatsession['sessionend']);
// module specific information; optional
$data->chat = $chat_id;
// construct the parent class
parent::__construct($doc, $data, $course_id, $group_id, 0, 'mod/'.SEARCH_TYPE_CHAT);
}
}
/**
* constructs a valid link to a chat content
* @param cm_id the chat course module
* @param int $start the start time of the session
* @param int $end th end time of the session
* @uses $CFG
* @return a well formed link to session display
*/
function chat_make_link($cm_id, $start, $end) {
global $CFG;
return $CFG->wwwroot.'/mod/chat/report.php?id='.$cm_id.'&amp;start='.$start.'&amp;end='.$end;
}
/**
* fetches all the records for a given session and assemble them as a unique track
* we revamped here the code of report.php for making sessions, but without any output.
* note that we should collect sessions "by groups" if $groupmode is SEPARATEGROUPS.
* @param int $chat_id the database
* @param int $fromtime
* @param int $totime
* @uses $CFG, $DB
* @return an array of objects representing the chat sessions.
*/
function chat_get_session_tracks($chat_id, $fromtime = 0, $totime = 0) {
global $CFG, $DB;
$chat = $DB->get_record('chat', array('id' => $chat_id));
$course = $DB->get_record('course', array('id' => $chat->course));
$coursemodule = $DB->get_field('modules', 'id', array('name' => 'data'));
$cm = $DB->get_record('course_modules', array('course' => $course->id, 'module' => $coursemodule, 'instance' => $chat->id));
if (isset($cm->groupmode) && empty($course->groupmodeforce)) {
$groupmode = $cm->groupmode;
} else {
$groupmode = $course->groupmode;
}
$fromtimeclause = ($fromtime) ? "AND timestamp >= {$fromtime}" : '';
$totimeclause = ($totime) ? "AND timestamp <= {$totime}" : '';
$tracks = array();
$messages = $DB->get_records_select('chat_messages', "chatid = :chatid :from :to", array('chatid' => $chat_id, 'from' => $fromtimeclause, 'to' => $totimeclause), 'timestamp DESC');
if ($messages){
// splits discussions against groups
$groupedMessages = array();
if ($groupmode != SEPARATEGROUPS){
foreach($messages as $aMessage){
$groupedMessages[$aMessage->groupid][] = $aMessage;
}
} else {
$groupedMessages[-1] = &$messages;
}
$sessiongap = 5 * 60; // 5 minutes silence means a new session
$sessionend = 0;
$sessionstart = 0;
$sessionusers = array();
$lasttime = time();
foreach ($groupedMessages as $groupId => $messages) { // We are walking BACKWARDS through the messages
$messagesleft = count($messages);
foreach ($messages as $message) { // We are walking BACKWARDS through the messages
$messagesleft --; // Countdown
if ($message->system) {
continue;
}
// we are within a session track
if ((($lasttime - $message->timestamp) < $sessiongap) and $messagesleft) { // Same session
if (count($tracks) > 0){
if ($message->userid) { // Remember user and count messages
$tracks[count($tracks) - 1]->sessionusers[$message->userid] = $message->userid;
// update last track (if exists) record appending content (remember : we go backwards)
}
$tracks[count($tracks) - 1]->content .= ' '.$message->message;
$tracks[count($tracks) - 1]->sessionstart = $message->timestamp;
}
} else {
// we initiate a new session track (backwards)
$track = new stdClass();
$track->sessionend = $message->timestamp;
$track->sessionstart = $message->timestamp;
$track->content = $message->message;
// reset the accumulator of users
$track->sessionusers = array();
$track->sessionusers[$message->userid] = $message->userid;
$track->groupid = $groupId;
$tracks[] = $track;
}
$lasttime = $message->timestamp;
}
}
}
return $tracks;
}
/**
* part of search engine API
* @uses $DB
*
*/
function chat_iterator() {
global $DB;
$chatrooms = $DB->get_records('chat');
return $chatrooms;
}
/**
* part of search engine API
* @uses $DB
* @param reference $chat
*
*/
function chat_get_content_for_index(&$chat) {
global $DB;
$documents = array();
$course = $DB->get_record('course', array('id' => $chat->course));
$coursemodule = $DB->get_field('modules', 'id', array('name' => 'chat'));
$cm = $DB->get_record('course_modules', array('course' => $chat->course, 'module' => $coursemodule, 'instance' => $chat->id));
if ($cm){
$context = get_context_instance(CONTEXT_MODULE, $cm->id);
// getting records for indexing
$sessionTracks = chat_get_session_tracks($chat->id);
if ($sessionTracks){
foreach($sessionTracks as $aTrackId => $aTrack) {
foreach($aTrack->sessionusers as $aUserId){
$user = $DB->get_record('user', array('id' => $aUserId));
$aTrack->authors = ($user) ? fullname($user) : '' ;
$documents[] = new ChatTrackSearchDocument(get_object_vars($aTrack), $chat->id, $cm->id, $chat->course, $aTrack->groupid, $context->id);
}
}
}
return $documents;
}
return array();
}
/**
* returns a single data search document based on a chat_session id
* chat session id is a text composite identifier made of :
* - the chat id
* - the timestamp when the session starts
* - the timestamp when the session ends
* @uses $DB
* @param id the multipart chat session id
* @param itemtype the type of information (session is the only type)
*/
function chat_single_document($id, $itemtype) {
global $DB;
list($chat_id, $sessionstart, $sessionend) = explode('-', $id);
$chat = $DB->get_record('chat', array('id' => $chat_id));
$course = $DB->get_record('course', array('id' => $chat->course));
$coursemodule = $DB->get_field('modules', 'id', array('name' => 'chat'));
$cm = $DB->get_record('course_modules', array('course' => $course->id, 'module' => $coursemodule, 'instance' => $chat->id));
if ($cm){
$context = get_context_instance(CONTEXT_MODULE, $cm->id);
// should be only one
$tracks = chat_get_session_tracks($chat->id, $sessionstart, $sessionstart);
if ($tracks){
$aTrack = $tracks[0];
$document = new ChatTrackSearchDocument(get_object_vars($aTrack), $chat_id, $cm->id, $chat->course, $aTrack->groupid, $context->id);
return $document;
}
}
return null;
}
/**
* dummy delete function that packs id with itemtype.
* this was here for a reason, but I can't remember it at the moment.
*
*/
function chat_delete($info, $itemtype) {
$object->id = $info;
$object->itemtype = $itemtype;
return $object;
}
/**
* returns the var names needed to build a sql query for addition/deletions
* // TODO chat indexable records are virtual. Should proceed in a special way
*/
function chat_db_names() {
//[primary id], [table name], [time created field name], [time modified field name]
return null;
}
/**
* this function handles the access policy to contents indexed as searchable documents. If this
* function does not exist, the search engine assumes access is allowed.
* When this point is reached, we already know that :
* - user is legitimate in the surrounding context
* - user may be guest and guest access is allowed to the module
* - the function may perform local checks within the module information logic
* @param string $path the access path to the module script code
* @param string $itemtype the information subclassing (usefull for complex modules, defaults to 'standard')
* @param int $this_id the item id within the information class denoted by entry_type. In chats, this id
* points out a session history which is a close sequence of messages.
* @param int $user the user record denoting the user who searches
* @param int $group_id the current group used by the user when searching
* @uses $CFG, $DB
* @return true if access is allowed, false elsewhere
*/
function chat_check_text_access($path, $itemtype, $this_id, $user, $group_id, $context_id){
global $CFG, $DB;
include_once("{$CFG->dirroot}/{$path}/lib.php");
list($chat_id, $sessionstart, $sessionend) = explode('-', $this_id);
// get the chat session and all related stuff
$chat = $DB->get_record('chat', array('id' => $chat_id));
$context = $DB->get_record('context', array('id' => $context_id));
$cm = $DB->get_record('course_modules', array('id' => $context->instanceid));
if (empty($cm)) return false; // Shirai 20090530 - MDL19342 - course module might have been delete
if (!$cm->visible and !has_capability('moodle/course:viewhiddenactivities', $context)){
if (!empty($CFG->search_access_debug)) echo "search reject : hidden chat ";
return false;
}
//group consistency check : checks the following situations about groups
// trap if user is not same group and groups are separated
$course = $DB->get_record('course', array('id' => $chat->course));
if (isset($cm->groupmode) && empty($course->groupmodeforce)) {
$groupmode = $cm->groupmode;
} else {
$groupmode = $course->groupmode;
}
if (($groupmode == SEPARATEGROUPS) && !ismember($group_id) && !has_capability('moodle/site:accessallgroups', $context)){
if (!empty($CFG->search_access_debug)) echo "search reject : chat element is in separated group ";
return false;
}
//ownership check : checks the following situations about user
// trap if user is not owner and has cannot see other's entries
// TODO : typically may be stored into indexing cache
if (!has_capability('mod/chat:readlog', $context)){
if (!empty($CFG->search_access_debug)) echo "search reject : cannot read past sessions ";
return false;
}
return true;
}
/**
* this call back is called when displaying the link for some last post processing
* @uses $CFG
* @param string $title
*
*/
function chat_link_post_processing($title){
global $CFG;
setLocale(LC_TIME, substr(current_language(), 0, 2));
$title = preg_replace('/TT_(.*)_TT/e', "userdate(\\1)", $title);
if ($CFG->block_search_utf8dir){
return mb_convert_encoding($title, 'UTF-8', 'auto');
}
return mb_convert_encoding($title, 'auto', 'UTF-8');
}
?>