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   1  <?php
   2  /**
   3  * Global Search Engine for Moodle
   4  *
   5  * @package search
   6  * @category core
   7  * @subpackage document_wrappers
   8  * @author Michael Campanis (mchampan) [cynnical@gmail.com], Valery Fremaux [valery.fremaux@club-internet.fr] > 1.8
   9  * @date 2008/03/31
  10  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  11  *
  12  * document handling for forum activity module
  13  * This file contains the mapping between a forum post and it's indexable counterpart,
  14  *
  15  * Functions for iterating and retrieving the necessary records are now also included
  16  * in this file, rather than mod/forum/lib.php
  17  *
  18  */
  19  
  20  /**
  21  * includes and requires
  22  */
  23  require_once("$CFG->dirroot/search/documents/document.php");
  24  require_once("$CFG->dirroot/mod/forum/lib.php");
  25  
  26  /** 
  27  * a class for representing searchable information
  28  * 
  29  */
  30  class ForumSearchDocument extends SearchDocument {
  31  
  32      /**
  33      * constructor
  34      */
  35      public function __construct(&$post, $forum_id, $course_id, $itemtype, $context_id) {
  36          // generic information
  37          $doc->docid        = $post['id'];
  38          $doc->documenttype = SEARCH_TYPE_FORUM;
  39          $doc->itemtype     = $itemtype;
  40          $doc->contextid    = $context_id;
  41  
  42          $doc->title        = $post['subject'];
  43          
  44          $user = get_record('user', 'id', $post['userid']);
  45          $doc->author       = fullname($user);
  46          $doc->contents     = $post['message'];
  47          $doc->date         = $post['created'];
  48          $doc->url          = forum_make_link($post['discussion'], $post['id']);
  49          
  50          // module specific information
  51          $data->forum      = $forum_id;
  52          $data->discussion = $post['discussion'];
  53          
  54          parent::__construct($doc, $data, $course_id, $post['groupid'], $post['userid'], PATH_FOR_SEARCH_TYPE_FORUM);
  55      } 
  56  }
  57  
  58  /**
  59  * constructs a valid link to a chat content
  60  * @param discussion_id the discussion
  61  * @param post_id the id of a single post
  62  * @return a well formed link to forum message display
  63  */
  64  function forum_make_link($discussion_id, $post_id) {
  65      global $CFG;
  66      
  67      return $CFG->wwwroot.'/mod/forum/discuss.php?d='.$discussion_id.'#'.$post_id;
  68  }
  69  
  70  /**
  71  * search standard API
  72  *
  73  */
  74  function forum_iterator() {
  75      $forums = get_records('forum');
  76      return $forums;
  77  }
  78  
  79  /**
  80  * search standard API
  81  * @param forum a forum instance
  82  * @return an array of searchable documents
  83  */
  84  function forum_get_content_for_index(&$forum) {
  85  
  86      $documents = array();
  87      if (!$forum) return $documents;
  88  
  89      $posts = forum_get_discussions_fast($forum->id);
  90      if (!$posts) return $documents;
  91  
  92      $coursemodule = get_field('modules', 'id', 'name', 'forum');
  93      $cm = get_record('course_modules', 'course', $forum->course, 'module', $coursemodule, 'instance', $forum->id);
  94      $context = get_context_instance(CONTEXT_MODULE, $cm->id);
  95  
  96      foreach($posts as $aPost) {
  97          $aPost->itemtype = 'head';
  98          if ($aPost) {
  99              if (strlen($aPost->message) > 0) {
 100                  $documents[] = new ForumSearchDocument(get_object_vars($aPost), $forum->id, $forum->course, 'head', $context->id);
 101              } 
 102              if ($children = forum_get_child_posts_fast($aPost->id, $forum->id)) {
 103                  foreach($children as $aChild) {
 104                      $aChild->itemtype = 'post';
 105                      if (strlen($aChild->message) > 0) {
 106                          $documents[] = new ForumSearchDocument(get_object_vars($aChild), $forum->id, $forum->course, 'post', $context->id);
 107                      } 
 108                  } 
 109              } 
 110          } 
 111      } 
 112      return $documents;
 113  }
 114  
 115  /**
 116  * returns a single forum search document based on a forum entry id
 117  * @param id an id for a single information stub
 118  * @param itemtype the type of information
 119  */
 120  function forum_single_document($id, $itemtype) {
 121  
 122      // both known item types are posts so get them the same way
 123      $post = get_record('forum_posts', 'id', $id);
 124      $discussion = get_record('forum_discussions', 'id', $post->discussion);
 125      $coursemodule = get_field('modules', 'id', 'name', 'forum');
 126      $cm = get_record('course_modules', 'course', $discussion->course, 'module', $coursemodule, 'instance', $discussion->forum);
 127      if ($cm){
 128          $context = get_context_instance(CONTEXT_MODULE, $cm->id);
 129          $post->groupid = $discussion->groupid;
 130          return new ForumSearchDocument(get_object_vars($post), $discussion->forum, $discussion->course, $itemtype, $context->id);
 131      }
 132      return null;
 133  }
 134  
 135  /**
 136  * dummy delete function that aggregates id with itemtype.
 137  * this was here for a reason, but I can't remember it at the moment.
 138  *
 139  */
 140  function forum_delete($info, $itemtype) {
 141      $object->id = $info;
 142      $object->itemtype = $itemtype;
 143      return $object;
 144  }
 145  
 146  /**
 147  * returns the var names needed to build a sql query for addition/deletions
 148  *
 149  */
 150  function forum_db_names() {
 151      //[primary id], [table name], [time created field name], [time modified field name]
 152      return array(
 153          array('id', 'forum_posts', 'created', 'modified', 'head', 'parent = 0'),
 154          array('id', 'forum_posts', 'created', 'modified', 'post', 'parent != 0')
 155      );
 156  }
 157  
 158  /**
 159  * reworked faster version from /mod/forum/lib.php
 160  * @param forum_id a forum identifier
 161  * @uses CFG, USER
 162  * @return an array of posts
 163  */
 164  function forum_get_discussions_fast($forum_id) {
 165      global $CFG, $USER;
 166      
 167      $timelimit='';
 168      if (!empty($CFG->forum_enabletimedposts)) {
 169          if (!((isadmin() and !empty($CFG->admineditalways)) || isteacher(get_field('forum', 'course', 'id', $forum_id)))) {
 170              $now = time();
 171              $timelimit = " AND ((d.timestart = 0 OR d.timestart <= '$now') AND (d.timeend = 0 OR d.timeend > '$now')";
 172              if (!empty($USER->id)) {
 173                  $timelimit .= " OR d.userid = '$USER->id'";
 174              }
 175              $timelimit .= ')';
 176          }
 177      }
 178      
 179      $query = "
 180          SELECT 
 181              p.id, 
 182              p.subject, 
 183              p.discussion, 
 184              p.message,
 185              p.created,
 186              d.groupid,
 187              p.userid, 
 188              u.firstname, 
 189              u.lastname
 190          FROM 
 191              {$CFG->prefix}forum_discussions d
 192          JOIN 
 193              {$CFG->prefix}forum_posts p 
 194          ON 
 195              p.discussion = d.id
 196          JOIN 
 197              {$CFG->prefix}user u 
 198          ON 
 199              p.userid = u.id
 200          WHERE 
 201              d.forum = '{$forum_id}' AND 
 202              p.parent = 0
 203              $timelimit
 204          ORDER BY 
 205              d.timemodified DESC
 206      ";
 207      return get_records_sql($query);
 208  }
 209  
 210  /**
 211  * reworked faster version from /mod/forum/lib.php
 212  * @param parent the id of the first post within the discussion
 213  * @param forum_id the forum identifier
 214  * @uses CFG
 215  * @return an array of posts
 216  */
 217  function forum_get_child_posts_fast($parent, $forum_id) {
 218      global $CFG;
 219      
 220      $query = "
 221          SELECT 
 222              p.id, 
 223              p.subject, 
 224              p.discussion, 
 225              p.message, 
 226              p.created, 
 227              {$forum_id} AS forum,
 228              p.userid,
 229              d.groupid,
 230              u.firstname, 
 231              u.lastname
 232          FROM 
 233              {$CFG->prefix}forum_discussions d
 234          JOIN 
 235              {$CFG->prefix}forum_posts p 
 236          ON 
 237              p.discussion = d.id
 238          JOIN 
 239              {$CFG->prefix}user u 
 240          ON 
 241              p.userid = u.id
 242          WHERE 
 243              p.parent = '{$parent}'
 244          ORDER BY 
 245              p.created ASC
 246      ";
 247      return get_records_sql($query);
 248  }
 249  
 250  /**
 251  * this function handles the access policy to contents indexed as searchable documents. If this 
 252  * function does not exist, the search engine assumes access is allowed.
 253  * When this point is reached, we already know that : 
 254  * - user is legitimate in the surrounding context
 255  * - user may be guest and guest access is allowed to the module
 256  * - the function may perform local checks within the module information logic
 257  * @param path the access path to the module script code
 258  * @param itemtype the information subclassing (usefull for complex modules, defaults to 'standard')
 259  * @param this_id the item id within the information class denoted by itemtype. In forums, this id 
 260  * points out the individual post.
 261  * @param user the user record denoting the user who searches
 262  * @param group_id the current group used by the user when searching
 263  * @uses CFG, USER
 264  * @return true if access is allowed, false elsewhere
 265  */
 266  function forum_check_text_access($path, $itemtype, $this_id, $user, $group_id, $context_id){
 267      global $CFG, $USER;
 268      
 269      include_once("{$CFG->dirroot}/{$path}/lib.php");
 270  
 271      // get the forum post and all related stuff
 272      $post = get_record('forum_posts', 'id', $this_id);
 273      $discussion = get_record('forum_discussions', 'id', $post->discussion);
 274      $context = get_record('context', 'id', $context_id);
 275      $cm = get_record('course_modules', 'id', $context->instanceid);
 276      // $cm = get_coursemodule_from_instance('forum', $discussion->forum, $discussion->course);
 277      // $context = get_context_instance(CONTEXT_MODULE, $cm->id);
 278      if (!$cm->visible and !has_capability('moodle/course:viewhiddenactivities', $context)){
 279          if (!empty($CFG->search_access_debug)) echo "search reject : hidden forum resource ";
 280          return false;
 281      }
 282      
 283      // approval check : entries should be approved for being viewed, or belongs to the user 
 284      if (($post->userid != $USER->id) && !$post->mailed && !has_capability('mod/forum:viewhiddentimeposts', $context)){
 285          if (!empty($CFG->search_access_debug)) echo "search reject : time hidden forum item";
 286          return false;
 287      }
 288  
 289      // group check : entries should be in accessible groups
 290      $current_group = get_current_group($discussion->course);
 291      $course = get_record('course', 'id', $discussion->course);
 292      if ($group_id >= 0 && (groupmode($course, $cm)  == SEPARATEGROUPS) && ($group_id != $current_group) && !has_capability('mod/forum:viewdiscussionsfromallgroups', $context)){
 293          if (!empty($CFG->search_access_debug)) echo "search reject : separated grouped forum item";
 294          return false;
 295      }
 296      
 297      return true;
 298  }
 299  
 300  /**
 301  * post processes the url for cleaner output.
 302  * @param string $title
 303  */
 304  function forum_link_post_processing($title){
 305      return mb_convert_encoding($title, 'UTF-8', 'auto');
 306  }
 307  
 308  ?>