filter/data/filter.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * This filter provides automatic linking to database activity entries
  19  * when found inside every Moodle text.
  20  *
  21  * @package    filter
  22  * @subpackage data
  23  * @copyright  2006 Vy-Shane Sin Fat
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 /**
  30  * Database activity filtering
  31  */
  32 class filter_data extends moodle_text_filter {
  33
  34     public function filter($text, array $options = array()) {
  35         global $CFG, $DB, $USER;
  36
  37         // Trivial-cache - keyed on $cachedcourseid + $cacheduserid.
  38         static $cachedcourseid = null;
  39         static $cacheduserid = null;
  40         static $coursecontentlist = array();
  41         static $sitecontentlist = array();
  42
  43         static $nothingtodo;
  44
  45         // Try to get current course.
  46         $coursectx = $this->context->get_course_context(false);
  47         if (!$coursectx) {
  48             // We could be in a course category so no entries for courseid == 0 will be found.
  49             $courseid = 0;
  50         } else {
  51             $courseid = $coursectx->instanceid;
  52         }
  53
  54         if ($cacheduserid !== $USER->id) {
  55             // Invalidate all caches if the user changed.
  56             $coursecontentlist = array();
  57             $sitecontentlist = array();
  58             $cacheduserid = $USER->id;
  59             $cachedcourseid = $courseid;
  60             $nothingtodo = false;
  61         } else if ($courseid != get_site()->id && $courseid != 0 && $cachedcourseid != $courseid) {
  62             // Invalidate course-level caches if the course id changed.
  63             $coursecontentlist = array();
  64             $cachedcourseid = $courseid;
  65             $nothingtodo = false;
  66         }
  67
  68         if ($nothingtodo === true) {
  69             return $text;
  70         }
  71
  72         // If courseid == 0 only site entries will be returned.
  73         if ($courseid == get_site()->id || $courseid == 0) {
  74             $contentlist = & $sitecontentlist;
  75         } else {
  76             $contentlist = & $coursecontentlist;
  77         }
  78
  79         // Create a list of all the resources to search for. It may be cached already.
  80         if (empty($contentlist)) {
  81             $coursestosearch = $courseid ? array($courseid) : array(); // Add courseid if found
  82             if (get_site()->id != $courseid) { // Add siteid if was not courseid
  83                 $coursestosearch[] = get_site()->id;
  84             }
  85             // We look for text field contents only if have autolink enabled (param1)
  86             list ($coursesql, $params) = $DB->get_in_or_equal($coursestosearch);
  87             $sql = 'SELECT dc.id AS contentid, dr.id AS recordid, dc.content AS content, d.id AS dataid
  88                       FROM {data} d
  89                       JOIN {data_fields} df ON df.dataid = d.id
  90                       JOIN {data_records} dr ON dr.dataid = d.id
  91                       JOIN {data_content} dc ON dc.fieldid = df.id AND dc.recordid = dr.id
  92                      WHERE d.course ' . $coursesql . '
  93                        AND df.type = \'text\'
  94                        AND ' . $DB->sql_compare_text('df.param1', 1) . " = '1'";
  95
  96             if (!$contents = $DB->get_records_sql($sql, $params)) {
  97                 $nothingtodo = true;
  98                 return $text;
  99             }
 100
 101             foreach ($contents as $key => $content) {
 102                 // Trim empty or unlinkable concepts
 103                 $currentcontent = trim(strip_tags($content->content));
 104                 if (empty($currentcontent)) {
 105                     unset($contents[$key]);
 106                     continue;
 107                 } else {
 108                     $contents[$key]->content = $currentcontent;
 109                 }
 110
 111                 // Rule out any small integers.  See bug 1446
 112                 $currentint = intval($currentcontent);
 113                 if ($currentint && (strval($currentint) == $currentcontent) && $currentint < 1000) {
 114                     unset($contents[$key]);
 115                 }
 116             }
 117
 118             if (empty($contents)) {
 119                 $nothingtodo = true;
 120                 return $text;
 121             }
 122
 123             usort($contents, 'filter_data::sort_entries_by_length');
 124
 125             foreach ($contents as $content) {
 126                 $href_tag_begin = '<a class="data autolink dataid'.$content->dataid.'" title="'.$content->content.'" '.
 127                                   'href="'.$CFG->wwwroot.'/mod/data/view.php?d='.$content->dataid.
 128                                   '&amp;rid='.$content->recordid.'">';
 129                 $contentlist[] = new filterobject($content->content, $href_tag_begin, '</a>', false, true);
 130             }
 131
 132             $contentlist = filter_remove_duplicates($contentlist); // Clean dupes
 133         }
 134         return filter_phrases($text, $contentlist);  // Look for all these links in the text
 135     }
 136
 137     private static function sort_entries_by_length($content0, $content1) {
 138         $len0 = strlen($content0->content);
 139         $len1 = strlen($content1->content);
 140
 141         if ($len0 < $len1) {
 142             return 1;
 143         } else if ($len0 > $len1) {
 144             return -1;
 145         } else {
 146             return 0;
 147         }
 148     }
 149 }