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;
  36
  37         // Trivial-cache - keyed on $cachedcontextid
  38         static $cachedcontextid;
  39         static $contentlist;
  40
  41         static $nothingtodo;
  42
  43         // Try to get current course.
  44         $coursectx = $this->context->get_course_context(false);
  45         if (!$coursectx) {
  46             $courseid = 0;
  47         } else {
  48             $courseid = $coursectx->instanceid;
  49         }
  50
  51         // Initialise/invalidate our trivial cache if dealing with a different context
  52         if (!isset($cachedcontextid) || $cachedcontextid !== $this->context->id) {
  53             $cachedcontextid = $this->context->id;
  54             $contentlist = array();
  55             $nothingtodo = false;
  56         }
  57
  58         if ($nothingtodo === true) {
  59             return $text;
  60         }
  61
  62         // Create a list of all the resources to search for. It may be cached already.
  63         if (empty($contentlist)) {
  64             $coursestosearch = $courseid ? array($courseid) : array(); // Add courseid if found
  65             if (get_site()->id != $courseid) { // Add siteid if was not courseid
  66                 $coursestosearch[] = get_site()->id;
  67             }
  68             // We look for text field contents only if have autolink enabled (param1)
  69             list ($coursesql, $params) = $DB->get_in_or_equal($coursestosearch);
  70             $sql = 'SELECT dc.id AS contentid, dr.id AS recordid, dc.content AS content, d.id AS dataid
  71                       FROM {data} d
  72                       JOIN {data_fields} df ON df.dataid = d.id
  73                       JOIN {data_records} dr ON dr.dataid = d.id
  74                       JOIN {data_content} dc ON dc.fieldid = df.id AND dc.recordid = dr.id
  75                      WHERE d.course ' . $coursesql . '
  76                        AND df.type = \'text\'
  77                        AND ' . $DB->sql_compare_text('df.param1', 1) . " = '1'";
  78
  79             if (!$contents = $DB->get_records_sql($sql, $params)) {
  80                 $nothingtodo = true;
  81                 return $text;
  82             }
  83
  84             foreach ($contents as $key => $content) {
  85                 // Trim empty or unlinkable concepts
  86                 $currentcontent = trim(strip_tags($content->content));
  87                 if (empty($currentcontent)) {
  88                     unset($contents[$key]);
  89                     continue;
  90                 } else {
  91                     $contents[$key]->content = $currentcontent;
  92                 }
  93
  94                 // Rule out any small integers.  See bug 1446
  95                 $currentint = intval($currentcontent);
  96                 if ($currentint && (strval($currentint) == $currentcontent) && $currentint < 1000) {
  97                     unset($contents[$key]);
  98                 }
  99             }
 100
 101             if (empty($contents)) {
 102                 $nothingtodo = true;
 103                 return $text;
 104             }
 105
 106             usort($contents, 'filter_data::sort_entries_by_length');
 107
 108             foreach ($contents as $content) {
 109                 $href_tag_begin = '<a class="data autolink dataid'.$content->dataid.'" title="'.$content->content.'" '.
 110                                   'href="'.$CFG->wwwroot.'/mod/data/view.php?d='.$content->dataid.
 111                                   '&amp;rid='.$content->recordid.'">';
 112                 $contentlist[] = new filterobject($content->content, $href_tag_begin, '</a>', false, true);
 113             }
 114
 115             $contentlist = filter_remove_duplicates($contentlist); // Clean dupes
 116         }
 117         return filter_phrases($text, $contentlist);  // Look for all these links in the text
 118     }
 119
 120     private static function sort_entries_by_length($content0, $content1) {
 121         $len0 = strlen($content0->content);
 122         $len1 = strlen($content1->content);
 123
 124         if ($len0 < $len1) {
 125             return 1;
 126         } else if ($len0 > $len1) {
 127             return -1;
 128         } else {
 129             return 0;
 130         }
 131     }
 132 }