filter.module 43 KB
Newer Older
1
2
3
<?php
// $Id$

Dries's avatar
   
Dries committed
4
5
6
7
8
/**
 * @file
 * Framework for handling filtering of content.
 */

9
10
11
// This is a special format ID which means "use the default format". This value
// can be passed to the filter APIs as a format ID: this is equivalent to not
// passing an explicit format at all.
12
13
define('FILTER_FORMAT_DEFAULT', 0);

14
15
16
17
18
19
define('FILTER_HTML_STRIP', 1);
define('FILTER_HTML_ESCAPE', 2);

define('FILTER_STYLE_ALLOW', 0);
define('FILTER_STYLE_STRIP', 1);

Dries's avatar
Dries committed
20
21
22
23
/**
 * Implementation of hook_help().
 */
function filter_help($section) {
24
  switch ($section) {
Dries's avatar
   
Dries committed
25
    case 'admin/modules#description':
26
      return t('Handles the filtering of content in preparation for display.');
27

Dries's avatar
   
Dries committed
28
    case 'admin/filters':
29
      return t('
Dries's avatar
   
Dries committed
30
<p><em>Input formats</em> define a way of processing user-supplied text in Drupal. Every input format has its own settings of which <em>filters</em> to apply. Possible filters include stripping out malicious HTML and making URLs clickable.</p>
31
32
33
<p>Users can choose between the available input formats when submitting content.</p>
<p>Below you can configure which input formats are available to which roles, as well as choose a default input format (used for imported content, for example).</p>');

34
    case 'admin/filters/'. arg(2):
35
      return t('
Dries's avatar
   
Dries committed
36
<p>Every <em>filter</em> performs one particular change on the user input, for example stripping out malicious HTML or making URLs clickable. Choose which filters you want to apply to text in this input format.</p>
37
<p>If you notice some filters are causing conflicts in the output, you can <a href="%rearrange">rearrange them</a>.</p>', array('%rearrange' => url('admin/filters/'. arg(2) .'/order')));
38

39
    case 'admin/filters/'. arg(2) .'/configure':
40
      return t('
41
<p>If you cannot find the settings for a certain filter, make sure you\'ve enabled it on the <a href="%url">view tab</a> first.</p>', array('%url' => url('admin/filters/'. arg(2))));
42

43
    case 'admin/filters/'. arg(2) .'/order':
44
      return t('
Dries's avatar
   
Dries committed
45
<p>Because of the flexible filtering system, you might encounter a situation where one filter prevents another from doing its job. For example: a word in an URL gets converted into a glossary term, before the URL can be converted in a clickable link. When this happens, you will need to rearrange the order in which filters get executed.</p>
46
47
48
49
50
<p>Filters are executed from top-to-bottom. You can use the weight column to rearrange them: heavier filters \'sink\' to the bottom.</p>');
  }
}

/**
51
 * Implementation of hook_filter_tips().
52
 */
53
function filter_filter_tips($delta, $format, $long = false) {
54
  global $base_url;
55
56
57
58
59
  switch ($delta) {
    case 0:
      switch (variable_get("filter_html_$format", FILTER_HTML_STRIP)) {

        case FILTER_HTML_STRIP:
Dries's avatar
   
Dries committed
60
          if ($allowed_html = variable_get("allowed_html_$format", '<a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>')) {
61
62
            switch ($long) {
              case 0:
63
                return t('Allowed HTML tags') .': '. check_plain($allowed_html);
64
              case 1:
65
                $output = '<p>'. t('Allowed HTML tags') .': '. check_plain($allowed_html) .'</p>';
66
67
68
69
                if (!variable_get("filter_html_help_$format", 1)) {
                  return $output;
                }

70
71
                $output .= t('
<p>This site allows HTML content. While learning all of HTML may feel intimidating, learning how to use a very small number of the most basic HTML "tags" is very easy. This table provides examples for each tag that is enabled on this site.</p>
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
<p>For more information see W3C\'s <a href="http://www.w3.org/TR/html/">HTML Specifications</a> or use your favorite search engine to find other sites that explain HTML.</p>');
                $tips = array(
                  'a' => array( t('Anchors are used to make links to other pages.'), '<a href="'. $base_url .'">'. variable_get('site_name', 'drupal') .'</a>'),
                  'br' => array( t('By default line break tags are automatically added, so use this tag to add additional ones. Use of this tag is different because it is not used with an open/close pair like all the others. Use the extra " /" inside the tag to maintain XHTML 1.0 compatibility'), t('Text with <br />line break')),
                  'p' => array( t('By default paragraph tags are automatically added, so use this tag to add additional ones.'), '<p>'. t('Paragraph one.') .'</p> <p>'. t('Paragraph two.') .'</p>'),
                  'strong' => array( t('Strong'), '<strong>'. t('Strong'). '</strong>'),
                  'em' => array( t('Emphasized'), '<em>'. t('Emphasized') .'</em>'),
                  'cite' => array( t('Cited'), '<cite>'. t('Cited') .'</cite>'),
                  'code' => array( t('Coded text used to show programming source code'), '<code>'. t('Coded') .'</code>'),
                  'b' => array( t('Bolded'), '<b>'. t('Bolded') .'</b>'),
                  'u' => array( t('Underlined'), '<u>'. t('Underlined') .'</u>'),
                  'i' => array( t('Italicized'), '<i>'. t('Italicized') .'</i>'),
                  'sup' => array( t('Superscripted'), t('<sup>Super</sup>scripted')),
                  'sub' => array( t('Subscripted'), t('<sub>Sub</sub>scripted')),
                  'pre' => array( t('Preformatted'), '<pre>'. t('Preformatted') .'</pre>'),
                  'blockquote' => array( t('Block quoted'), '<blockquote>'. t('Block quoted') .'</blockquote>'),
                  'q' => array( t('Quoted inline'), '<q>'. t('Quoted inline') .'</q>'),
                  // Assumes and describes tr, td, th.
                  'table' => array( t('Table'), '<table> <tr><th>'. t('Table header') .'</th></tr> <tr><td>'. t('Table cell') .'</td></tr> </table>'),
                  'tr' => NULL, 'td' => NULL, 'th' => NULL,
                  'del' => array( t('Deleted'), '<del>'. t('Deleted') .'</del>'),
                  'ins' => array( t('Inserted'), '<ins>'. t('Inserted') .'</ins>'),
                   // Assumes and describes li.
                  'ol' => array( t('Ordered list - use the &lt;li&gt; to begin each list item'), '<ol> <li>'. t('First item') .'</li> <li>'. t('Second item') .'</li> </ol>'),
                  'ul' => array( t('Unordered list - use the &lt;li&gt; to begin each list item'), '<ul> <li>'. t('First item') .'</li> <li>'. t('Second item') .'</li> </ul>'),
                  'li' => NULL,
                  // Assumes and describes dt and dd.
                  'dl' => array( t('Definition lists are similar to other HTML lists. &lt;dl&gt; begins the definition list, &lt;dt&gt; begins the definition term and &lt;dd&gt; begins the definition description.'), '<dl> <dt>'. t('First term') .'</dt> <dd>'. t('First definition') .'</dd> <dt>'. t('Second term') .'</dt> <dd>'. t('Second definition') .'</dd> </dl>'),
                  'dt' => NULL, 'dd' => NULL,
                  'h1' => array( t('Header'), '<h1>'. t('Title') .'</h1>'),
                  'h2' => array( t('Header'), '<h2>'. t('Subtitle') .'</h2>'),
                  'h3' => array( t('Header'), '<h3>'. t('Subtitle three') .'</h3>'),
                  'h4' => array( t('Header'), '<h4>'. t('Subtitle four') .'</h4>'),
                  'h5' => array( t('Header'), '<h5>'. t('Subtitle five') .'</h5>'),
                  'h6' => array( t('Header'), '<h6>'. t('Subtitle six') .'</h6>')
                );
                $header = array(t('Tag Description'), t('You Type'), t('You Get'));
                preg_match_all('/<([a-z0-9]+)[^a-z0-9]/i', $allowed_html, $out);
                foreach ($out[1] as $tag) {
                  if (array_key_exists($tag, $tips)) {
                    if ($tips[$tag]) {
                      $rows[] = array(
                        array('data' => $tips[$tag][0], 'class' => 'description'),
115
                        array('data' => '<code>'. check_plain($tips[$tag][1]) .'</code>', 'class' => 'type'),
116
117
118
119
120
121
                        array('data' => $tips[$tag][1], 'class' => 'get')
                      );
                    }
                  }
                  else {
                    $rows[] = array(
122
                      array('data' => t('No help provided for tag %tag.', array('%tag' => check_plain($tag))), 'class' => 'description', 'colspan' => 3),
123
124
125
126
127
                    );
                  }
                }
                $output .= theme('table', $header, $rows);

128
129
                $output .= t('
<p>Most unusual characters can be directly entered without any problems.</p>
130
131
132
133
134
135
136
137
138
139
140
141
<p>If you do encounter problems, try using HTML character entities. A common example looks like &amp;amp; for an ampersand &amp; character. For a full list of entities see HTML\'s <a href="http://www.w3.org/TR/html4/sgml/entities.html">entities</a> page. Some of the available characters include:</p>');
                $entities = array(
                  array( t('Ampersand'), '&amp;'),
                  array( t('Greater than'), '&gt;'),
                  array( t('Less than'), '&lt;'),
                  array( t('Quotation mark'), '&quot;'),
                );
                $header = array(t('Character Description'), t('You Type'), t('You Get'));
                unset($rows);
                foreach ($entities as $entity) {
                  $rows[] = array(
                    array('data' => $entity[0], 'class' => 'description'),
142
                    array('data' => '<code>'. check_plain($entity[1]) .'</code>', 'class' => 'type'),
143
144
145
146
147
148
                    array('data' => $entity[1], 'class' => 'get')
                  );
                }
                $output .= theme('table', $header, $rows);
                return $output;
            }
149
150
          }
          else {
Dries's avatar
Dries committed
151
            return t('No HTML tags allowed');
Dries's avatar
   
Dries committed
152
          }
153
154

        case FILTER_STYLE_STRIP:
Dries's avatar
Dries committed
155
          return t('No HTML tags allowed');
Dries's avatar
   
Dries committed
156
157
      }
      break;
158
159

    case 1:
Dries's avatar
   
Dries committed
160
      switch ($long) {
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
        case 0:
          return t('You may post PHP code. You should include &lt;?php ?&gt; tags.');
        case 1:
          return t('
<h4>Using custom PHP code</h4>
<p>If you know how to script in PHP, Drupal gives you the power to embed any script you like. It will be executed when the page is viewed and dynamically embedded into the page. This gives you amazing flexibility and power, but of course with that comes danger and insecurity if you don\'t write good code. If you are not familiar with PHP, SQL or with the site engine, avoid experimenting with PHP because you can corrupt your database or render your site insecure or even unusable! If you don\'t plan to do fancy stuff with your content then you\'re probably better off with straight HTML.</p>
<p>Remember that the code within each PHP item must be valid PHP code - including things like correctly terminating statements with a semicolon. It is highly recommended that you develop your code separately using a simple test script on top of a test database before migrating to your production environment.</p>
<p>Notes:</p><ul><li>You can use global variables, such as configuration parameters, within the scope of your PHP code but remember that global variables which have been given values in your code will retain these values in the engine afterwards.</li><li>register_globals is now set to <strong>off</strong> by default. If you need form information you need to get it from the "superglobals" $_POST, $_GET, etc.</li><li>You can either use the <code>print</code> or <code>return</code> statement to output the actual content for your item.</li></ul>
<p>A basic example:</p>
<blockquote><p>You want to have a box with the title "Welcome" that you use to greet your visitors. The content for this box could be created by going:</p>
<pre>
  print t("Welcome visitor, ... welcome message goes here ...");
</pre>
<p>If we are however dealing with a registered user, we can customize the message by using:</p>
<pre>
  global $user;
  if ($user->uid) {
    print t("Welcome $user->name, ... welcome message goes here ...");
  }
  else {
    print t("Welcome visitor, ... welcome message goes here ...");
  }
</pre></blockquote>
<p>For more in-depth examples, we recommend that you check the existing Drupal code and use it as a starting point, especially for sidebar boxes.</p>');
      }

187
    case 2:
188
189
190
191
192
193
      switch ($long) {
        case 0:
          return t('Lines and paragraphs break automatically.');
        case 1:
          return t('Lines and paragraphs are automatically recognized. The &lt;br /&gt; line break, &lt;p&gt; paragraph and &lt;/p&gt; close paragraph tags are inserted automatically. If paragraphs are not recognized simply add a couple blank lines.');
      }
194
195
196
  }
}

197

Dries's avatar
   
Dries committed
198
/**
Dries's avatar
   
Dries committed
199
 * Implementation of hook_menu().
Dries's avatar
   
Dries committed
200
 */
Dries's avatar
   
Dries committed
201
function filter_menu($may_cache) {
Dries's avatar
   
Dries committed
202
  $items = array();
203

Dries's avatar
   
Dries committed
204
205
206
  if ($may_cache) {
    $items[] = array('path' => 'admin/filters', 'title' => t('input formats'),
      'callback' => 'filter_admin_overview',
207
      'access' => user_access('administer filters'));
208
209
210
211
212
213
214
215
216
    $items[] = array('path' => 'admin/filters/list', 'title' => t('list'),
      'callback' => 'filter_admin_overview',
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'access' => user_access('administer filters'));
    $items[] = array('path' => 'admin/filters/add', 'title' => t('add input format'),
      'callback' => 'filter_admin_add',
      'type' => MENU_LOCAL_TASK,
      'weight' => 1,
      'access' => user_access('administer filters'));
Dries's avatar
   
Dries committed
217
218
219
    $items[] = array('path' => 'admin/filters/delete', 'title' => t('delete input format'),
      'callback' => 'filter_admin_delete',
      'type' => MENU_CALLBACK,
220
      'access' => user_access('administer filters'));
Dries's avatar
   
Dries committed
221
222
223
224
225
226
227
228
229
230
    $items[] = array('path' => 'filter/tips', 'title' => t('compose tips'),
      'callback' => 'filter_tips_long', 'access' => TRUE,
      'type' => MENU_SUGGESTED_ITEM);
  }
  else {
    if (arg(0) == 'admin' && arg(1) == 'filters' && is_numeric(arg(2))) {
      $formats = filter_formats();

      if (isset($formats[arg(2)])) {
        $items[] = array('path' => 'admin/filters/'. arg(2), 'title' => t("'%format' input format", array('%format' => $formats[arg(2)]->name)),
231
232
233
234
235
236
237
238
239
240
          'callback' => 'filter_admin_format',
          'callback arguments' => array('format' => $formats[arg(2)]),
          'type' => MENU_CALLBACK,
          'access' => user_access('administer filters'));
        $items[] = array('path' => 'admin/filters/'. arg(2) .'/list', 'title' => t('view'),
          'callback' => 'filter_admin_format',
          'callback arguments' => array('format' => $formats[arg(2)]),
          'type' => MENU_DEFAULT_LOCAL_TASK,
          'weight' => 0,
          'access' => user_access('administer filters'));
Dries's avatar
   
Dries committed
241
        $items[] = array('path' => 'admin/filters/'. arg(2) .'/configure', 'title' => t('configure'),
242
243
244
245
          'callback' => 'filter_admin_configure',
          'type' => MENU_LOCAL_TASK,
          'weight' => 1,
          'access' => user_access('administer filters'));
Dries's avatar
   
Dries committed
246
        $items[] = array('path' => 'admin/filters/'. arg(2) .'/order', 'title' => t('rearrange'),
247
248
249
250
          'callback' => 'filter_admin_order',
          'type' => MENU_LOCAL_TASK,
          'weight' => 2,
          'access' => user_access('administer filters'));
Dries's avatar
   
Dries committed
251
      }
252
253
254
    }
  }

Dries's avatar
   
Dries committed
255
  return $items;
256
257
}

Dries's avatar
Dries committed
258
/**
259
 * Implementation of hook_perm().
Dries's avatar
Dries committed
260
 */
261
262
263
264
265
function filter_perm() {
  return array('administer filters');
}

/**
266
 * Displays a list of all input formats and which one is the default
267
268
 */
function filter_admin_overview() {
269
270
271
272
273
274
275

  $edit = isset($_POST['edit']) ? $_POST['edit'] : '';

  // Process form submission to set the default format
  if (is_numeric($edit['default'])) {
    drupal_set_message(t('Default format updated.'));
    variable_set('filter_default_format', $edit['default']);
276
277
  }

278
  // Overview of all formats.
279
280
281
282
283
  $formats = filter_formats();
  $error = false;

  $rows = array();
  foreach ($formats as $id => $format) {
284
285
286
    $roles = array();
    foreach (user_roles() as $rid => $name) {
      //prepare a roles array with roles that may access the filter
287
      if (strstr($format->roles, ",$rid,")) {
288
289
290
        $roles[] = $name;
      }
    }
291
292
    $row = array();
    $default = ($id == variable_get('filter_default_format', 1));
293
    $options[$id] = '';
294
295
296
297
    $form[$format->name]['id'] = array('#type' => 'markup', '#value' => $id);
    $form[$format->name]['roles'] = array('#type' => 'markup', '#value' => $roles ? implode(', ',$roles) : t('No roles may use this format'));
    $form[$format->name]['configure'] = array('#type' => 'markup', '#value' => l(t('configure'), 'admin/filters/'. $id));
    $form[$format->name]['delete'] = array('#type' => 'markup', '#value' => $default ? '' : l('delete', 'admin/filters/delete/'. $id));
298
  }
299
300
  $form['default'] = array('#type' => 'radios', '#options' => $options, '#default_value' => variable_get('filter_default_format', 1));
  $form['submit'] = array('#type' => 'submit', '#value' => t('Set default format'));
301
302
  return drupal_get_form('filter_admin_overview', $form);
}
303

304
305
306
307
function theme_filter_admin_overview($form) {
  foreach ($form as $name => $element) {
    if (isset($element['roles']) && is_array($element['roles'])) {
      $rows[] = array(
308
        form_render($form['default'][$element['id']['#value']]),
309
310
311
312
313
314
315
316
317
318
319
        $name,
        form_render($element['roles']),
        form_render($element['configure']),
        form_render($element['delete'])
      );
      unset($form[$name]);
    }
  }
  $header = array(t('Default'), t('Name'), t('Roles'), array('data' => t('Operations'), 'colspan' => 2));
  $output = theme('table', $header, $rows);
  $output .= form_render($form);
320

Dries's avatar
   
Dries committed
321
  return $output;
322
323
324
}

/**
325
 * Add a new input format.
326
327
 */
function filter_admin_add() {
328
329
  if ($_POST['op']) {
    $edit = $_POST['edit'];
330

331
    filter_admin_filters_save($format->format, $edit);
332
333
  }

334
  $output = filter_admin_format_form($format);
335
  return $output;
336
337
338
}

/**
339
 * Menu callback; confirm deletion of a format.
340
341
342
 */
function filter_admin_delete() {
  $edit = $_POST['edit'];
343
  if ($edit['confirm']) {
344
345
346
347
348
    if ($edit['format'] != variable_get('filter_default_format', 1)) {
      db_query("DELETE FROM {filter_formats} WHERE format = %d", $edit['format']);
      db_query("DELETE FROM {filters} WHERE format = %d", $edit['format']);

      $default = variable_get('filter_default_format', 1);
349
      db_query("UPDATE {node_revisions} SET format = %d WHERE format = %d", $default, $edit['format']);
350
351
352
353
354
      db_query("UPDATE {comments} SET format = %d WHERE format = %d", $default, $edit['format']);
      db_query("UPDATE {boxes} SET format = %d WHERE format = %d", $default, $edit['format']);

      cache_clear_all('filter:'. $edit['format'], true);

355
      drupal_set_message(t('Deleted input format %format.', array('%format' => theme('placeholder', $edit['name']))));
356
357
358
359
360
361
362
    }
    drupal_goto('admin/filters');
  }

  $format = arg(3);
  $format = db_fetch_object(db_query('SELECT * FROM {filter_formats} WHERE format = %d', $format));

363
364
  $form['format'] = array('#type' => 'hidden', '#value' => $format->format);
  $form['name'] = array('#type' => 'hidden', '#value' => $format->name);
365
366
367
368

  return confirm_form('filter_admin_delete', $form, t('Are you sure you want to delete the input format %format?', array('%format' => theme('placeholder', $format->name))), 'admin/filters', t('If you have any content left in this input format, it will be switched to the default input format. This action cannot be undone.'), t('Delete'), t('Cancel'));


369
370
371
}

/**
372
 * Menu callback; configure the filters for a format.
373
 */
374
function filter_admin_format($format) {
375
  if ($_POST['op']) {
376
377
    $edit = $_POST['edit'];
    filter_admin_filters_save($format->format, $edit);
378
379
  }

380
  $output = filter_admin_format_form($format);
381

382
  // Composition tips (guidelines)
383
  $tips = _filter_tips($format->format, false);
384
  $extra = l(t('More information about formatting options'), 'filter/tips');
Dries's avatar
   
Dries committed
385
  $tiplist = theme('filter_tips', $tips, false, $extra);
386
387
388
389
390
391
392
  if (!$tiplist) {
    $tiplist = t('<p>No guidelines available.</p>');
  }
  $group = t('<p>These are the guidelines that users will see for posting in this input format. They are automatically generated from the filter settings.</p>');
  $group .= $tiplist;
  $output .= '<h2>'. t('Formatting guidelines') .'</h2>'. $group;

Dries's avatar
   
Dries committed
393
  return $output;
394
395
}

396
397
398
399
400
401
402
/**
 * Renders a form for a format
 */
function filter_admin_format_form($format) {
  $edit = $_POST['edit'];

  $default = ($format->format == variable_get('filter_default_format', 1));
403
404
  if ($default) {
    $help = t('All roles for the default format must be enabled and cannot be changed.');
405
    $form['default_format'] = array('#type' => 'hidden', '#value' => 1);
406
  }
407
408

  //Add the name of the object
409
410
  $form['name'] = array('#type' => 'fieldset', '#title' => t('Name'));
  $form['name']['name'] = array('#type' => 'textfield', '#default_value' => $format->name, '#size' => 60, '#maxlength' => 127, '#description' => t('Give the name of this filter format'), '#required' => TRUE);
411
412

  //Add a row of checkboxes for form group
413
  $form['roles'] = array('#type' => 'fieldset', '#title' => t('Roles'), '#description' => $default ? $help : t('Choose which roles may use this filter format.'), '#tree' => TRUE);
414
  $form['roles']['hidden'] = array();
415
416
  foreach (user_roles() as $rid => $name) {
    $checked = strstr($format->roles, ",$rid,");
417
    $form['roles'][$rid] = array('#type' => 'checkbox', '#title' => $name, '#default_value' => ($default || $checked));
418
    if ($default) {
419
      $form['roles'][$rid]['#attributes'] = array('disabled' => 'disabled');
420
    }
421
422
423
424
425
  }
  // Table with filters
  $all = filter_list_all();
  $enabled = filter_list_format($format->format);

426
  $form['filters'] = array('#type' => 'fieldset', '#title' => t('Filters'), '#description' => t('Choose the filters that will be used in this filter format'));
427
  foreach ($all as $id => $filter) {
428
    $form['filters'][$id] = array('#type' => 'checkbox', '#title' => $filter->name, '#default_value' => isset($enabled[$id]), '#description' => module_invoke($filter->module, 'filter', 'description', $filter->delta));
429
430
  }

431
  $form['submit'] = array('#type' => 'submit', '#value' => t('Save configuration'));
432

433
  return drupal_get_form('filter_admin_format_form', $form);
434
435
}

436
437
438
439
440
/**
 * Save enabled/disabled status for filters in a format.
 */
function filter_admin_filters_save($format, $toggles) {
  $current = filter_list_format($format);
441
442
  $edit = $_POST['edit'];
  $name = trim($edit['name']);
443
444
  $cache = true;

445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
  //make sure a title is specified
  if (strlen($name) == 0) {
    form_set_error('name', t('You must enter a name for this input format.'));
   return;
  }

  if (!$format) { //add a new filter format.
    $new = true;
    db_query("INSERT INTO {filter_formats} (name) VALUES ('%s')", $name);
    $result = db_fetch_object(db_query("SELECT MAX(format) AS format FROM {filter_formats}"));
    $format = $result->format;
   drupal_set_message(t('Added input format %format.', array('%format' => theme('placeholder', $edit['name']))));
  }
  else {
    drupal_set_message(t('The input format settings have been updated.'));
  }

462
463
464
465
466
467
468
469
470
471
472
473
474
  db_query("DELETE FROM {filters} WHERE format = %d", $format);
  foreach ($toggles as $id => $checked) {
    if ($checked) {
      list($module, $delta) = explode('/', $id);
      // Add new filters to the bottom
      $weight = isset($current[$id]->weight) ? $current[$id]->weight : 10;
      db_query("INSERT INTO {filters} (format, module, delta, weight) VALUES (%d, '%s', %d, %d)", $format, $module, $delta, $weight);

      // Check if there are any 'no cache' filters
      $cache &= !module_invoke($module, 'filter', 'no cache', $delta);
    }
  }

475
  // We store the roles as a string for ease of use.
476
  // we should always set all roles to true when saving a default role.
477
  // We use leading and trailing comma's to allow easy substring matching.
478
  $roles = isset($edit['roles']) ? array_keys($edit['roles']) : array();
479
  $roles = ','. implode(',', ($edit['default_format'] ? user_roles() : $roles)) .',';
480
481

  db_query("UPDATE {filter_formats} SET cache = %d, name='%s', roles = '%s' WHERE format = %d", $cache, $name, $roles, $format);
482
483
484

  cache_clear_all('filter:'. $format, true);

485
486
487
488
489
490
491
  // if a new filter was added, return to the main list of filters, otherwise stay on edit filter page to show new changes
  if ($new) {
    drupal_goto('admin/filters/');
  }
  else {
    drupal_goto('admin/filters/' . arg(2)) ;
  }
492
493
494
}

/**
495
 * Menu callback; display form for ordering filters for a format.
496
497
498
499
500
 */
function filter_admin_order() {
  $format = arg(2);
  if ($_POST['op']) {
    filter_admin_order_save($format, $_POST['edit']);
Dries's avatar
   
Dries committed
501
502
503
  }

  // Get list (with forced refresh)
504
  $filters = filter_list_format($format);
Dries's avatar
   
Dries committed
505

506
  foreach ($filters as $id => $filter) {
507
508
    $form['name'][$id] = array('#type' => 'markup', '#value' => $filter->name);
    $form['weight'][$id] = array('#type' => 'weight', '#default_value' => $filter->weight);
Dries's avatar
   
Dries committed
509
  }
510
  $form['submit'] = array('#type' => 'submit', '#value' => t('Save configuration'));
Dries's avatar
   
Dries committed
511

512
513
  return drupal_get_form('filter_admin_order', $form);
}
Dries's avatar
   
Dries committed
514

515
516
517
518
519
520
521
522
523
524
525
526
527
528
function theme_filter_admin_order($form) {
  $header = array(t('Name'), t('Weight'));
  $rows = array();
  foreach (element_children($form['name']) as $id) {
    // Don't take form control structures
    if (is_array($form['name'][$id])) {
      $rows[] = array(
        form_render($form['name'][$id]),
        form_render($form['weight'][$id]));
    }
  }

  $output = theme('table', $header, $rows);
  $output .= form_render($form);
Dries's avatar
   
Dries committed
529
  return $output;
Dries's avatar
   
Dries committed
530
531
}

Dries's avatar
Dries committed
532
/**
533
534
535
536
537
 * Save the weights of filters in a format.
 */
function filter_admin_order_save($format, $weights) {
  foreach ($weights as $id => $weight) {
    list($module, $delta) = explode('/', $id);
Dries's avatar
   
Dries committed
538
    db_query("UPDATE {filters} SET weight = %d WHERE format = %d AND module = '%s' AND delta = %d", $weight, $format, $module, $delta);
539
  }
540
  drupal_set_message(t('The filter ordering has been saved.'));
541
542

  cache_clear_all('filter:'. $format, true);
543
  drupal_goto($_GET['q']);
544
545
546
}

/**
547
 * Menu callback; display settings defined by filters.
Dries's avatar
Dries committed
548
 */
549
550
551
552
function filter_admin_configure() {
  $format = arg(2);

  $list = filter_list_format($format);
553
  $form = array();
554
  foreach ($list as $filter) {
555
    $form = array_merge($form, module_invoke($filter->module, 'filter', 'settings', $filter->delta, $format));
556
  }
Dries's avatar
   
Dries committed
557

558
559
  if (!empty($form)) {
    $output = system_settings_form('filter_admin_configure', $form);
560
561
562
563
  }
  else {
    $output = t('No settings are available.');
  }
Dries's avatar
   
Dries committed
564

Dries's avatar
   
Dries committed
565
  return $output;
566
567
}

Dries's avatar
Dries committed
568
/**
569
 * Retrieve a list of input formats.
Dries's avatar
Dries committed
570
 */
571
572
573
574
575
576
577
578
579
580
function filter_formats() {
  global $user;
  static $formats;

  // Administrators can always use all input formats.
  $all = user_access('administer filters');

  if (!isset($formats)) {
    $formats = array();

581
    $query = 'SELECT * FROM {filter_formats}';
582

583
    // Build query for selecting the format(s) based on the user's roles.
584
585
586
587
    if (!$all) {
      $where = array();
      foreach ($user->roles as $rid => $role) {
        $where[] = "roles LIKE '%%,%d,%%'";
588
        $args[] = $rid;
589
      }
590
591
      $query .= ' WHERE '. implode(' OR ', $where) . ' OR format = %d';
      $args[] = variable_get('filter_default_format', 1);
592
593
    }

594
    $result = db_query($query, $args);
595
596
597
598
599
600
    while ($format = db_fetch_object($result)) {
      $formats[$format->format] = $format;
    }
  }
  return $formats;
}
601

602
603
604
605
606
607
608
609
610
611
612
613
/**
 * Build a list of all filters.
 */
function filter_list_all() {
  $filters = array();

  foreach (module_list() as $module) {
    $list = module_invoke($module, 'filter', 'list');
    if (is_array($list)) {
      foreach ($list as $delta => $name) {
        $filters[$module .'/'. $delta] = (object)array('module' => $module, 'delta' => $delta, 'name' => $name);
      }
Dries's avatar
   
Dries committed
614
615
616
    }
  }

617
618
619
620
621
622
623
624
625
626
  uasort($filters, '_filter_list_cmp');

  return $filters;
}

/**
 * Helper function for sorting the filter list by filter name.
 */
function _filter_list_cmp($a, $b) {
  return strcmp($a->name, $b->name);
Dries's avatar
   
Dries committed
627
628
}

Dries's avatar
Dries committed
629
/**
630
 * Check if text in a certain input format is allowed to be cached.
Dries's avatar
Dries committed
631
 */
632
633
function filter_format_allowcache($format) {
  static $cache = array();
Dries's avatar
   
Dries committed
634

635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
  if (!isset($cache[$format])) {
    $cache[$format] = db_result(db_query('SELECT cache FROM {filter_formats} WHERE format = %d', $format));
  }
  return $cache[$format];
}

/**
 * Retrieve a list of filters for a certain format.
 */
function filter_list_format($format) {
  static $filters = array();

  if (!is_array($filters[$format])) {
    $filters[$format] = array();
    $result = db_query("SELECT * FROM {filters} WHERE format = %d ORDER BY weight ASC", $format);
    while ($filter = db_fetch_object($result)) {
      $list = module_invoke($filter->module, 'filter', 'list');
      if (is_array($list) && isset($list[$filter->delta])) {
        $filter->name = $list[$filter->delta];
        $filters[$format][$filter->module .'/'. $filter->delta] = $filter;
Dries's avatar
   
Dries committed
655
656
657
658
      }
    }
  }

659
  return $filters[$format];
660
661
}

662
663
/**
 * @name Filtering functions
Dries's avatar
   
Dries committed
664
 * @{
665
666
 * Modules which need to have content filtered can use these functions to
 * interact with the filter system.
667
668
669
670
671
672
673
674
 *
 * For more info, see the hook_filter() documentation.
 *
 * Note: because filters can inject JavaScript or execute PHP code, security is
 * vital here. When a user supplies a $format, you should validate it with
 * filter_access($format) before accepting/using it. This is normally done in
 * the validation stage of the node system. You should for example never make a
 * preview of content in a disallowed format.
675
676
 */

Dries's avatar
Dries committed
677
678
/**
 * Run all the enabled filters on a piece of text.
679
680
681
682
683
684
685
686
687
688
689
690
 *
 * @param $text
 *    The text to be filtered.
 * @param $format
 *    The format of the text to be filtered. Specify FILTER_FORMAT_DEFAULT for
 *    the default format.
 * @param $check
 *    Whether to check the $format with filter_access() first. Defaults to TRUE.
 *    Note that this will check the permissions of the current user, so you
 *    should specify $check = FALSE when viewing other people's content.  When
 *    showing content that is not (yet) stored in the database (eg. upon preview),
 *    set to TRUE so the user's permissions are checked.
Dries's avatar
Dries committed
691
 */
692
function check_markup($text, $format = FILTER_FORMAT_DEFAULT, $check = TRUE) {
693
694
  // When $check = true, do an access check on $format.
  if (isset($text) && (!$check || filter_access($format))) {
695
696
697
698
    if ($format == FILTER_FORMAT_DEFAULT) {
      $format = variable_get('filter_default_format', 1);
    }

699
    // Check for a cached version of this piece of text.
700
701
702
703
704
    $id = 'filter:'. $format .':'. md5($text);
    if ($cached = cache_get($id)) {
      return $cached->data;
    }

705
    // See if caching is allowed for this format.
706
    $cache = filter_format_allowcache($format);
707
708

    // Convert all Windows and Mac newlines to a single newline,
709
    // so filters only need to deal with one possibility.
710
711
    $text = str_replace(array("\r\n", "\r"), "\n", $text);

712
    // Get a complete list of filters, ordered properly.
713
    $filters = filter_list_format($format);
Dries's avatar
   
Dries committed
714

Dries's avatar
Dries committed
715
    // Give filters the chance to escape HTML-like data such as code or formulas.
716
717
    foreach ($filters as $filter) {
      $text = module_invoke($filter->module, 'filter', 'prepare', $filter->delta, $format, $text);
Dries's avatar
   
Dries committed
718
    }
719

720
    // Perform filtering.
721
722
    foreach ($filters as $filter) {
      $text = module_invoke($filter->module, 'filter', 'process', $filter->delta, $format, $text);
723
724
    }

725
    // Store in cache with a minimum expiration time of 1 day.
Dries's avatar
Dries committed
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
    if ($cache) {
      cache_set($id, $text, time() + (60 * 60 * 24));
    }
  }
  else {
    $text = message_na();
  }

  return $text;
}

/**
 * Generate a selector for choosing a format in a form.
 *
 * @param $name
 *   The internal name used to refer to the form element.
 * @param $value
 *   The ID of the format that is currently selected.
 * @return
 *   HTML for the form element.
 */
747
function filter_form($value = FILTER_FORMAT_DEFAULT) {
Dries's avatar
Dries committed
748
749
750
751
752
753
754
755
  if ($value == FILTER_FORMAT_DEFAULT) {
    $value = variable_get('filter_default_format', 1);
  }
  $formats = filter_formats();

  $extra = l(t('More information about formatting options'), 'filter/tips');

  if (count($formats) > 1) {
756
    $form['format'] = array('#type' => 'fieldset', '#title' => t('Input format'), '#collapsible' => TRUE, '#collapsed' => TRUE, '#weight' => -4);
Dries's avatar
Dries committed
757
758
    // Multiple formats available: display radio buttons with tips.
    foreach ($formats as $format) {
759
      $form['format'][$format->format] = array('#type' => 'filter_format', '#title' => $format->name, '#default_value' => $value, '#return_value' => $format->format, '#parents' => array('format'), '#description' => theme('filter_tips', _filter_tips($format->format, false)), '#valid' => 'filter_form');
Dries's avatar
Dries committed
760
    }
761
    return $form;
Dries's avatar
Dries committed
762
763
764
765
  }
  else {
    // Only one format available: use a hidden form item and only show tips.
    $format = array_shift($formats);
766
    $form['format'][$format->name] = array('#type' => 'value', '#value' => $format->format);
Dries's avatar
Dries committed
767
    $tips = _filter_tips(variable_get('filter_default_format', 1), false);
768
    $form['format']['guidelines'] = array('#type' => 'markup', '#title' => t('Formatting guidelines'), '#value' => theme('filter_tips', $tips, false, $extra));
769
    return $form;
Dries's avatar
Dries committed
770
771
772
  }
}

773
function filter_elements() {
774
  $type['filter_format'] = array('#input' => TRUE);
775
776
777
778
779
  return $type;
}

function theme_filter_format($element) {
  $output .= '<div>';
780
781
  $output .= '<label class="option"><input type="radio" class="form-radio" name="' . $element['#name'] . '" value="'. $element['#return_value'] .'"'. (($element['#default_value'] == $element['#return_value']) ? ' checked="checked"' : '') .' /> '. $element['#title'] .'</label>';
  $output .= $element['#description'];
782
783
784
785
  $output .= '</div>';
  return $output;
}

786
787
788
789
790
791
792
793
794
795
796
function filter_form_valid($element) {
  static $validated;
  if ($validated) {
    return;
  }
  $validated = 1;
  $formats = filter_formats();
  if (!isset($formats[$element['#value']])) {
    form_set_error($element['#parents'][0], t('The supplied input format is invalid.'));
  }
}
797

Dries's avatar
Dries committed
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
/**
 * Returns true if the user is allowed to access this format.
 */
function filter_access($format) {
  if (user_access('administer filters') || ($format == FILTER_FORMAT_DEFAULT) || ($format == variable_get('filter_default_format', 1))) {
    return true;
  }
  else {
    $formats = filter_formats();
    return isset($formats[$format]);
  }
}
/**
 * @} End of "Filtering functions".
 */

/**
 * Menu callback; show a page with long filter tips.
 */
function filter_tips_long() {
  $format = arg(2);
  if ($format) {
    $output = theme('filter_tips', _filter_tips($format, true), true);
  }
  else {
    $output = theme('filter_tips', _filter_tips(-1, true), true);
  }
  return $output;
}

/**
 * Helper function for fetching filter tips.
 */
function _filter_tips($format, $long = false) {
  if ($format == -1) {
    $formats = filter_formats();
  }
  else {
    $formats = array(db_fetch_object(db_query("SELECT * FROM {filter_formats} WHERE format = %d", $format)));
  }

  $tips = array();

  foreach ($formats as $format) {
    $filters = filter_list_format($format->format);

    $tips[$format->name] = array();
    foreach ($filters as $id => $filter) {
      if ($tip = module_invoke($filter->module, 'filter_tips', $filter->delta, $format->format, $long)) {
        $tips[$format->name][] = array('tip' => $tip, 'id' => $id);
      }
    }
  }

  return $tips;
}

/**
 * Format a set of filter tips.
 *
 * @ingroup themeable
 */
function theme_filter_tips($tips, $long = false, $extra = '') {
  $output = '';

  $multiple = count($tips) > 1;
  if ($multiple) {
865
    $output = t('input formats') .':';
Dries's avatar
Dries committed
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
  }

  if (count($tips)) {
    if ($multiple) {
      $output .= '<ul>';
    }
    foreach ($tips as $name => $tiplist) {
      if ($multiple) {
        $output .= '<li>';
        $output .= '<strong>'. $name .'</strong>:<br />';
      }

      $tips = '';
      foreach ($tiplist as $tip) {
        $tips .= '<li'. ($long ? ' id="filter-'. str_replace("/", "-", $tip['id']) .'">' : '>') . $tip['tip'] . '</li>';
      }

      if ($tips) {
        $output .= "<ul class=\"tips\">$tips</ul>";
      }

      if ($multiple) {
        $output .= '</li>';
      }
    }
    if ($multiple) {
      $output .= '</ul>';
    }
  }

  return $output;
}

/**
 * @name Standard filters
 * @{
 * Filters implemented by the filter.module.
 */

/**
 * Implementation of hook_filter(). Contains a basic set of essential filters.
 * - HTML filter:
 *     Validates user-supplied HTML, transforming it as necessary.
 * - PHP evaluator:
 *     Executes PHP code.
 * - Line break converter:
 *     Converts newlines into paragraph and break tags.
 */
function filter_filter($op, $delta = 0, $format = -1, $text = '') {
  switch ($op) {
    case 'list':
      return array(0 => t('HTML filter'), 1 => t('PHP evaluator'), 2 => t('Line break converter'));

    case 'no cache':
      return $delta == 1; // No caching for the PHP evaluator.

    case 'description':
      switch ($delta) {
        case 0:
          return t('Allows you to restrict if users can post HTML and which tags to filter out.');
        case 1:
          return t('Runs a piece of PHP code. The usage of this filter should be restricted to administrators only!');
        case 2:
          return t('Converts line breaks into HTML (i.e. &lt;br&gt; and &lt;p&gt; tags).');
        default:
          return;
      }

    case 'process':
      switch ($delta) {
        case 0:
          return _filter_html($text, $format);
        case 1:
          return drupal_eval($text);
        case 2:
          return _filter_autop($text);
        default:
          return $text;
      }

    case 'settings':
      switch ($delta) {
        case 0:
          return _filter_html_settings($format);
        default:
          return;
      }

    default:
      return $text;
  }
}

/**
 * Settings for the HTML filter.
 */
function _filter_html_settings($format) {
963
964
965
966
967
968
  $form['filter_html'] = array('#type' => 'fieldset', '#title' => t('HTML filter'), '#collapsible' => TRUE, '#collapsed' => TRUE);
  $form['filter_html']["filter_html_$format"] = array('#type' => 'radios', '#title' => t('Filter HTML tags'), '#default_value' => variable_get("filter_html_$format", FILTER_HTML_STRIP), '#options' => array(FILTER_HTML_STRIP => t('Strip tags'), FILTER_HTML_ESCAPE => t('Escape tags')), '#description' => t('How to deal with HTML tags in user-contributed content. If set to "Strip tags", dangerous tags are removed (see below). If set to "Escape tags", all HTML is escaped and presented as it was typed.'));
  $form['filter_html']["allowed_html_$format"] = array('#type' => 'textfield', '#title' => t('Allowed HTML tags'), '#default_value' => variable_get("allowed_html_$format", '<a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>'), '#size' => 64, '#maxlength' => 255, '#description' => t('If "Strip tags" is selected, optionally specify tags which should not be stripped. Javascript event attributes are always stripped.'));
  $form['filter_html']["filter_html_help_$format"] = array('#type' => 'checkbox', '#title' => t('Display HTML help'), '#default_value' => variable_get("filter_html_help_$format", 1), '#description' => t('If enabled, Drupal will display some basic HTML help in the long filter tips.'));
  $form['filter_html']["filter_style_$format"] = array('#type' => 'radios', '#title' => t('HTML style attributes'), '#default_value' => variable_get("filter_style_$format", FILTER_STYLE_STRIP), '#options' => array(FILTER_STYLE_ALLOW => t('Allowed'), FILTER_STYLE_STRIP => t('Removed')), '#description' => t('If "Strip tags" is selected, you can choose whether "STYLE" attributes are allowed or removed from input.'));
  $form['filter_html']["filter_html_nofollow_$format"] = array('#type' => 'checkbox', '#title' => t('Spam link deterrent'), '#default_value' => variable_get("filter_html_nofollow_$format", FALSE), '#description' => t('If enabled, Drupal will add rel="nofollow" to all links, as a measure to reduce the effectiveness of spam links. Note: this will also prevent valid links from being followed by search engines, therefore it is likely most effective when enabled for anonymous users.'));
969
970

  return $form;
Dries's avatar
Dries committed
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
}

/**
 * HTML filter. Provides filtering of input into accepted HTML.
 */
function _filter_html($text, $format) {
  if (variable_get("filter_html_$format", FILTER_HTML_STRIP) == FILTER_HTML_STRIP) {
    // Allow users to enter HTML, but filter it
    $text = strip_tags($text, variable_get("allowed_html_$format", '<a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>'));
    if (variable_get("filter_style_$format", FILTER_STYLE_STRIP)) {
      $text = preg_replace('/\Wstyle\s*=[^>]+?>/i', '>', $text);
    }
    $text = preg_replace('/\Won[a-z]+\s*=[^>]+?>/i', '>', $text);
  }

  if (variable_get("filter_html_$format", FILTER_HTML_STRIP) == FILTER_HTML_ESCAPE) {
    // Escape HTML
    $text = check_plain($text);
  }

  if (variable_get("filter_html_nofollow_$format", FALSE)) {
    $text = preg_replace('/<a([^>]+)>/i', '<a\\1 rel="nofollow">', $text);
  }

  return trim($text);
}

/**
 * Convert line breaks into <p> and <br> in an intelligent fashion.
 * Based on: http://photomatt.net/scripts/autop
 */
function _filter_autop($text) {
  // Split at <pre>, <script>, <style> and </pre>, </script>, </style> tags.
  // We don't apply any processing to the contents of these tags to avoid messing
  // up code. We look for matched pairs and allow basic nesting. For example:
  // "processed <pre> ignored <script> ignored </script> ignored </pre> processed"
  $chunks = preg_split('@(</?(?:pre|script|style)[^>]*>)@i', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
  // Note: PHP ensures the array consists of alternating delimiters and literals
  // and begins and ends with a literal (inserting NULL as required).
  $ignore = false;
  $ignoretag = '';
  $output = '';
  foreach ($chunks as $i => $chunk) {
    if ($i % 2) {
      // Opening or closing tag?
      $open = ($chunk{1} != '/');
      list($tag) = split('[ >]', substr($chunk, 2 - $open), 2);
      if (!$ignore) {
        if ($open) {
          $ignore = true;
          $ignoretag = $tag;
        }
      }
      // Only allow a matching tag to close it.
      else if (!$open && $ignoretag == $tag) {
        $ignore = false;
        $ignoretag = '';
      }
    }
    else if (!$ignore) {
      $chunk = preg_replace('|\n*$|', '', $chunk) ."\n\n"; // just to make things a little easier, pad the end
      $chunk = preg_replace('|<br />\s*<br />|', "\n\n", $chunk);
      $chunk = preg_replace('!(<(?:table|ul|ol|li|pre|form|blockquote|h[1-6])[^>]*>)!', "\n$1", $chunk); // Space things out a little
      $chunk = preg_replace('!(</(?:table|ul|ol|li|pre|form|blockquote|h[1-6])>)!', "$1\n", $chunk); // Space things out a little
      $chunk = preg_replace("/\n\n+/", "\n\n", $chunk); // take care of duplicates
      $chunk = preg_replace('/\n?(.+?)(?:\n\s*\n|\z)/s', "<p>$1</p>\n", $chunk); // make paragraphs, including one at the end
      $chunk = preg_replace('|<p>\s*?</p>|', '', $chunk); // under certain strange conditions it could create a P of entirely whitespace
      $chunk = preg_replace("|<p>(<li.+?)</p>|", "$1", $chunk); // problem with nested lists
      $chunk = preg_replace('|<p><blockquote([^>]*)>|i', "<blockquote$1><p>", $chunk);
      $chunk = str_replace('</blockquote></p>', '</p></blockquote>', $chunk);
      $chunk = preg_replace('!<p>\s*(</?(?:table|tr|td|th|div|ul|ol|li|pre|select|form|blockquote|p|h[1-6])[^>]*>)!', "$1", $chunk);
      $chunk = preg_replace('!(</?(?:table|tr|td|th|div|ul|ol|li|pre|select|form|blockquote|p|h[1-6])[^>]*>)\s*</p>!', "$1", $chunk);
      $chunk = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $chunk); // make line breaks
      $chunk = preg_replace('!(</?(?:table|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|select|form|blockquote|p|h[1-6])[^>]*>)\s*<br />!', "$1", $chunk);
      $chunk = preg_replace('!<br />(\s*</?(?:p|li|div|th|pre|td|ul|ol)>)!', '$1', $chunk);
      $chunk = preg_replace('/&([^#])(?![a-z]{1,8};)/', '&amp;$1', $chunk);
    }
    $output .= $chunk;
  }
  return $output;
}

/**
 * @} End of "Standard filters".
 */