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) {
284 285 286 287 288 289 290
    $roles = array();
    foreach (user_roles() as $rid => $name) {
      //prepare a roles array with roles that may access the filter
      if (strstr($format->roles, ",$rid,")){
        $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.
478 479
  $roles = isset($edit['roles']) ? $edit['roles'] : array();
  $roles = ','. implode(',', ($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
  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');

755
  $form['format'] = array('#type' => 'fieldset', '#title' => t('Input format'), '#collapsible' => TRUE, '#collapsed' => TRUE, '#weight' => -4);
Dries's avatar
Dries committed
756 757 758
  if (count($formats) > 1) {
    // 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".
 */