link.module

   1 <?php
   2 // $Id$
   3
   4 /**
   5  * @file
   6  * Defines simple link field types.
   7  */
   8
   9 define('LINK_EXTERNAL', 'external');
  10 define('LINK_INTERNAL', 'internal');
  11 define('LINK_FRONT', 'front');
  12 define('LINK_EMAIL', 'email');
  13 define('LINK_DOMAINS', 'aero|arpa|biz|com|cat|coop|edu|gov|info|int|jobs|mil|museum|name|nato|net|org|pro|travel|mobi');
  14
  15 /**
  16  * Implementation of hook_field_info().
  17  */
  18 function link_field_info() {
  19   return array(
  20     'link' => array(
  21       'label' => t('Link'),
  22       'description' => t('Store a title, href, and attributes in the database to assemble a link.'),
  23     ),
  24   );
  25 }
  26
  27 /**
  28  * Implementation of hook_field_settings().
  29  */
  30 function link_field_settings($op, $field) {
  31   switch ($op) {
  32     case 'form':
  33       $form = array(
  34         '#theme' => 'link_field_settings',
  35       );
  36
  37       $form['url'] = array(
  38         '#type' => 'checkbox',
  39         '#title' => t('Optional URL'),
  40         '#default_value' => $field['url'],
  41         '#return_value' => 'optional',
  42         '#description' => t('If checked, the URL field is optional and submitting a title alone will be acceptable. If the URL is ommitted, the title will be displayed as plain text.'),
  43       );
  44
  45       $title_options = array(
  46         'optional' => t('Optional Title'),
  47         'required' => t('Required Title'),
  48         'value' => t('Static Title: '),
  49         'none' => t('No Title'),
  50       );
  51
  52       $form['title'] = array(
  53         '#type' => 'radios',
  54         '#title' => t('Link Title'),
  55         '#default_value' => isset($field['title']) ? $field['title'] : 'optional',
  56         '#options' => $title_options,
  57         '#description' => t('If the link title is optional or required, a field will be displayed to the end user. If the link title is static, the link will always use the same title. If <a href="http://drupal.org/project/token">token module</a> is installed, the static title value may use any other node field as its value. Static and token-based titles may include most inline XHTML tags such as <em>strong</em>, <em>em</em>, <em>img</em>, <em>span</em>, etc.'),
  58       );
  59
  60       $form['title_value'] = array(
  61         '#type' => 'textfield',
  62         '#default_value' => $field['title_value'],
  63         '#size' => '46',
  64       );
  65
  66       // Add token module replacements if available
  67       if (module_exists('token')) {
  68         $form['tokens'] = array(
  69           '#type' => 'fieldset',
  70           '#collapsible' => TRUE,
  71           '#collapsed' => TRUE,
  72           '#title' => t('Placeholder tokens'),
  73           '#description' => t("The following placeholder tokens can be used in both paths and titles. When used in a path or title, they will be replaced with the appropriate values."),
  74         );
  75         $form['tokens']['help'] = array(
  76           '#value' => theme('token_help', 'node'),
  77         );
  78
  79         $form['enable_tokens'] = array(
  80           '#type' => 'checkbox',
  81           '#title' => t('Allow user-entered tokens'),
  82           '#default_value' => isset($field['enable_tokens']) ? $field['enable_tokens'] : 1,
  83           '#description' => t('Checking will allow users to enter tokens in URLs and Titles on the node edit form. This does not affect the field settings on this page.'),
  84         );
  85       }
  86
  87       $form['display'] = array(
  88         '#tree' => true,
  89       );
  90       $form['display']['url_cutoff'] = array(
  91         '#type' => 'textfield',
  92         '#title' => t('URL Display Cutoff'),
  93         '#default_value' => isset($field['display']['url_cutoff']) ? $field['display']['url_cutoff'] : '80',
  94         '#description' => t('If the user does not include a title for this link, the URL will be used as the title. When should the link title be trimmed and finished with an elipsis (&hellip;)? Leave blank for no limit.'),
  95         '#maxlength' => 3,
  96         '#size' => 3,
  97       );
  98
  99       $target_options = array(
 100         'default' => t('Default (no target attribute)'),
 101         '_top' => t('Open link in window root'),
 102         '_blank' => t('Open link in new window'),
 103         'user' => t('Allow the user to choose'),
 104       );
 105       $form['attributes'] = array(
 106         '#tree' => true,
 107       );
 108       $form['attributes']['target'] = array(
 109         '#type' => 'radios',
 110         '#title' => t('Link Target'),
 111         '#default_value' => $field['attributes']['target'] ? $field['attributes']['target'] : 'default',
 112         '#options' => $target_options,
 113       );
 114       $form['attributes']['rel'] = array(
 115         '#type' => 'textfield',
 116         '#title' => t('Rel Attribute'),
 117         '#description' => t('When output, this link will have this rel attribute. The most common usage is <a href="http://en.wikipedia.org/wiki/Nofollow">rel=&quot;nofollow&quot;</a> which prevents some search engines from spidering entered links.'),
 118         '#default_value' => $field['attributes']['rel'] ? $field['attributes']['rel'] : '',
 119         '#field_prefix' => 'rel = "',
 120         '#field_suffix' => '"',
 121         '#size' => 20,
 122       );
 123       $form['attributes']['class'] = array(
 124         '#type' => 'textfield',
 125         '#title' => t('Additional CSS Class'),
 126         '#description' => t('When output, this link will have have this class attribute. Multiple classes should be seperated by spaces.'),
 127         '#default_value' => isset($field['attributes']['class']) ? $field['attributes']['class'] : '',
 128       );
 129       return $form;
 130
 131     case 'validate':
 132       if ($field['title'] == 'value' && empty($field['title_value'])) {
 133         form_set_error('title_value', t('A default title must be provided if the title is a static value'));
 134       }
 135       break;
 136
 137     case 'save':
 138       return array('attributes', 'display', 'url', 'title', 'title_value', 'enable_tokens');
 139
 140     case 'database columns':
 141       return array(
 142         'url' => array('type' => 'varchar', 'length' => 255, 'not null' => FALSE, 'sortable' => TRUE),
 143         'title' => array('type' => 'varchar', 'length' => 255, 'not null' => FALSE, 'sortable' => TRUE),
 144         'attributes' => array('type' => 'text', 'size' => 'medium', 'not null' => FALSE),
 145       );
 146
 147     case 'views data':
 148       if (!empty($field)) {
 149         $data = link_views_data($field);
 150       }
 151       return isset($data) ? $data : NULL;
 152   }
 153 }
 154
 155 /**
 156  * Theme the settings form for the link field.
 157  */
 158 function theme_link_field_settings($form) {
 159   $title_value = drupal_render($form['title_value']);
 160   $title_checkbox = drupal_render($form['title']['value']);
 161
 162   // Set Static Title radio option to include the title_value textfield.
 163   $form['title']['value'] = array('#value' => '<div class="container-inline">'. $title_checkbox . $title_value .'</div>');
 164
 165   // Reprint the title radio options with the included textfield.
 166   return drupal_render($form);
 167 }
 168
 169 /**
 170  * Implementation of hook_content_is_empty().
 171  */
 172 function link_content_is_empty($item, $field) {
 173   if (empty($item['title']) && empty($item['url'])) {
 174     return TRUE;
 175   }
 176   return FALSE;
 177 }
 178
 179 /**
 180  * Implementation of hook_field().
 181  */
 182 function link_field($op, &$node, $field, &$items, $teaser, $page) {
 183   switch ($op) {
 184     case 'load':
 185       foreach ($items as $delta => $item) {
 186         _link_load($items[$delta], $delta);
 187       }
 188       return $items;
 189       break;
 190
 191     case 'validate':
 192       $optional_field_found = FALSE;
 193       foreach($items as $delta => $value) {
 194         _link_validate($items[$delta],$delta, $field, $node, $optional_field_found);
 195       }
 196
 197       if ($field['url'] == 'optional' && $field['title'] == 'optional' && $field['required'] && !$optional_field_found) {
 198         form_set_error($field['field_name'] .'][0][title', t('At least one title or URL must be entered.'));
 199       }
 200       break;
 201
 202     case 'process form values':
 203       foreach($items as $delta => $value) {
 204         _link_process($items[$delta],$delta, $field, $node);
 205       }
 206       break;
 207
 208     case 'sanitize':
 209       foreach ($items as $delta => $value) {
 210         _link_sanitize($items[$delta], $delta, $field, $node);
 211       }
 212       break;
 213   }
 214 }
 215
 216 /**
 217  * Implementation of hook_widget_info().
 218  */
 219 function link_widget_info() {
 220   return array(
 221     'link' => array(
 222       'label' => 'Text Fields for Title and URL',
 223       'field types' => array('link'),
 224       'multiple values' => CONTENT_HANDLE_CORE,
 225     ),
 226   );
 227 }
 228
 229 /**
 230  * Implementation of hook_widget().
 231  */
 232 function link_widget(&$form, &$form_state, $field, $items, $delta = 0) {
 233   $element = array(
 234     '#type' => $field['widget']['type'],
 235     '#default_value' => isset($items[$delta]) ? $items[$delta] : '',
 236     '#title' => $field['widget']['label'],
 237     '#weight' => $field['widget']['weight'],
 238     '#description' => $field['widget']['description'],
 239     '#required' => $field['required'],
 240     '#field' => $field,
 241   );
 242   return $element;
 243 }
 244
 245 function _link_load(&$item, $delta = 0) {
 246   // Unserialize the attributes array.
 247   $item['attributes'] = unserialize($item['attributes']);
 248 }
 249
 250 function _link_process(&$item, $delta = 0, $field, $node) {
 251   // Remove the target attribute if not selected.
 252   if (!$item['attributes']['target'] || $item['attributes']['target'] == "default") {
 253     unset($item['attributes']['target']);
 254   }
 255   // Trim whitespace from URL.
 256   $item['url'] = trim($item['url']);
 257   // Serialize the attributes array.
 258   $item['attributes'] = serialize($item['attributes']);
 259
 260   // Don't save an invalid default value (e.g. 'http://').
 261   if ((isset($field['widget']['default_value'][$delta]['url']) && $item['url'] == $field['widget']['default_value'][$delta]['url']) && is_object($node)) {
 262     if (!link_validate_url($item['url'])) {
 263       unset($item['url']);
 264     }
 265   }
 266 }
 267
 268 function _link_validate(&$item, $delta, $field, $node, &$optional_field_found) {
 269   if ($item['url'] && !(isset($field['widget']['default_value'][$delta]['url']) && $item['url'] == $field['widget']['default_value'][$delta]['url'] && !$field['required'])) {
 270     // Validate the link.
 271     if (link_validate_url(trim($item['url'])) == FALSE) {
 272       form_set_error($field['field_name'] .']['. $delta. '][url', t('Not a valid URL.'));
 273     }
 274     // Require a title for the link if necessary.
 275     if ($field['title'] == 'required' && strlen(trim($item['title'])) == 0) {
 276       form_set_error($field['field_name'] .']['. $delta. '][title', t('Titles are required for all links.'));
 277     }
 278   }
 279   // Require a link if we have a title.
 280   if ($field['url'] !== 'optional' && strlen($item['title']) > 0 && strlen(trim($item['url'])) == 0) {
 281     form_set_error($field['field_name'] .']['. $delta. '][url', t('You cannot enter a title without a link url.'));
 282   }
 283   // In a totally bizzaro case, where URLs and titles are optional but the field is required, ensure there is at least one link.
 284   if ($field['url'] == 'optional' && $field['title'] == 'optional' && (strlen(trim($item['url'])) != 0 || strlen(trim($item['title'])) != 0)) {
 285     $optional_field_found = TRUE;
 286   }
 287 }
 288
 289 /**
 290  * Cleanup user-entered values for a link field according to field settings.
 291  *
 292  * @param $item
 293  *   A single link item, usually containing url, title, and attributes.
 294  * @param $delta
 295  *   The delta value if this field is one of multiple fields.
 296  * @param $field
 297  *   The CCK field definition.
 298  * @param $node
 299  *   The node containing this link.
 300  */
 301 function _link_sanitize(&$item, $delta, &$field, &$node) {
 302   // Don't try to process empty links.
 303   if (empty($item['url']) && empty($item['title'])) {
 304     return;
 305   }
 306
 307   // Replace URL tokens.
 308   if (module_exists('token') && $field['enable_tokens']) {
 309     $token_node = node_load($node->nid); // Necessary for nodes in views.
 310     $item['url'] = token_replace($item['url'], 'node', $token_node);
 311   }
 312
 313   $type = link_validate_url($item['url']);
 314   $url = link_cleanup_url($item['url']);
 315
 316   // Seperate out the anchor if any.
 317   if (strpos($url, '#') !== FALSE) {
 318     $item['fragment'] = substr($url, strpos($url, '#') + 1);
 319     $url = substr($url, 0, strpos($url, '#'));
 320   }
 321   // Seperate out the query string if any.
 322   if (strpos($url, '?') !== FALSE) {
 323     $item['query'] = substr($url, strpos($url, '?') + 1);
 324     $url = substr($url, 0, strpos($url, '?'));
 325   }
 326   // Save the new URL without the anchor or query.
 327   $item['url'] = $url;
 328
 329   // Create a shortened URL for display.
 330   $display_url = $type == LINK_EMAIL ? str_replace('mailto:', '', $url) : url($url, array('query' => isset($item['query']) ? $item['query'] : NULL, 'fragment' => isset($item['fragment']) ? $item['fragment'] : NULL, 'absolute' => TRUE));
 331   if ($field['display']['url_cutoff'] && strlen($display_url) > $field['display']['url_cutoff']) {
 332     $display_url = substr($display_url, 0, $field['display']['url_cutoff']) . "...";
 333   }
 334   $item['display_url'] = $display_url;
 335
 336   // Use the title defined at the field level.
 337   if ($field['title'] == 'value' && strlen(trim($field['title_value']))) {
 338     $title = $field['title_value'];
 339   }
 340   // Use the title defined by the user at the widget level.
 341   else {
 342     $title = $item['title'];
 343   }
 344   // Replace tokens.
 345   if (module_exists('token') && ($field['title'] == 'value' || $field['enable_tokens'])) {
 346     $token_node = node_load($node->nid); // Necessary for nodes in views.
 347     $title = filter_xss(token_replace($title, 'node', $token_node), array('b', 'br', 'code', 'em', 'i', 'img', 'span', 'strong', 'sub', 'sup', 'tt', 'u'));
 348     $item['html'] = TRUE;
 349   }
 350   $item['display_title'] = empty($title) ? $item['display_url'] : $title;
 351
 352   // Add attributes defined at the widget level
 353   $attributes = array();
 354   if (is_array($item['attributes'])) {
 355     foreach($item['attributes'] as $attribute => $attbvalue) {
 356       if (isset($item['attributes'][$attribute]) && $field['attributes'][$attribute] == 'user') {
 357         $attributes[$attribute] = $attbvalue;
 358        }
 359      }
 360    }
 361   // Add attributes defined at the field level
 362   if (is_array($field['attributes'])) {
 363     foreach($field['attributes'] as $attribute => $attbvalue) {
 364       if (!empty($attbvalue) && $attbvalue != 'default' && $attbvalue != 'user') {
 365         $attributes[$attribute] = $attbvalue;
 366       }
 367     }
 368   }
 369   // Remove the rel=nofollow for internal links.
 370   if ($type != LINK_EXTERNAL && isset($attributes['rel']) && strpos($attributes['rel'], 'nofollow') !== FALSE) {
 371     $attributes['rel'] = str_replace('nofollow', '', $attributes['rel']);
 372     if (empty($attributes['rel'])) {
 373       unset($attributes['rel']);
 374     }
 375   }
 376   $item['attributes'] = $attributes;
 377
 378   // Add the widget label.
 379   $item['label'] = $field['widget']['label'];
 380 }
 381
 382 /**
 383  * Implementation of hook_theme().
 384  */
 385 function link_theme() {
 386   return array(
 387     'link_field_settings' => array(
 388       'arguments' => array('element' => NULL),
 389     ),
 390     'link_formatter_default' => array(
 391       'arguments' => array('element' => NULL),
 392     ),
 393     'link_formatter_plain' => array(
 394       'arguments' => array('element' => NULL),
 395     ),
 396     'link_formatter_url' => array(
 397       'arguments' => array('element' => NULL),
 398     ),
 399     'link_formatter_short' => array(
 400       'arguments' => array('element' => NULL),
 401     ),
 402     'link_formatter_label' => array(
 403       'arguments' => array('element' => NULL),
 404     ),
 405     'link_formatter_separate' => array(
 406       'arguments' => array('element' => NULL),
 407     ),
 408     'link' => array(
 409       'arguments' => array('element' => NULL),
 410     ),
 411   );
 412 }
 413
 414 /**
 415  * FAPI theme for an individual text elements.
 416  */
 417 function theme_link($element) {
 418   drupal_add_css(drupal_get_path('module', 'link') .'/link.css');
 419
 420   // Prefix single value link fields with the name of the field.
 421   if (empty($element['#field']['multiple'])) {
 422     if (isset($element['url']) && isset($element['title'])) {
 423       $element['url']['#title'] = $element['#title'] .' '. $element['url']['#title'];
 424       $element['title']['#title'] = $element['#title'] .' '. $element['title']['#title'];
 425     }
 426     elseif($element['url']) {
 427       $element['url']['#title'] = $element['#title'];
 428     }
 429   }
 430
 431   $output = '';
 432   $output .= '<div class="link-field-subrow clear-block">';
 433   if (isset($element['title'])) {
 434     $output .= '<div class="link-field-title link-field-column">' . theme('textfield', $element['title']) . '</div>';
 435   }
 436   $output .= '<div class="link-field-url' . (isset($element['title']) ? ' link-field-column' : '') . '">' . theme('textfield', $element['url']) . '</div>';
 437   $output .= '</div>';
 438   if (!empty($element['attributes'])) {
 439     $output .= '<div class="link-attributes">' . theme('form_element', $element['attributes'], $element['attributes']['#value']) . '</div>';
 440   }
 441   return $output;
 442 }
 443
 444 /**
 445  * Implementation of hook_elements().
 446  */
 447 function link_elements() {
 448   $elements = array();
 449   $elements['link'] =  array(
 450     '#input' => TRUE,
 451     '#columns' => array('url', 'title'),
 452     '#process' => array('link_process'),
 453   );
 454   return $elements;
 455 }
 456
 457 /**
 458  * Process the link type element before displaying the field.
 459  *
 460  * Build the form element. When creating a form using FAPI #process,
 461  * note that $element['#value'] is already set.
 462  *
 463  * The $fields array is in $form['#field_info'][$element['#field_name']].
 464  */
 465 function link_process($element, $edit, $form_state, $form) {
 466    $field = $form['#field_info'][$element['#field_name']];
 467    $delta = $element['#delta'];
 468    $element['url'] = array(
 469      '#type' => 'textfield',
 470      '#maxlength' => '255',
 471      '#title' => t('URL'),
 472      '#description' => $element['#description'],
 473      '#required' => ($delta == 0 && $field['url'] !== 'optional') ? $element['#required'] : FALSE,
 474      '#default_value' => isset($element['#value']['url']) ? $element['#value']['url'] : NULL,
 475    );
 476    if ($field['title'] != 'none' && $field['title'] != 'value') {
 477      $element['title'] = array(
 478        '#type' => 'textfield',
 479        '#maxlength' => '255',
 480        '#title' => t('Title'),
 481        '#required' => ($delta == 0 && $field['title'] == 'required') ? $field['required'] : FALSE,
 482        '#default_value' => isset($element['#value']['title']) ? $element['#value']['title'] : NULL,
 483      );
 484    }
 485    if ($field['attributes']['target'] == 'user') {
 486      $element['attributes']['target'] = array(
 487        '#type' => 'checkbox',
 488        '#title' => t('Open URL in a New Window'),
 489        '#return_value' => "_blank",
 490      );
 491    }
 492    return $element;
 493 }
 494
 495 /**
 496  * Implementation of hook_field_formatter_info().
 497  */
 498 function link_field_formatter_info() {
 499   return array(
 500     'default' => array(
 501       'label' => t('Title, as link (default)'),
 502       'field types' => array('link'),
 503       'multiple values' => CONTENT_HANDLE_CORE,
 504     ),
 505     'url' => array(
 506       'label' => t('URL, as link'),
 507       'field types' => array('link'),
 508       'multiple values' => CONTENT_HANDLE_CORE,
 509     ),
 510     'plain' => array(
 511       'label' => t('URL, as plain text'),
 512       'field types' => array('link'),
 513       'multiple values' => CONTENT_HANDLE_CORE,
 514     ),
 515     'short' => array(
 516       'label' => t('Short, as link with title "Link"'),
 517       'field types' => array('link'),
 518       'multiple values' => CONTENT_HANDLE_CORE,
 519     ),
 520     'label' => array(
 521       'label' => t('Label, as link with label as title'),
 522       'field types' => array('link'),
 523       'multiple values' => CONTENT_HANDLE_CORE,
 524     ),
 525     'separate' => array(
 526       'label' => t('Separate title and URL'),
 527       'field types' => array('link'),
 528       'multiple values' => CONTENT_HANDLE_CORE,
 529     ),
 530   );
 531 }
 532
 533 /**
 534  * Theme function for 'default' text field formatter.
 535  */
 536 function theme_link_formatter_default($element) {
 537   // Display a normal link if both title and URL are available.
 538   if (!empty($element['#item']['display_title']) && !empty($element['#item']['url'])) {
 539     return l($element['#item']['display_title'], $element['#item']['url'], $element['#item']);
 540   }
 541   // If only a title, display the title.
 542   elseif (!empty($element['#item']['display_title'])) {
 543     return check_plain($element['#item']['display_title']);
 544   }
 545 }
 546
 547 /**
 548  * Theme function for 'plain' text field formatter.
 549  */
 550 function theme_link_formatter_plain($element) {
 551   return empty($element['#item']['url']) ? check_plain($element['#item']['title']) : check_plain($element['#item']['url']);
 552 }
 553
 554 /**
 555  * Theme function for 'url' text field formatter.
 556  */
 557 function theme_link_formatter_url($element) {
 558   return $element['#item']['url'] ? l($element['#item']['display_url'], $element['#item']['url'], $element['#item']) : '';
 559 }
 560
 561 /**
 562  * Theme function for 'short' text field formatter.
 563  */
 564 function theme_link_formatter_short($element) {
 565   return $element['#item']['url'] ? l(t('Link'), $element['#item']['url'], $element['#item']) : '';
 566 }
 567
 568 /**
 569  * Theme function for 'label' text field formatter.
 570  */
 571 function theme_link_formatter_label($element) {
 572   return $element['#item']['url'] ? l($element['#item']['label'], $element['#item']['url'], $element['#item']) : '';
 573 }
 574
 575 /**
 576  * Theme function for 'separate' text field formatter.
 577  */
 578 function theme_link_formatter_separate($element) {
 579   $output = '';
 580   $output .= '<div class="link-item">';
 581   $output .= '<div class="link-title">'. $element['#item']['display_title'] .'</div>';
 582   $output .= '<div class="link-url">'. l($element['#item']['display_url'], $element['#item']['url'], $element['#item']) .'</div>';
 583   $output .= '</div>';
 584   return $output;
 585 }
 586
 587 function link_token_list($type = 'all') {
 588   if ($type == 'field' || $type == 'all') {
 589     $tokens = array();
 590
 591     $tokens['link']['url'] = t("Link URL");
 592     $tokens['link']['title'] = t("Link title");
 593     $tokens['link']['view'] = t("Formatted html link");
 594
 595     return $tokens;
 596   }
 597 }
 598
 599 function link_token_values($type, $object = NULL) {
 600   if ($type == 'field') {
 601     $item = $object[0];
 602
 603     $tokens['url'] = $item['url'];
 604     $tokens['title'] = $item['title'];
 605     $tokens['view'] = $item['view'];
 606
 607     return $tokens;
 608   }
 609 }
 610
 611 /**
 612  * Forms a valid URL if possible from an entered address.
 613  * Trims whitespace and automatically adds an http:// to addresses without a protocol specified
 614  *
 615  * @param string $url
 616  * @param string $protocol The protocol to be prepended to the url if one is not specified
 617  */
 618 function link_cleanup_url($url, $protocol = "http") {
 619   $url = trim($url);
 620   $type = link_validate_url($url);
 621
 622   if ($type == LINK_EXTERNAL) {
 623     // Check if there is no protocol specified.
 624     $protocol_match = preg_match("/^([a-z0-9][a-z0-9\.\-_]*:\/\/)/i",$url);
 625     if (empty($protocol_match)) {
 626       // But should there be? Add an automatic http:// if it starts with a domain name.
 627       $domain_match = preg_match('/^(([a-z0-9]([a-z0-9\-_]*\.)+)('. LINK_DOMAINS .'|[a-z]{2}))/i',$url);
 628       if (!empty($domain_match)) {
 629         $url = $protocol."://".$url;
 630       }
 631     }
 632   }
 633
 634   return $url;
 635 }
 636
 637 /**
 638  * A lenient verification for URLs. Accepts all URLs following RFC 1738 standard
 639  * for URL formation and all email addresses following the RFC 2368 standard for
 640  * mailto address formation.
 641  *
 642  * @param string $text
 643  * @return mixed Returns boolean FALSE if the URL is not valid. On success, returns an object with
 644  * the following attributes: protocol, hostname, ip, and port.
 645  */
 646 function link_validate_url($text) {
 647
 648   $allowed_protocols = variable_get('filter_allowed_protocols', array('http', 'https', 'ftp', 'news', 'nntp', 'telnet', 'mailto', 'irc', 'ssh', 'sftp', 'webcal'));
 649
 650   $protocol = '((' . implode("|", $allowed_protocols) . '):\/\/)';
 651   $authentication = '([a-z0-9]+(:[a-z0-9]+)?@)';
 652   $domain = '((([a-z0-9]([a-z0-9\-_\[\]]*\.))+)('. LINK_DOMAINS .'|[a-z]{2}))';
 653   $ipv4 = '([0-9]{1,3}(\.[0-9]{1,3}){3})';
 654   $ipv6 = '([0-9a-fA-F]{1,4}(\:[0-9a-fA-F]{1,4}){7})';
 655   $port = '(:([0-9]{1,5}))';
 656
 657   // Pattern specific to eternal links.
 658   $external_pattern = '/^' . $protocol . '?'. $authentication . '?' . '(' . $domain . '|' . $ipv4 . '|' . $ipv6 . ' |localhost)' . $port . '?';
 659
 660   // Pattern specific to internal links.
 661   $internal_pattern = "/^([a-z0-9_\-+\[\]]+)";
 662
 663   $directories = "(\/[a-z0-9_\-\.~+%=&,$'():;*@\[\]]*)*";
 664   $query = "(\/?\?([?a-z0-9+_\-\.\/%=&,$'():;*@\[\]]*))";
 665   $anchor = "(#[a-z0-9_\-\.~+%=&,$'():;*@\[\]]*)";
 666
 667   // The rest of the path for a standard URL.
 668   $end = $directories . '?' . $query . '?' .  $anchor . '?' . '$/i';
 669
 670   $user = '[a-zA-Z0-9_\-\.\+\^!#\$%&*+\/\=\?\`\|\{\}~\'\[\]]+';
 671   $email_pattern = '/^mailto:' . $user . '@' . '(' . $domain . '|' . $ipv4 .'|'. $ipv6 . '|localhost)' . $query . '$/';
 672
 673   if (preg_match($external_pattern . $end, $text)) {
 674     return LINK_EXTERNAL;
 675   }
 676   elseif (preg_match($internal_pattern . $end, $text)) {
 677     return LINK_INTERNAL;
 678   }
 679   elseif (in_array('mailto', $allowed_protocols) && preg_match($email_pattern, $text)) {
 680     return LINK_EMAIL;
 681   }
 682   elseif (strpos($text, '<front>') === 0) {
 683     return LINK_FRONT;
 684   }
 685   return FALSE;
 686 }