accessibletargetblankfilter.module

<?php
/**
 * @file
 * Provides the ability for a link tags with target="_blank" to be 
 * automatically converted to a more accessible format, by alerting users via 
 * the use of text that the link will open in a new window.
 *
 * The text to be displayed can be changed via the filter settings form
 */

function accessibletargetblankfilter_init() {
    
    drupal_add_css(drupal_get_path('module', 'accessibletargetblankfilter') . '/accessibletargetblankfilter.css');
    drupal_add_js(drupal_get_path('module', 'accessibletargetblankfilter') . '/accessibletargetblankfilter.js', 'module', 'header', TRUE);
    
}

function accessibletargetblank_getDefaultText() {
    return 'This link will open in a new window';
}

/**
 * Implementation of hook_filter_tips().
 */
function accessibletargetblankfilter_filter_tips($delta, $format, $long = FALSE) {
  $textToAdd = variable_get('accessibletargetblankfilter_texttoadd', accessibletargetblank_getDefaultText());
  
  if ($long) {
    return t('Text to be added to the link tag to denote that it will open in a new window. The current text is ' . $textToAdd);
  }
  else {
    return t('Text to be added to the link tag to denote that it will open in a new window. The current text is ' . $textToAdd);
  }
}

/**
 * Implementation of hook_filter().
 */
function accessibletargetblankfilter_filter($op, $delta = 0, $format = -1, $text = '') {
  
    switch ($op) {
    case 'list':
      return array(0 => t('Accessible Target Blank Filter'));

    case 'description':
      $textToAdd = variable_get('accessibletargetblankfilter_texttoadd', accessibletargetblank_getDefaultText());
      return t('Text to be added to the link tag to denote that it will open in a new window. The current text is ' . $textToAdd);

    case 'settings':
      return _accessibletargetblankfilter_settings();

    case 'process':
      $textToAdd = variable_get('accessibletargetblankfilter_texttoadd', accessibletargetblank_getDefaultText());
      $pattern = '~<a\s++[^>]*?\btarget\s*+=\s*+([\'"])_blank\1[^>]*+>\K((?:[^<]++|<++(?!/a>))*+)~is';
      $text = preg_replace($pattern, "$2<span class=\"linkTargetBlank\">" . $textToAdd . "</span>", $text);
      
      return $text;

    default:
      return $text;
  }
}

/**
 * Processes highlight by adding span tag.
 */
/*
function accessibletargetblankfilter_process($text) {
  $textToAdd = variable_get('accessibletargetblankfilter_texttoadd', accessibletargetblank_getDefaultText());
  return '<span class="linkTargetBlankParent">' . $text . ' </span><span class="linkTargetBlank">(' . $textToAdd . ')</span>';
}
 */

/**
 * The settings form for this filter. Default text is set as
 * "This link will open in a new window"
 * 
 */
function _accessibletargetblankfilter_settings() {
  $form['accessibletargetblankfilter'] = array(
    '#type' => 'fieldset',
    '#title' => t('Accessible Target Blank Filter'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );
  $form['accessibletargetblankfilter']['accessibletargetblankfilter_texttoadd'] = array(
    '#title' => t('Text to Add'),
    '#description' => t('Text to be added to the link tag to denote that it will open in a new window'),
    '#type' => 'textfield',
    '#required' => TRUE,
    '#default_value' => variable_get('accessibletargetblankfilter_texttoadd', accessibletargetblank_getDefaultText()),
  );
  
  return $form;
}