pagedown.module

<?php
/**
 * Implementation of hook_perm().
 */
function pagedown_perm() {
  return array('access pagedown');
}

/**
 * Implementation of hook_filter().
 */
function pagedown_filter($op, $delta = 0, $format = -1, $text = '', $cache_id = 0) {
  switch ($op) {
    case 'list':
      return array(0 => t('Pagedown'));

    case 'description':
      return t('Allows users to post using the Pagedown editor with Markdown');

    case 'process':
      require_once('markdown.php');
      $html = Markdown($text);
      return $html;

    default:
      return $text;
  }
}

/**
 * Implementation of hook_filter_tips().
 */
function pagedown_filter_tips($delta, $format, $long = FALSE) {
  // TODO: add tips
  return t('Pagedown tips coming soon.');
}

/**
 * Implementation of hook_elements
 */
function pagedown_elements() {
  $type = array();
  if (user_access('access pagedown')) {
    // Let Pagedown potentially process each textarea.
    $type['textarea'] = array('#process' => array('pagedown_process_textarea'));
  }

  return $type;
}

/**
 * Initialization for Pagedown javascript/css.
 */
function pagedown_asset_init() {
  static $pd_init = false;

  if(!$pd_init) {
    $pd_init = true;

    $mod_path = drupal_get_path('module', 'pagedown');
    drupal_add_css($mod_path . '/pagedown.css', 'module', 'all', FALSE);
    drupal_add_js($mod_path . '/js/Markdown.Converter.js');
    drupal_add_js($mod_path . '/js/Markdown.Editor.js');
    drupal_add_js($mod_path . '/js/Markdown.Sanitizer.js');
  }
}

/**
 * Process a textarea for use with Pagedown
 */
function pagedown_process_textarea($element) {
  pagedown_asset_init();

  // check if we are acting on this element
  $targets = pagedown_get_targets();
  if(!in_array($element['#id'], $targets)) return $element;

  $selector = $element['#id'];
  $pagedown_element_init = <<<EOD
  (function () {
      $(function() {

        var bar = $('<div/>').attr('id', '$selector-bar');
        var preview_wrap = $('<div/>').attr('id', '$selector-preview-wrap').addClass('wmd-preview-wrap');
        var preview = $('<div/>').attr('id', '$selector-preview').addClass('wmd-preview');

        preview.appendTo(preview_wrap);

        $('#$selector').before(bar);
        $('#$selector-wrapper').after(preview_wrap);

        var textarea_converter = new Markdown.Converter();
        var help = function () { alert("Not yet implemented"); }

        var editor = new Markdown.Editor(textarea_converter, "{$element['#id']}", { handler: help });
        editor.run();

      });
  })();
EOD;

  drupal_add_js($pagedown_element_init, 'inline');
  return $element;
}

/**
 * TODO: this should collect individual values from the database. currently the form element targets are
 * stored in a single variable. eventually, controls to enable this per-textarea should be added
 */
function pagedown_get_targets() {
  static $targets = array();
  static $checked = false;

  if(!$checked) {
    $checked = true;

    // TODO: again, this should collect from db rather than a single variable
    $targets = variable_get('pagedown_elements', array());
  }

  return $targets;
}