drupdown.module

<?php
/**
 * @file
 * Main drupdown implementation file.
 */

// TODO: Fix nesting elements in links.
$nb = str_repeat('(?>[^\[\]]+|\[', 6) . str_repeat('\])*', 6);
$np = str_repeat('(?>[^()\s]+|\(', 4) . str_repeat('(?>\)))*', 4);
$nb = ".*";
$np = ".*";

define('DRUPDOWN_LINK_REGEX', implode('', array(
  '\[(?<alt>' . $nb . '?)\]',
  '(',
    '(\(',
      '(?<url>' . $np . '?)',
      '(',
        '\s?',
        '\"(?<title>' . $np . '?)\"',
      ')?',
    '\))',
    '|',
    '(\[(?<ref>' . $np . '?)\])',
  ')(\{.*?\})?',
)));

module_load_include('inc', 'drupdown', 'includes/drupdown.ui');
module_load_include('inc', 'drupdown', 'includes/drupdown.patterns');

/**
 * Implements hook_menu().
 */
function drupdown_menu() {
  return array(
    'drupdown/playground' => array(
      'title' => 'Drupdown Playground',
      'page callback' => 'drupal_get_form',
      'page arguments' => array('drupdown_playground'),
      'access callback' => TRUE,
      'file' => 'includes/drupdown.pages.inc',
      'type' => MENU_CALLBACK,
    ),
    'drupdown/ajax-embed' => array(
      'title' => 'Drupdown Ajax Callback',
      'page callback' => 'drupdown_ajax',
      'access callback' => TRUE,
      'type' => MENU_CALLBACK,
    ),
    'admin/config/content/drupdown' => array(
      'title' => 'Drupdown',
      'description' => 'Configure drupdown basics.',
      'page callback' => 'drupal_get_form',
      'page arguments' => array('drupdown_settings_form'),
      'file' => 'includes/drupdown.pages.inc',
      'access arguments' => array('administer site configuration'),
    ),
  );
}

/**
 * Ajax callback to deliver inline html for embeddables.
 */
function drupdown_ajax() {
  $info['url'] = $_GET['url'];
  drupdown_match_pattern($info);
  $doc = str_get_html($info['content']);
  $fixed_elements = $doc->find('[width]');
  foreach ($fixed_elements as $elem) {
    $width = intval($elem->width);
    $height = intval($elem->height);
    unset($elem->width);
    unset($elem->height);
    $elem->{'data-aspect-ratio'} = $width / $height;
  }
  print $doc->save();
}

/**
 * Implements hook_init().
 */
function drupdown_init() {
  /*
  if (module_exists('colorbox') && _colorbox_active()) {
    drupal_add_js(drupal_get_path('module', 'drupdown') . '/js/drupdown-colorbox.js');
  }
  */
  drupal_add_js(drupal_get_path('module', 'drupdown') . '/js/drupdown-ratio.js');
  drupal_add_css(drupal_get_path('module', 'drupdown') . '/css/drupdown.theme.css');
  drupal_add_css(drupal_get_path('module', 'drupdown') . '/css/drupdown.admin.css');
  $zeropath = libraries_get_path('ZeroClipboard');
  $settings = array();
  if (file_exists($zeropath . '/ZeroClipboard.js')) {
    $settings['ZeroClipboardPath'] = file_create_url($zeropath . '/ZeroClipboard.swf');
  }
  if (module_exists('codemirror')) {
    $embeds = variable_get('drupdown_codemirror_embeds', array());
    $languages = codemirror_languages();
    $aliases = array();
    foreach ($embeds as $mime) {
      if ($mime) {
        $aliases[$languages[$mime]['mode']] = $mime;
      }
    }
    $settings['codemirror'] = $aliases;
  }
  drupal_add_js(array('drupdown' => $settings), 'setting');
}

/**
 * Implements hook_filter_info().
 */
function drupdown_filter_info() {
  $filters['filter_drupdown_pre'] = array(
    'title' => t('Drupdown Pre'),
    'description' => t('Preprocess Markdown.'),
    'process callback' => '_filter_drupdown_pre',
    'default settings' => array('styles' => array()),
  );
  $filters['filter_drupdown_markdown'] = array(
    'title' => t('Drupdown Markdown'),
    'description' => t('Process Markdown.'),
    'process callback' => '_filter_drupdown_markdown',
    'default settings' => array('styles' => array()),
  );
  $filters['filter_drupdown_post'] = array(
    'title' => t('Drupdown Post'),
    'description' => t('Postprocess Markdown.'),
    'process callback' => '_filter_drupdown_post',
    'default settings' => array('styles' => array()),
  );
  return $filters;
}

/**
 * Implements hook_theme().
 */
function drupdown_theme() {
  $path = drupal_get_path('module', 'drupdown') . '/templates';
  return array(
    'drupdown_figure' => array(
      'variables' => array(
        'content' => FALSE,
        'caption' => FALSE,
        'types' => array(),
        'domid' => FALSE,
        'classes' => array(),
      ),
      'path' => $path,
      'template' => 'drupdown-figure',
    ),
    'drupdown_figure_group' => array(
      'variables' => array(
        'figures' => array(),
      ),
      'path' => $path,
      'template' => 'drupdown-figure-group',
    ),
    'drupdown_link_embed' => array(
      'variables' => array(
        'title' => '',
        'image' => FALSE,
        'description' => FALSE,
        'url' => FALSE,
        'domain' => FALSE,
      ),
      'path' => $path,
      'template' => 'drupdown-link-embed',
    ),
  );
}

/**
 * Implements template_preprocess_HOOK().
 */
function template_preprocess_drupdown_figure(&$variables) {
  foreach ($variables['classes'] as $class) {
    $variables['classes_array'][] = $class;
  }
  foreach ($variables['types'] as $type) {
    $variables['classes_array'][] = 'drupdown-' . $type;
  }
  if (empty($variables['caption'])) {
    $variables['classes_array'][] = 'drupdown-nocaption';
  }
}

/**
 * Parse markdown.
 */
function _filter_drupdown_markdown($text, $format) {
  require_once libraries_get_path('php-markdown') . '/markdown.php';
  return Markdown($text);
}

/**
 * Drupdown pre filter.
 */
function _filter_drupdown_pre($text, $format) {
  // Append newline. Safety first!
  $text .= "\n";
  // Search for language islands.
  $text = preg_replace('/\[(.+?)\]\(([a-z]+)\)/', '<span lang="$2">$1</span>', $text);

  // Newlines are also added if line ends with ., :, ;, ! or ?.
  $text = preg_replace('/(?=(\s+)|[.:;!?])\n/', "  \n", $text);

  // If there is a level 1 headline, increase all headlines levels.
  if (preg_match("/^#\s*[^#]/m", $text) || preg_match("/[^\n]+\n===+\n/m", $text)) {
    $text = preg_replace("/^#+/m", "$0#", $text);
    $text = preg_replace("/^([^\s]*)\n(---+)/m", "### $1", $text);
    $text = preg_replace("/^([^\s]*)\n(===+)/m", "$1\n---", $text);
  }

  // Switch ``` fenced code blocks syntax to ~~~.
  $text = preg_replace_callback('/^[`|~]{3,}\h*(.*)?/m', '_drupdown_fenced_codeblocks', $text);

  // Automatically add newlines before and after something that looks like
  // a list.
  $text = preg_replace('/^(\s*(\d+\.|\+|\*|\-).*\\n){2,}/xm', "\n$0\n", $text);

  // Streamline links. Embeds will be added automatically based on their line
  // position.
  $text = preg_replace('/\!\[/', '[', $text);

  // Search for embeds and group them.
  $grouping_regex = '/(\n|^)((' . DRUPDOWN_LINK_REGEX . ' *)\n)+/';
  $text = preg_replace_callback($grouping_regex, '_drupdown_group_embeds', $text);
  return $text;
}

/**
 * Process codeblock delimiters like ``` or ~~~.
 */
function _drupdown_fenced_codeblocks($matches) {
  return '~~~ ' . str_replace('/', '__', str_replace('-', '_', $matches[1]));
}

/**
 * Callback for embed grouping.
 */
function _drupdown_group_embeds($matches) {
  $links = explode("\n", trim($matches[0]));
  $figures = array();
  $grouping = TRUE;
  array_walk($links, 'trim');
  foreach ($links as $link) {
    $info = array(
      'url' => preg_replace('/.*?((_||[a-z])+\:\/\/[^ |\)]+).*/', '$1', $link, 1),
      'alt' => '',
      'title' => '',
    );
    drupdown_match_pattern($info);
    if ($info['figure']) {
      $grouping = TRUE && $grouping;
      $figures[] = '<div class="drupdown-figure" markdown="1">' . $link . '</div>';
    }
    else {
      $grouping = FALSE;
      $figures[] = $link;
    }
  }
  if (count($figures) > 1 && $grouping) {
    return "\n" . theme('drupdown_figure_group', array('figures' => $figures)) . "\n\n";
  }
  else {
    return "\n" . implode('', $figures) . "  \n";
  }
}

/**
 * Drupdown post filter.
 */
function _filter_drupdown_post($text, $format) {
  $doc = new simple_html_dom();
  $doc->load($text);

  // Process figure embeds.
  $figures = $doc->find('.drupdown-figure');
  foreach ($figures as $figure) {
    $link = $figure->find('a', 0);
    if (!$link) {
      continue;
    }
    $info = array(
      'url' => $link->href,
      'alt' => $link->innertext,
      'title' => $link->title,
    );
    if (drupdown_match_pattern($info) && array_key_exists('content', $info)) {
      if (!in_array('link', $info['types'])) {
        $theme_hook = array('drupdown_figure');
        foreach ($info['types'] as $type) {
          $theme_hook[] = $type;
        }
        $content = theme(implode('__', $theme_hook), array(
          'content' => $info['content'],
          'caption' => $info['title'],
          'types' => $info['types'],
          'domid' => $link->id,
          'classes' => explode(' ', $link->class),
        ));
        $figure->outertext = $content;
      }
    }
    else {
      $figure->innertext = '<p class="drupdown-broken-link">' . $link->innertext . '</p>';
    }
  }

  $doc = str_get_html($doc->save());

  $links = $doc->find('a');
  foreach ($links as $link) {
    if ($link->rel == 'footnote' || $link->rev == 'footnote' || preg_match('/drupdown\-processed/', $link->class)) {
      continue;
    }
    $info = array(
      'url' => $link->href,
      'alt' => $link->innertext,
      'title' => $link->title,
    );
    if (drupdown_match_pattern($info)) {
      if (!$link->title) {
        $link->title = $info['title'];
      }
      $classes = array($link->class, 'drupdown-inline');
      if (!$link->title) {
        $classes[] = 'drupdown-no-title';
      }
      foreach ($info['types'] as $type) {
        $classes[] = 'drupdown-' . $type;
      }
      $link->class = trim(implode(' ', $classes));
      $link->href = $info['url'];
    }
    else {
      $link->outertext = '<span class="drupdown-broken-link">' . $link->innertext . '</span>';
    }
  }

  // Replace with javascript.
  $fixed_elements = $doc->find('[width]');
  foreach ($fixed_elements as $elem) {
    $width = intval($elem->width);
    $height = intval($elem->height);
    unset($elem->width);
    unset($elem->height);
    $elem->{'data-aspect-ratio'} = $width / $height;
  }

  // Process codeblocks.
  $codeblocks = $doc->find('code');
  foreach ($codeblocks as $code) {
    $mime = str_replace('_', '-', str_replace('__', '/', $code->class));
    if (strlen($mime) > 0) {
      $code->outertext = '<code data-mime="' . $mime . '" class="' . $code->class . '">' . $code->innertext . '</code>';
    }
  }
  $text = $doc->save();
  $doc->clear();
  return $text;
}

/**
 * Implements hook_codemirror_languages_alter().
 */
function drupdown_codemirror_languages_alter(&$languages) {
  $mod = file_create_url(drupal_get_path('module', 'drupdown') . '/codemirror');
  $languages['text/x-drupdown'] = array(
    'uri' => $mod . '/drupdown.js',
    'mode' => 'drupdown',
    'name' => t('Drupdown'),
    'js' => array(
      file_create_url($mod . '/drupdown.commands.js'),
    ),
    'css' => array(),
  );
}