cdn.basic.css.inc in CDN 6.2

Overrides of Drupal's CSS aggregation system. Ensures that files referenced by CSS files are also served from the CDN, according to the CDN module's CSS aggregation rules.

File

cdn.basic.css.inc

<?php

/**
 * @file
 * Overrides of Drupal's CSS aggregation system. Ensures that files referenced
 * by CSS files are also served from the CDN, according to the CDN module's
 * CSS aggregation rules.
 */

/**
 * Mostly based on drupal_get_css().
 */
function _cdn_css_aggregate(&$vars) {

  // Don't override Drupal core's aggregation if this page is not going to use
  // a CDN anyway.
  if (!cdn_check_protocol() && !cdn_check_drupal_path($_GET['q'])) {
    return;
  }
  $output = '';
  $prefix = $suffix = '<!-- CSS aggregated by CDN module. -->' . "\n";
  $css = $vars['css'];
  $no_module_preprocess = '';
  $no_theme_preprocess = '';

  // Create different CSS aggregation files for HTTP and HTTPS.
  $schema = cdn_request_is_https() ? 'https' : 'http';
  $query_string = variable_get('css_js_query_string', '0');
  $preprocess_css = variable_get('preprocess_css', FALSE) && (!defined('MAINTENANCE_MODE') || MAINTENANCE_MODE != 'update');
  $directory = file_directory_path();
  $is_writable = is_dir($directory) && is_writable($directory) && variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PUBLIC;
  foreach ($css as $media => $types) {

    // If CSS preprocessing is off, we still need to output the styles.
    // Additionally, go through any remaining styles if CSS preprocessing is on and output the non-cached ones.
    foreach ($types as $type => $files) {
      if ($type == 'module') {

        // Setup theme overrides for module styles.
        $theme_styles = array();
        foreach (array_keys($css[$media]['theme']) as $theme_style) {
          $theme_styles[] = basename($theme_style);
        }
      }
      foreach ($types[$type] as $file => $preprocess) {

        // If the theme supplies its own style using the name of the module style, skip its inclusion.
        // This includes any RTL styles associated with its main LTR counterpart.
        if ($type == 'module' && in_array(str_replace('-rtl.css', '.css', basename($file)), $theme_styles)) {

          // Unset the file to prevent its inclusion when CSS aggregation is enabled.
          unset($types[$type][$file]);
          continue;
        }

        // Only include the stylesheet if it exists.
        if (file_exists($file)) {
          if (!$preprocess || !($is_writable && $preprocess_css)) {

            // Also build CSS cache files for other files; so that the file
            // URLs in them are altered to point to the CDN.
            $fake_types = array(
              $type => array(
                $file => TRUE,
              ),
            );
            $filename = 'cdn_css_' . $schema . '_' . md5(serialize($types) . $query_string . 'cdn' . $file) . '_' . basename($file);
            $file = _cdn_build_css_cache($fake_types, $filename);

            // If a CSS file is not to be preprocessed and it's a module CSS file, it needs to *always* appear at the *top*,
            // regardless of whether preprocessing is on or off.
            if (!$preprocess && $type == 'module') {
              $no_module_preprocess .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . _cdn_css_file_create_url($file) . '" />' . "\n";
            }
            elseif (!$preprocess && $type == 'theme') {
              $no_theme_preprocess .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . _cdn_css_file_create_url($file) . '" />' . "\n";
            }
            else {
              $output .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . _cdn_css_file_create_url($file) . '" />' . "\n";
            }
          }
        }
      }
    }
    if ($is_writable && $preprocess_css) {

      // Prefix filename to prevent blocking by firewalls which reject files
      // starting with "ad*".
      $filename = 'cdn_css_' . $schema . '_' . md5(serialize($types) . $query_string . 'cdn') . '.css';
      $preprocess_file = _cdn_build_css_cache($types, $filename);
      $output .= '<link type="text/css" rel="stylesheet" media="' . $media . '" href="' . _cdn_css_file_create_url($preprocess_file) . '" />' . "\n";
    }
  }
  $vars['styles'] = $prefix . $no_module_preprocess . $output . $no_theme_preprocess . $suffix;
}
function _cdn_build_css_cache($types, $filename) {
  $data = '';

  // Create the css/ within the files folder.
  $csspath = file_create_path('css');
  file_check_directory($csspath, FILE_CREATE_DIRECTORY);
  if (!file_exists($csspath . '/' . $filename)) {

    // Build aggregate CSS file.
    foreach ($types as $type) {
      foreach ($type as $file => $cache) {
        if ($cache) {
          $contents = drupal_load_stylesheet($file, TRUE);

          // Return the Drupal path to where this CSS file originated from.
          $base = dirname($file) . '/';
          _cdn_build_css_path(NULL, $base);

          // Prefix all paths within this CSS file, ignoring external and absolute paths.
          $data .= preg_replace_callback('/url\\([\'"]?(?![a-z]+:|\\/+)([^\'")]+)[\'"]?\\)/i', '_cdn_build_css_path', $contents);
        }
      }
    }

    // Per the W3C specification at http://www.w3.org/TR/REC-CSS2/cascade.html#at-import,
    // @import rules must proceed any other style, so we move those to the top.
    $regexp = '/@import[^;]+;/i';
    preg_match_all($regexp, $data, $matches);
    $data = preg_replace($regexp, '', $data);
    $data = implode('', $matches[0]) . $data;

    // Create the CSS file.
    file_save_data($data, $csspath . '/' . $filename, FILE_EXISTS_REPLACE);
  }
  return $csspath . '/' . $filename;
}
function _cdn_build_css_path($matches, $base = NULL) {
  static $_base;

  // Store base path for preg_replace_callback.
  if (isset($base)) {
    $_base = $base;
  }

  // Prefix with base and remove '../' segments where possible.
  $path = $_base . $matches[1];
  $last = '';
  while ($path != $last) {
    $last = $path;
    $path = preg_replace('`(^|/)(?!\\.\\./)([^/]+)/\\.\\./`', '$1', $path);
  }
  return 'url(' . _cdn_css_file_create_url($path) . ')';
}

/**
 * Generate CDN file URL without file_create_url() if the core patch has not
 * been applied.
 */
function _cdn_css_file_create_url($path) {
  if (variable_get(CDN_THEME_LAYER_FALLBACK_VARIABLE, FALSE) == TRUE) {

    // Store the current path as the old path, then let cdn_file_url_alter()
    // do its magic by invoking all file_url_alter hooks. When the path hasn't
    // changed and is not already root-relative or protocol-relative, then
    // generate a file URL as Drupal core would: prepend the base path.
    $old_path = $path;
    drupal_alter('file_url', $path);
    if ($path == $old_path && drupal_substr($path, 0, 1) != '/' && drupal_substr($path, 0, 2) != '//') {
      $path = base_path() . $path;
    }
    return $path;
  }
  else {
    return file_create_url($path);
  }
}

Functions

Name	Description
_cdn_build_css_cache
_cdn_build_css_path
_cdn_css_aggregate	Mostly based on drupal_get_css().
_cdn_css_file_create_url	Generate CDN file URL without file_create_url() if the core patch has not been applied.