function _cdn_generate_url_prefix_regex in CDN 6.2

Same name and namespace in other branches

1. 7.2 cdn.fallback.inc \_cdn_generate_url_prefix_regex()

Generate the URL prefix regular expression, that supports all possible types of file URLs: root-relative, protocol-relative and absolute URLs.

3 calls to _cdn_generate_url_prefix_regex()

cdn_html_alter_css_urls in ./cdn.fallback.inc

Alter CSS file URLs in a piece of HTML.

cdn_html_alter_image_urls in ./cdn.fallback.inc

Alter image file URLs in a piece of HTML.

cdn_html_alter_js_urls in ./cdn.fallback.inc

Alter JS file URLs in a piece of HTML.

File

./cdn.fallback.inc, line 98

Fallback when hook_file_url_alter() is not available (i.e. when the core patch is not installed or when not using a patched Drupal distribution): use the Parallel module's logic (with some adaptations to be able to use the CDN module's logic…

Code

function _cdn_generate_url_prefix_regex() {
  global $base_url;
  static $url_prefix_regex;
  if (!isset($url_prefix_regex)) {
    $url_prefixes = array(
      preg_quote(base_path()) . '(?!/)',
      // Root-relative URL.
      // Note:  root-relative URL that isn't a protocol-relative URL. The
      // negative lookahead for a trailing slash is relaly only necessary
      // when this site is installed in the document root (i.e. when the base
      // path equals "/"), because this would otherwise match *all* protocol-
      // relative URLs, also those that already point to the CDN.
      preg_quote('//' . $_SERVER['HTTP_HOST'] . base_path()),
      // Protocol-relative URL.
      preg_quote($base_url . '/'),
    );
    $regexes = array();
    $farfuture = preg_quote('cdn/farfuture/');
    foreach ($url_prefixes as $url_prefix) {
      $regexes[] = $url_prefix . '(?!' . $farfuture . ')';
    }

    // The URL prefix regex that will match all URLs to the current site,
    // except for those that already point to Far Future expiration URLs.
    $url_prefix_regex = implode('|', $regexes);
  }
  return $url_prefix_regex;
}