original_string: protected function resolveCssRelatives($css, $base = '')
      {
          if (!($css = (string) $css)) {
              return $css; // Nothing to do.
          }
          $this->current_base = $base; // Make this available to callback handlers (possible empty string here).
  
          $import_without_url_regex = '/(?P<import>@(?:\-(?:'.$this->regex_vendor_css_prefixes.')\-)?import\s*)(?P<open_encap>["\'])(?P<url>.+?)(?P<close_encap>\\2)/ui';
          $any_url_regex            = '/(?P<url_>url\s*)(?P<open_bracket>\(\s*)(?P<open_encap>["\']?)(?P<url>.+?)(?P<close_encap>\\3)(?P<close_bracket>\s*\))/ui';
  
          $css = preg_replace_callback($import_without_url_regex, [$this, 'resolveCssRelativesImportCb'], $css);
          $css = preg_replace_callback($any_url_regex, [$this, 'resolveCssRelativesUrlCb'], $css);
  
          return $css;
      }
code: protected function resolveCssRelatives($css, $base = '')
      {
          if (!($css = (string) $css)) {
              return $css; // Nothing to do.
          }
          $this->current_base = $base; // Make this available to callback handlers (possible empty string here).
  
          $import_without_url_regex = '/(?P<import>@(?:\-(?:'.$this->regex_vendor_css_prefixes.')\-)?import\s*)(?P<open_encap>["\'])(?P<url>.+?)(?P<close_encap>\\2)/ui';
          $any_url_regex            = '/(?P<url_>url\s*)(?P<open_bracket>\(\s*)(?P<open_encap>["\']?)(?P<url>.+?)(?P<close_encap>\\3)(?P<close_bracket>\s*\))/ui';
  
          $css = preg_replace_callback($import_without_url_regex, [$this, 'resolveCssRelativesImportCb'], $css);
          $css = preg_replace_callback($any_url_regex, [$this, 'resolveCssRelativesUrlCb'], $css);
  
          return $css;
      }
code_tokens: protected function resolveCssRelatives ( $ css , $ base = '' ) { if ( ! ( $ css = ( string ) $ css ) ) { return $ css ; // Nothing to do. } $ this -> current_base = $ base ; // Make this available to callback handlers (possible empty string here). $ import_without_url_regex = '/(?P<import>@(?:\-(?:' . $ this -> regex_vendor_css_prefixes . ')\-)?import\s*)(?P<open_encap>["\'])(?P<url>.+?)(?P<close_encap>\\2)/ui' ; $ any_url_regex = '/(?P<url_>url\s*)(?P<open_bracket>\(\s*)(?P<open_encap>["\']?)(?P<url>.+?)(?P<close_encap>\\3)(?P<close_bracket>\s*\))/ui' ; $ css = preg_replace_callback ( $ import_without_url_regex , [ $ this , 'resolveCssRelativesImportCb' ] , $ css ) ; $ css = preg_replace_callback ( $ any_url_regex , [ $ this , 'resolveCssRelativesUrlCb' ] , $ css ) ; return $ css ; }
docstring: Resolve relative URLs in CSS code.
  
  @since 140417 Initial release.
  
  @param string $css  CSS code.
  @param string $base Optional. Base URL to calculate from.
  Defaults to the current HTTP location for the browser.
  
  @return string CSS code after having all URLs resolved.
docstring_tokens: Resolve relative URLs in CSS code .