1 theme.inc theme_get_suggestions($args, $base, $delimiter = '__')

Generate an array of suggestions from path arguments.

This is typically called for adding to the 'theme_hook_suggestions' or 'classes' variables from within preprocess functions, when wanting to base the additional suggestions on the path of the current page.


$args: An array of path arguments, such as from function arg().

$base: A string identifying the base 'thing' from which more specific suggestions are derived. For example, 'page' or 'html'.

$delimiter: The string used to delimit increasingly specific information. The default of '__' is appropriate for theme hook suggestions. '-' is appropriate for extra classes.

Return value

An array of suggestions, suitable for adding to: $variables['theme_hook_suggestions'] within a preprocess function or to $variables['classes'] if the suggestions represent extra CSS classes.


core/includes/theme.inc, line 2846
The theme system, which controls the output of Backdrop.


function theme_get_suggestions($args, $base, $delimiter = '__') {

  // Build a list of suggested theme hooks or body classes in order of
  // specificity. One suggestion is made for every element of the current path,
  // though numeric elements are not carried to subsequent suggestions. For
  // example, for $base='page', http://www.example.com/node/1/edit would result
  // in the following suggestions and body classes:
  // page__node              page-node
  // page__node__%           page-node-%
  // page__node__1           page-node-1
  // page__node__edit        page-node-edit

  $suggestions = array();
  $prefix = $base;
  foreach ($args as $arg) {
    // Remove slashes or null per SA-CORE-2009-003 and change - (hyphen) to _
    // (underscore).
    // When we discover templates in @see backdrop_find_theme_templates,
    // hyphens (-) are converted to underscores (_) before the theme hook
    // is registered. We do this because the hyphens used for delimiters
    // in hook suggestions cannot be used in the function names of the
    // associated preprocess functions. Any page templates designed to be used
    // on paths that contain a hyphen are also registered with these hyphens
    // converted to underscores so here we must convert any hyphens in path
    // arguments to underscores here before fetching theme hook suggestions
    // to ensure the templates are appropriately recognized.
    $arg = str_replace(array("/", "\\", "\0", '-'), array('', '', '', '_'), $arg);
    // The percent acts as a wildcard for numeric arguments since
    // asterisks are not valid filename characters on many filesystems.
    if (is_numeric($arg)) {
      $suggestions[] = $prefix . $delimiter . '%';
    $suggestions[] = $prefix . $delimiter . $arg;
    if (!is_numeric($arg)) {
      $prefix .= $delimiter . $arg;
  if (backdrop_is_front_page()) {
    // Front templates should be based on root only, not prefixed arguments.
    $suggestions[] = $base . $delimiter . 'front';

  return $suggestions;