function _theme_process_registry

Process a single implementation of hook_theme().

Parameters

$cache: The theme registry that will eventually be cached; It is an associative array keyed by theme hooks, whose values are associative arrays describing the hook:

• 'type': The passed-in $type.
• 'theme path': The passed-in $path.
• 'function': The name of the function generating output for this theme hook. Either defined explicitly in hook_theme() or, if neither 'function' nor 'template' is defined, then the default theme function name is used. The default theme function name is the theme hook prefixed by either 'theme_' for modules or '$name_' for everything else. If 'function' is defined, 'template' is not used.
• 'template': The filename of the template generating output for this theme hook. The template is in the directory defined by the 'path' key of hook_theme() or defaults to $path.
• 'variables': The variables for this theme hook as defined in hook_theme(). If there is more than one implementation and 'variables' is not specified in a later one, then the previous definition is kept.
• 'render element': The renderable element for this theme hook as defined in hook_theme(). If there is more than one implementation and 'render element' is not specified in a later one, then the previous definition is kept.
• 'preprocess functions': See theme() for detailed documentation.

$name: The name of the module, theme engine, base theme engine, theme or base theme implementing hook_theme().

$type: One of 'module', 'theme_engine', 'base_theme_engine', 'theme', or 'base_theme'. Unlike regular hooks that can only be implemented by modules, each of these can implement hook_theme(). _theme_process_registry() is called in aforementioned order and new entries override older ones. For example, if a theme hook is both defined by a module and a theme, then the definition in the theme will be used.

$theme: The loaded $theme object as returned from list_themes().

$path: The directory where $name is. For example, modules/system or themes/bartik.

See also

theme()

_theme_build_registry()

hook_theme()

list_themes()

File

core/includes/theme.inc, line 544

The theme system, which controls the output of Backdrop.

Code

function _theme_process_registry(&$cache, $name, $type, $theme, $path) {
  $result = array();

  $hook_defaults = array(
    'variables' => TRUE,
    'render element' => TRUE,
    'pattern' => TRUE,
    'base hook' => TRUE,
  );

  // Invoke the hook_theme() implementation, process what is returned, and
  // merge it into $cache.
  $function = $name . '_theme';
  if (function_exists($function)) {
    $result = $function($cache, $type, $theme, $path);
    foreach ($result as $hook => $info) {
      // When a theme or engine overrides a module's theme function
      // $result[$hook] will only contain key/value pairs for information being
      // overridden.  Pull the rest of the information from what was defined by
      // an earlier hook.

      // Fill in the type and path of the module, theme, or engine that
      // implements this theme function.
      $result[$hook]['type'] = $type;
      $result[$hook]['theme path'] = $path;

      // If function and file are omitted, default to standard naming
      // conventions.
      if (!isset($info['template']) && !isset($info['function'])) {
        $result[$hook]['function'] = ($type == 'module' ? 'theme_' : $name . '_') . $hook;
      }

      if (isset($cache[$hook]['includes'])) {
        $result[$hook]['includes'] = $cache[$hook]['includes'];
      }

      // If the theme implementation defines a file, then also use the path
      // that it defined. Otherwise use the default path. This allows
      // system.module to declare theme functions on behalf of core .include
      // files.
      if (isset($info['file'])) {
        $include_file = isset($info['path']) ? $info['path'] : $path;
        $include_file .= '/' . $info['file'];
        include_once BACKDROP_ROOT . '/' . $include_file;
        $result[$hook]['includes'][] = $include_file;
      }

      // If the default keys are not set, use the default values registered
      // by the module.
      if (isset($cache[$hook])) {
        $result[$hook] += array_intersect_key($cache[$hook], $hook_defaults);
      }

      // The following apply only to theme hooks implemented as templates.
      if (isset($info['template'])) {
        // Prepend the current theme path when none is set.
        if (!isset($info['path'])) {
          $result[$hook]['template'] = $path . '/' . $info['template'];
        }
      }

      // Allow variable preprocessors for all theme hooks, whether the hook is
      // implemented as a template or as a function.
      // Check for existing variable preprocessors and ensure they're in the
      // expected format.
      if (!isset($info['preprocess functions']) || !is_array($info['preprocess functions'])) {
        $info['preprocess functions'] = array();
        $prefixes = array();

        if ($type == 'module') {
          // Default variable preprocessor prefix.
          $prefixes[] = 'template';
          // Add all modules so they can intervene with their own variable
          // preprocessors. This allows them to provide variable preprocessors
          // even if they are not the owner of the current hook.
          $prefixes += module_list();
        }
        elseif ($type == 'theme_engine' || $type == 'base_theme_engine') {
          // Theme engines get an extra set that come before the normally
          // named variable preprocessors.
          $prefixes[] = $name . '_engine';
          // The theme engine registers on behalf of the theme using the
          // theme's name.
          $prefixes[] = $theme;
        }
        else {
          // This applies when the theme manually registers their own variable
          // preprocessors.
          $prefixes[] = $name;
        }

        foreach ($prefixes as $prefix) {
          // Only use non-hook-specific variable preprocessors for theme hooks
          // implemented as templates. See theme().
          if (isset($info['template']) && function_exists($prefix . '_preprocess')) {
            $info['preprocess functions'][] = $prefix . '_preprocess';
          }
          if (function_exists($prefix . '_preprocess_' . $hook)) {
            $info['preprocess functions'][] = $prefix . '_preprocess_' . $hook;
          }
        }
      }
      // Check for the override flag and prevent the cached variable
      // preprocessors from being used. This allows themes or theme engines to
      // remove variable preprocessors set earlier in the registry build.
      if (!empty($info['override preprocess functions'])) {
        // Flag not needed inside the registry.
        unset($result[$hook]['override preprocess functions']);
      }
      elseif (isset($cache[$hook]['preprocess functions']) && is_array($cache[$hook]['preprocess functions'])) {
        $info['preprocess functions'] = array_merge($cache[$hook]['preprocess functions'], $info['preprocess functions']);
      }
      $result[$hook]['preprocess functions'] = $info['preprocess functions'];
    }

    // Merge the newly created theme hooks into the existing cache.
    $cache = $result + $cache;
  }

  // Let themes have variable preprocessors even if they didn't register a
  // template.
  if ($type == 'theme' || $type == 'base_theme') {
    foreach ($cache as $hook => $info) {
      // Check only if not registered by the theme or engine.
      if (empty($result[$hook])) {
        if (!isset($info['preprocess functions'])) {
          $cache[$hook]['preprocess functions'] = array();
        }
        // Only use non-hook-specific variable preprocessors for theme hooks
        // implemented as templates. See theme().
        if (isset($info['template']) && function_exists($name . '_preprocess')) {
          $cache[$hook]['preprocess functions'][] = $name . '_preprocess';
        }
        if (function_exists($name . '_preprocess_' . $hook)) {
          $cache[$hook]['preprocess functions'][] = $name . '_preprocess_' . $hook;
          $cache[$hook]['theme path'] = $path;
        }
        // Ensure uniqueness.
        $cache[$hook]['preprocess functions'] = array_unique($cache[$hook]['preprocess functions']);
      }
    }
  }
}