function _theme_build_registry

Builds the theme registry cache.

Parameters

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

$base_theme: An array of loaded $theme objects representing the ancestor themes in oldest first order.

$theme_engine: The name of the theme engine.

File

includes/theme.inc, line 678

Code

function _theme_build_registry($theme, $base_theme, $theme_engine) {
    $cache = array();
    // First, process the theme hooks advertised by modules. This will
    // serve as the basic registry. Since the list of enabled modules is the same
    // regardless of the theme used, this is cached in its own entry to save
    // building it for every theme.
    if ($cached = cache_get('theme_registry:build:modules')) {
        $cache = $cached->data;
    }
    else {
        foreach (module_implements('theme') as $module) {
            _theme_process_registry($cache, $module, 'module', $module, drupal_get_path('module', $module));
        }
        // Only cache this registry if all modules are loaded.
        if (module_load_all(NULL)) {
            cache_set('theme_registry:build:modules', $cache);
        }
    }
    // Process each base theme.
    foreach ($base_theme as $base) {
        // If the base theme uses a theme engine, process its hooks.
        $base_path = dirname($base->filename);
        if ($theme_engine) {
            _theme_process_registry($cache, $theme_engine, 'base_theme_engine', $base->name, $base_path);
        }
        _theme_process_registry($cache, $base->name, 'base_theme', $base->name, $base_path);
    }
    // And then the same thing, but for the theme.
    if ($theme_engine) {
        _theme_process_registry($cache, $theme_engine, 'theme_engine', $theme->name, dirname($theme->filename));
    }
    // Finally, hooks provided by the theme itself.
    _theme_process_registry($cache, $theme->name, 'theme', $theme->name, dirname($theme->filename));
    // Let modules alter the registry.
    drupal_alter('theme_registry', $cache);
    // Optimize the registry to not have empty arrays for functions.
    foreach ($cache as $hook => $info) {
        foreach (array(
            'preprocess functions',
            'process functions',
        ) as $phase) {
            if (empty($info[$phase])) {
                unset($cache[$hook][$phase]);
            }
        }
    }
    return $cache;
}