function rdf_get_namespaces

Retrieves RDF namespaces.

Invokes hook_rdf_namespaces() and collects RDF namespaces from modules that implement it.

Related topics

File

core/modules/rdf/rdf.module, line 113

Code

function rdf_get_namespaces() {
    $namespaces = [];
    // In order to resolve duplicate namespaces by using the earliest defined
    // namespace, do not use \Drupal::moduleHandler()->invokeAll().
    \Drupal::moduleHandler()->invokeAllWith('rdf_namespaces', function (callable $hook, string $module) use (&$namespaces) {
        $namespacesFromHook = $hook();
        foreach ($namespacesFromHook as $prefix => $namespace) {
            if (array_key_exists($prefix, $namespaces) && $namespace !== $namespaces[$prefix]) {
                throw new Exception("Tried to map '{$prefix}' to '{$namespace}', but '{$prefix}' is already mapped to '{$namespaces[$prefix]}'.");
            }
            else {
                $namespaces[$prefix] = $namespace;
            }
        }
    });
    return $namespaces;
}