function FormAjaxResponseBuilder::buildResponse

Overrides FormAjaxResponseBuilderInterface::buildResponse

File

core/lib/Drupal/Core/Form/FormAjaxResponseBuilder.php, line 50

Class

FormAjaxResponseBuilder

Builds an AJAX form response.

Namespace

Code

public function buildResponse(Request $request, array $form, FormStateInterface $form_state, array $commands) {
    // If the form build ID has changed, issue an Ajax command to update it.
    if (isset($form['#build_id_old']) && $form['#build_id_old'] !== $form['#build_id']) {
        $commands[] = new UpdateBuildIdCommand($form['#build_id_old'], $form['#build_id']);
    }
    // We need to return the part of the form (or some other content) that needs
    // to be re-rendered so the browser can update the page with changed
    // content. It is up to the #ajax['callback'] function of the element (may
    // or may not be a button) that triggered the Ajax request to determine what
    // needs to be rendered.
    $callback = NULL;
    if (($triggering_element = $form_state->getTriggeringElement()) && isset($triggering_element['#ajax']['callback'])) {
        $callback = $triggering_element['#ajax']['callback'];
    }
    $callback = $form_state->prepareCallback($callback);
    if (empty($callback) || !is_callable($callback)) {
        throw new HttpException(500, 'The specified #ajax callback is empty or not callable.');
    }
    $result = call_user_func_array($callback, [
        &$form,
        &$form_state,
        $request,
    ]);
    // If the callback is an #ajax callback, the result is a render array, and
    // we need to turn it into an AJAX response, so that we can add any commands
    // we got earlier; typically the UpdateBuildIdCommand when handling an AJAX
    // submit from a cached page.
    if ($result instanceof AjaxResponse) {
        $response = $result;
    }
    else {
        // At this point we know callback returned a render element. If the
        // element is part of the group (#group is set on it) it won't be rendered
        // unless we remove #group from it. This is caused by
        // \Drupal\Core\Render\Element\RenderElementBase::preRenderGroup(), which
        // prevents all members of groups from being rendered directly.
        if (!empty($result['#group'])) {
            unset($result['#group']);
        }
        
        /** @var \Drupal\Core\Ajax\AjaxResponse $response */
        $response = $this->ajaxRenderer
            ->renderResponse($result, $request, $this->routeMatch);
    }
    foreach ($commands as $command) {
        $response->addCommand($command, TRUE);
    }
    return $response;
}