Drupal 8 Form with custom action - php

Question

I have created a ModalDialog in Drupal contain two forms like as follows,
public function signUpForm() {
$response = new AjaxResponse();
// Get the modal form using the form builder.
$modal_form[] = $this->formBuilder->getForm('Drupal\signup_form\Form\SignupForm');
$modal_form[] = $this->formBuilder->getForm('Drupal\signup_form\Form\SigninForm');
// Add an AJAX command to open a modal dialog with the form as the content.
$response->addCommand(new OpenModalDialogCommand('', $modal_form, ['width' => '800','dialogClass' => 'signup-modal']));
return $response;
}
The forms are rendered, But the problem is ,both forms are submitting to the same function. I am unable to change the action of the form.
Is there any options available to change the form action to a custom url?

Answer 1

You need to alter these forms so that you can add your own submit handlers (and remove the unwanted one), and eventually from there you will be able to set the appropriate redirect, or AjaxResponse.
For example, for each form, implement hook_form_alter from a custom module :
function MODULE_signup_form_alter(&$form, FormStateInterface $form_state, $form_id) {
$form['actions']['submit']['#attributes']['class'][] = 'use-ajax-submit';
$form['actions']['submit']['#submit'][] = 'MODULE_signup_form_ajax_submit';
}
Then add the appropriate submit handlers, eg. :
function MODULE_signup_form_ajax_submit(array $form, FormStateInterface &$form_state) {
$response = new AjaxResponse();
$form-class = '.signup-form'; # using your own selector
$selector = '#drupal-modal' . ' ' . $form-class;
$message = '<div>submitted</div>';
$response->addCommand(new ReplaceCommand($selector, $message));
$form_state->setResponse($response);
}
I assumed you want to update the modal content so that the second form can still be submitted, so here I added the 'use-ajax-submit' class (cf. Drupal.behaviors.AJAX) to the appropriate $form action attributes so that the submit response can be rendered in the modal as well. Also used the ReplaceCommand to replace the submitted form content with a simple message.
If instead the first submitted form should trigger a redirection, then don't use setResponse() (that actually cancels redirect), and use setRedirect() if the base action url is not the one that you want.