How do I address the checkout button?

Question

I need to add a custom function to the Confirm Order button on a Commerce Checkout form. I can't figure out how to call it. The button ID is #edit-continue and its displayed text is Confirm Order. I thought this would show up in the $form[submit] array, but that array is empty. So I checked $form['buttons']['continue']['#submit'], which seems to be where Drupal Commerce stores the submit functions.

I created a module and two functions.

function MYMODULE_form_commerce_checkout_form_checkout_alter($form, $form_state, $form_id){ 
   drupal_set_message('ALTERING CHECKING OUT! THIS WORKS' . $form_id);   
   $form['buttons']['continue']['#value'] = 'Send Me A Quote!';
   $form['buttons']['continue']['#submit'][] = 'MYMODULE_submit';       

function MYMODULE_submit_function($form, &$form_state) {
  die('Triggered submit');
}

drupal_set_message() shows the message, but the submit function isn't invoked, and the text in the button is not altered. So clearly, the problem is that I am not targeting the button properly. How do I "address" that button?

To make it clearer, I need to overload that button, not replace the commerce checkout functionality.

PS: I have no access to the console or Devel. So I'm limited to debugging with var_dump().

Answer 1

Your changes to $form here are lost because you are passing by value. Pass by reference using &$form instead:

function MYMODULE_form_commerce_checkout_form_checkout_alter(&$form, &$form_state, $form_id) {

Answer 2

You must be using hook form alter so do a dpm($form) before adding the custom function to the submit handler and then do dpm($form) again after adding your custom handler and see if it shows your custom handler over there or not. dpm() will work if you have devel module installed otherwise do a var_dump() instead of dpm(), debugging the code should take you to the answer.

Answer 3

Based solely on the code you gave above, you've got at least one glaring issue. This code is okay:

function MYMODULE_form_commerce_checkout_form_checkout_alter($form, $form_state, $form_id){ 
   drupal_set_message('ALTERING CHECKING OUT! THIS WORKS' . $form_id);   
   $form['buttons']['continue']['#value'] = 'Send Me A Quote!';
   $form['buttons']['continue']['#submit'][] = 'MYMODULE_submit';  

However, in this block:

function MYMODULE_submit_function($form, &$form_state) {
  die('Triggered submit');
}

MYMODULE_submit_function should actually be the same as the handler you added in the form alter (i.e. MYMODULE_submit without the _function).

It's looking for that exact function name and won't add anything else to it like it does with the other form submit handlers that are called in drupal_get_form().