How to find out which form I want to alter I am adding a functionality to drupal commerce kickstart, which involves product display modification. There should be a lot of forms but I don't which one to alter and add my new object to the existed form. Any good idea? (There is almost no documentation about it)
The way I usually do it is just implement hook_form_alter and inside put dpm($form_id);. Reload the page and it will echo all form ID's. You should find the one you want pretty easily, you can then change the hook_form_alter into a hook_form_FORM_ID_alter.