function hook_forms

I had some trouble implementing hook_forms at first, but after some tinkering this is what I have worked out as a solution to printing multiple versions of the same form on one page:

1. Create your form builder like normal:
   <?php
function mymodule_form($form_state, $args){…}
?>
2. Call your form with drupal_get_form() (multiple times) with a key appended to the form_id:
   <?php
//normal call to get form, but append a key (of your own creation, e.g. a nid, or a static counting variable) to the end of the argument.
drupal_get_form('mymodule_form_'.$key)
?>
3. Create mymodule_forms function:
   <?php

   function mymodule_forms($form_id,$args){
   //Check if the form_id passed to drupal_get_form() contains the string 'mymodule_form'
     if (strpos($form_id, 'mymodule_form') !== FALSE) {
   //Lets attach mymodule_form to $forms[$form_id].  This effectively allows you to use the same form builder function to build a form with any form_id of your choice.
         $forms[$form_id] = array(
           'callback' => 'mymodule_form',
           );
         return $forms;
      }
   }
   ?>
4. Specify your submit function explicitly in your form builder function using the #submit element:
   <?php
function mymodule_form($form_state, $args){
//this is the function that will get called on form submission.
  $form['#submit'][] = 'mymodule_form_submit';
}
?>

Greetings,

Here is another example of a hook_forms implementation, using a more-or-less generic and reusable approach. One benefit of this method is that one has to go to fewer places to update form generation, validation, and submit code when dealing with multiple forms. I know this is a lengthy post, but this hook_forms process is somewhat non-intuitive, so I'm trying to give a complete (if silly) example for the sake of clarity.

hook forms

First set up a generic catch-all for your forms. In this case, I'm assuming that any $form_id value which starts with "mymodule_" will be a form generated by this module's code. In practice, you may want to narrow this down a little more, depending on the scope of your module's deployment, the uniqueness of your module's name (i.e. the collision probability), etc.

form builder

Next, build the form-array definitions (ref http://api.drupal.org/api/drupal/modules--node--node.module/function/nod...). Note that the $form_state var will likely be empty at this point, but can hold useful data if this form is being re-generated.

form validation

Perform whatever validation you deem appropriate for each form.

form submit / save

Validation has passed, so save the form values.

example usage

An example call to the new form might look something like this:

Or in a menu, like this:

Hi, I found this article really helpful when I needed to create multiple forms on a single page with different IDs so that submitting one didn't trigger the others to submit. But when I attempted to invoke the hook again in the same module I could not get the second function to run.

My code below is almost identical to similiar functions declared earlier in my module for a different page (chic_request_status_page) and the work fine. But in this second declaration my function chic_bookings_listing_update_forms is never entered. and I get all the forms with the correct IDs but there are no select or input elements from my chic_bookings_listing_update_form_builder function.

Hope this makes sense to someone,

-johnny;j