iminimal ahah 6.x module

I don't know if this is the right spot either, but I'll post it now. Here is a sample (or demo) drupal 6.x module ahah with comments. I may follow with a screencast later, although this is simple and basic enough I'm not sure if one is needed.

<?php
// Minimal AHAH Form Implementation for 6.x
// Place these 2 files into /sites/all/modules/test
// test.module - this file.
/* test.info - should contain this:
name = "Test"
description = "For Testing."
core = "6.x"
version = "6.x-1.1"
 * * * */

define(TEST_WRAPPER,'ahah-will-replace-this-stuff');
define(TEST_PATH,'test/ahah');
define(TEST_TEXT_FORM_FIELD,'Test-Text-Body');

/** Implementation of menu_hook.  **/
function test_menu() {

  $items = array();

  // Setup the initial menu option.
  // yoursite/?q=test
  // if you use clear URLs  
  // yoursite/test  
  $items['test'] = array(
    'title' => 'Test setup',
    'description' => 'A simple test form.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array ('test_cb'),
    'access arguments' => array('access content'),
    'type' => MENU_NORMAL_ITEM
  );

  /**
   * This is the path in your site to the ajax/ahah callback function.
   */
  $items[TEST_PATH] = array(
    'title' => 'Test setup',
    'description' => 'A simple test AHAH callback.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array (
           // first argument is the callback function.
            'test_ahah_cb'),
    'access arguments' => array('access content'),
    'type' => MENU_NORMAL_ITEM
  );

  return $items;
}

/**
 * Here is our menu callback function (see menu_hook).
 * Just create a simple form with a single button.
 * @return drupal form array
 */
function test_cb(&$form_state) {
    $form['test'] = array (
    '#prefix' => '<div id="'.TEST_WRAPPER.'">',
    '#suffix' => '</div>',
    '#type' => 'fieldset',
    '#title' => 'Test Module...', 
    '#tree' => TRUE,
    );

    $form['test']['button'] = array (
    '#type' => 'submit',
    '#name' => 'Test Submit Button',
    '#value' => 'Push Me',
    '#id' => 'unique-test-id',
    '#ahah' => array(
        'path' => TEST_PATH,
        'event' => 'click',
        'wrapper' => TEST_WRAPPER,
        'progress' => array('type' => 'bar', 'message' => t('Grinding...')),
      ),    
    );
        
    $form['test']['check'] = array (
    '#prefix' => '<small>',
    '#suffix' => '</small>',
    '#type' => 'checkbox',
    '#name' => 'Display_Debugging',
    '#title' => 'Display Debug Fields',
    '#default_value' => FALSE,);
  
    return $form;
}

/**
 * This is the callback function for the ajax part.  
 * Return the original form, with some updated stuff on 
 * it.
 */
function test_ahah_cb() {
    
    // Unlike with normal 'submit' cb, $form and $form_state don't come
    // with ahah callbacks.  We need to get them from the cache.
    $form_state = array();
    $form_build_id = $_POST['form_build_id'];
    $form = form_get_cache($form_build_id, $form_state);
    
    // Now, set the fields in the old form the way we want them.
    // For this example we are adding a new field.
    $form['test']['body'] = array(
      '#type' => 'textfield',
      '#name' => TEST_TEXT_FORM_FIELD,
      '#title' => t('New Button Text'),
      '#size' => 40,
      '#maxlength' => 40,
      '#default_value' => 'You\'re Welcome',
      );        
    // If this is ahah cb, $_POST php global contains
    // info about the form that was posted.
    $value = 'Thank You';
    if (isset($_POST[TEST_TEXT_FORM_FIELD])) {
        $value = $_POST[TEST_TEXT_FORM_FIELD]; 
    }

    $form['test']['button']['#value']= $value;
      
        
    /**
     * Some debugging fields, we put our debug info into
     * fields since we can't use drupal_set_message.
     */
    $debug = isset($_POST['Display_Debugging']) &&
        ($_POST['Display_Debugging']== '1');
    $form['test']['check']['#default_value'] = $debug;
    _test_set_debugging($form,$form_state,$debug);
   
    // Now we need to save the form in the cache, so that future
    // submits will work with it.  Note that we could set stuff
    // in form_state['storage'] if we wanted to.
    form_set_cache($form_build_id, $form, $form_state);
    
    // Rebuild the form and display.
    $form = form_builder($_POST['form_id'], $form, $form_state);
    $output = drupal_render($form);     
    print drupal_to_js(array('data' => $output, 'status' => true));
    exit();         
}

/**
 * Set some debugging fields for ahah debugging.
 *
 * @param drupal form $form
 * @param drupal form_state $form_state
 * @param boolean $debug
 */
function _test_set_debugging(&$form,&$form_state,$debug) {
    if ($debug) {
        ob_start();
        var_dump($form);
        $debug_text = ob_get_clean();
        $form['test']['debugform'] = array(
          '#type' => 'textarea',
          '#name' => 'Debug-Text-Body',
          '#title' => t('Stuff in the form'),
          '#default_value' => $debug_text,
          );    
        ob_start();
        var_dump($_POST);
        $debug_text = ob_get_clean();
        $form['test']['debugpost'] = array(
          '#type' => 'textarea',
          '#name' => 'Debug-Post-Body',
          '#title' => t('Stuff in $_POST'),
          '#default_value' => $debug_text,
          );    
        ob_start();
        var_dump($form_state);
        $debug_text = ob_get_clean();
          $form['test']['debugstate'] = array(
          '#type' => 'textarea',
          '#name' => 'Debug-Post-Body',
          '#title' => t('Stuff in $form_state'),
          '#default_value' => $debug_text,
          );    
    } else {
        unset($form['test']['debugstate']);    
        unset($form['test']['debugform']);    
        unset($form['test']['debugpost']);    
    }            
}

?>