<?php
// $Id: prepopulate.module,v 1.5.2.1 2008-03-12 16:40:38 add1sun Exp $

/**
 * @file
 *  Fill form elements with data from GET.
 *
 *  Originally written by ea. Farris <eafarris@gmail.com>
 *  Based on an idea from chx, from the conversation at
 *  http://www.drupal.org/node/27155.
 */

/**
 * Implementation of hook_help().
 */
function prepopulate_help($section) {
  switch($section) {
    case 'admin/modules#description':
      return t('Pre-populates forms for allowed content types with HTTP GET data');
      break;
  } // endswitch $section
} // endfunction prepopulate_help()

/**
 * Implementation of hook_form_alter().
 */
function prepopulate_form_alter($form_id, &$form) {
  $node = $form['#node'];

  switch ($form_id) {
    // On a node settings form, praise be to the FormsAPI!
    case 'node_type_form':
      $type = $form['#node_type']->type;
      $form['workflow']['prepopulate_allowed'] = array(
        '#type' => 'checkbox',
        '#title' => 'Prepopulate form from URL?',
        '#default_value' => variable_get('prepopulate_allowed_' . $type, TRUE),
        '#description' => t('Allows fields to be prepopulated from the URL'),
      );
    return;
  } // endswitch $form_id

  if (isset($node)) {
    if (variable_get('prepopulate_allowed_'. $node->type, TRUE) && $_GET['edit']) {
      foreach (array_keys((array)$_GET['edit']) as $getvar) {
        if (element_child($getvar) && !is_null($form[$getvar])) {
          _prepopulate_get_walk($form[$getvar], $_GET['edit'][$getvar]);
        }
      } // endforeach get variable
    } // endif any get vars
  }
  
} // endfunction prepopulate_form_alter()

/**
 * Internal helper to get variables from the $_GET.
 */
function _prepopulate_get_walk(&$form, &$getslice) {
  if (!is_array($getslice)) {
    $form['#default_value'] = $getslice;
  } 
  else {
    foreach (array_keys($getslice) as $getvar) {
      if (element_child($getvar) && is_array($form) && !is_null($form[$getvar])) {
        _prepopulate_get_walk($form[$getvar], $getslice[$getvar]);
      }
    } // endforeach walking through get
  } // endif getslice is not an array
} // endfunction _prepopulate_get_walk()