<?php
// $Id$

/**
 * @file
 * Provides a node type with a multi-step node form for testing.
 */

/**
 * Implementation of hook_node_info().
 */
function twostepnode_node_info() {
  return array(
    'twostepnode' => array(
      'name' => t('2-step node'),
      'module' => 'twostepnode',
      'description' => t('A node that uses a multi-step node form for testing.'),
    ),
  );
}

/**
 * Implementation of hook_form().
 */
function twostepnode_form(&$node, $form_state) {
  $form['title'] = array(
    '#title' => t('Title'),
    '#type' => 'textfield',
    '#required' => TRUE,
    '#default_value' => isset($form_state['storage']['title']) ? $form_state['storage']['title'] : $node->title,
  );
  $form['body_field'] = node_body_field($node, t('Required body'), 1);
  return $form;
}

/**
 * Implementation of hook_form_alter().
 *
 * When first adding the node, put the 'Title' field on its own page in a
 * multistep node form.  We need to do this in hook_form_alter() itself
 * instead of a form_id-specific form alter so that we're likely to come after
 * everyone else's alterings, e.g. taxonomy, menu, etc.
 */
function twostepnode_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == 'twostepnode_node_form') {
    $node = $form['#node'];
    if (empty($form_state['storage']['title']) && empty($node->title)) {
      _twostepnode_step1($form, array('title'));
    }
    else {
      // For the actual submit button, add a handler to clear out
      // $form_state['storage']['title'] so that we actually submit the form.
      $form['buttons']['submit']['#submit'][] = 'twostepnode_node_form_final_submit';
    }
  }
}

/**
 * Helper function to convert the node form into step 1 of a multi-step form.
 *
 * Marks all form elements to #access FALSE except those required on step 1,
 * converts the usual "preview" button into a "next" button and hides the
 * submit button.
 */
function _twostepnode_step1(&$form) {
  // Hide all the elements we don't want on step 1.
  foreach (element_children($form) as $child) {
    if ($child != 'buttons' &&
        (empty($form[$child]['#type']) ||
         ($form[$child]['#type'] != 'hidden'
          && $form[$child]['#type'] != 'value'
          && $form[$child]['#type'] != 'token'
          && ($child != 'title')))) {
      $form[$child]['#access'] = FALSE;
    }
  }

  // Change preview to next and hide submit.
  $form['buttons']['preview'] = array(
    '#type' => 'submit',
    '#value' => t('Next'),
    '#weight' => 50,
    '#submit' => array('twostepnode_node_form_next_handler'),
  );
  $form['buttons']['submit']['#access'] = FALSE;
}

/**
 * Submit handler for the 'Next' button on step 1.
 *
 * Saves the title value into $form_state['storage'].
 */
function twostepnode_node_form_next_handler($form, &$form_state) {
  if (isset($form_state['values']['title'])) {
    $form_state['storage']['title'] = $form_state['values']['title'];
  }
}

/**
 * Submit handler for the "Save" button on step 2.
 *
 * Clears out $form_state['storage']['title'] so the form will submit and will
 * not rebuild itself.
 */
function twostepnode_node_form_final_submit(&$form, &$form_state) {
  unset($form_state['storage']['title']);
}