multipage_form_example.module

<?php


/**
 * Implementation of hook_help().
 */
function multipage_form_example_help($section) {
  switch ($section) {
    case 'admin/modules#description':
      return t('An example module showing how to handle multipage forms in FAPI.');
    case 'node/add#multipage_form_example':
      return t('This will show you an example multipage form submission.');
  }
}

/**
 * Implementation of hook_menu().
 */
function multipage_form_example_menu($may_cache) {
  $items = array();

  if (!$may_cache) {

    $items[] = array('title'    => t('multipage form example'),
                     'path'     => 'node/add/multipage_form_example',
                     'access'   => TRUE,
    );
  }

  return $items;
}

/**
 * Implementation of hook_access().
 */
function multipage_form_example_access($op, $node) {
  return TRUE;
}

/**
 * Implementation of hook_node_info().
 */
function multipage_form_example_node_info() {
  return array('multipage_form_example' => array('name' => t('multipage form example'), 'base' => 'multipage_form_example'));
}

/**
 * Implementation of hook_form() for multipage_form_example. We don't set ANY
 * #required attributes here - we leave that up to multipage_form_example_pre_render().
 */
function multipage_form_example_form(&$node) {
  $form = array();

  // 'checkboxes' elements are just ridiculously hard--i recommend just
  //  using a bunch of individual checkbox elements instead.
  //  I suspect that multiselects would also be pretty difficult...

  // Here's a new form element, which enables you to store hidden values
  // in an array.  Check out the element definition functions at the bottom
  // if you want to use this in a module.  Keys show up in the
  // $_POST/$form_values like:
  // $_POST['edit']['test_hidden_array']['n'] = 'north'
  // $form_values['test_hidden_array']['n'] = 'north'

  $form['test_hidden_array'] = array(
    '#type'          => 'hidden_array',
    '#values'        => array('n' => 'north', 'e' => 'east', 'w' => 'west', 's' => 'south', ),
  );



  // Helper for our multipage - does field switching, sets options
  // based on validated $form_values instead of $_POST, and so forth.
  $form['#pre_render'] = array('multipage_form_example_pre_render');

  // Title and body, page 1
  $form['title'] = array(
    '#type'          => 'textfield',
    '#title'         => t('Title'),
    '#default_value' => isset($node->title) ? $node->title : NULL,
    '#description'   => t("Enter a title for your favorites section."),
    '#size'          => 60,
    '#maxlength'     => 128,
    '#required'      => TRUE,
  );
  $form['body'] = array(
    '#type'          => 'textarea',
    '#title'         => t('Description'),
    '#default_value' => isset($node->body) ? $node->body : NULL,
    '#description'   => t('Add any additional info about your favorites.'),
    '#rows'          => 20,
  );

  // Person, page 2
  $form['person'] = array(
    '#type'          => 'fieldset',
    '#title'         => t('Your favorite person'),
  );
  $form['person']['fav_person'] = array(
    '#type'          => 'textfield',
    '#title'         => t('Name'),
    '#default_value' => isset($node->fav_person) ? $node->fav_person : NULL,
    '#description'   => t('Enter their real name, or their code name if they like to fly stealth.'),
    '#required'      => TRUE,
  );
  $form['person']['fav_person_desc'] = array(
    '#type'          => 'textarea',
    '#title'         => t('Description'),
    '#default_value' => isset($node->fav_person_desc) ? $node->fav_person_desc : NULL,
    '#description'   => t('Juicy details go here...'),
    '#required'      => TRUE,
  );
  $form['person']['fav_gummi'] = array(
    '#type'          => 'checkbox',
    '#default_value' => isset($node->fav_gummi) ? $node->fav_gummi : 0,
    '#title'         => t('Do they like gummi bears?'),
  );

  // Color and number, page 3
  $form['fav_color'] = array(
    '#type'          => 'select',
    '#title'         => t('Favorite color'),
    '#default_value' => isset($node->fav_color) ? $node->fav_color : 'red',
    '#options'       => array('red' => t('Red'), 'green' => t('Green'), 'blue' => t('Blue'), 'yellow' => t('Yellow')),
    '#required'      => TRUE,
  );
  $form['fav_number'] = array(
    '#type'          => 'textfield',
    '#title'         => t('Favorite number'),
    '#default_value' => isset($node->fav_number) ? $node->fav_number : NULL,
    '#required'      => TRUE,
  );

  // Movie and tv show, page 4
  $form['fav_movie'] = array(
    '#type'          => 'textfield',
    '#title'         => t('Favorite movie'),
    '#default_value' => isset($node->fav_movie) ? $node->fav_movie : NULL,
    '#required'      => TRUE,
  );
  $form['fav_tv'] = array(
    '#type'          => 'radios',
    '#title'         => t('How often do you watch your favorite tv show?'),
    '#default_value' => isset($node->fav_tv) ? $node->fav_tv : 'daily',
    '#options'       => array('daily' => t('Daily'), 'weekly' => t('Weekly'), 'monthly' => t('Monthly'),),
    '#required'      => TRUE,
  );

  // Add a back button
  $form['back'] = array(
    '#type'          => 'button',
    '#value'         => t('Back'),
    '#weight'        => 35,
  );

  return $form;
}

function theme_multipage_form_example_node_form($form) {
  $content = '';

  if (in_array($form['page']['#value'], array(3,4))) {
    $content .= '<p>'. t('Your favorite person is %person, and they %like gummi bears.', array('%person' => check_plain($form['person']['fav_person']['#value']), '%like' => ($form['person']['fav_gummi']['#value'] ? t('like') : t('don\'t like')))) .'</p>';
  }

  if (in_array($form['page']['#value'], array(4))) {
    $content .= '<p>'. t('Your favorite color is %color, and your favorite number is %number.', array('%color' => check_plain($form['fav_color']['#value']), '%number' => check_plain($form['fav_number']['#value'])));
  }

  foreach (element_children($form) as $key) {
    $content .= form_render($form[$key]);
  }
  return $content;
}

/**
 * Implementation of hook_form_alter(). Here, we set up the 'page' field,
 * which keeps track of what stage the form is in.
 */
function multipage_form_example_form_alter($form_id, &$form) {
  // Make sure it's our multipage form.
  if ($form_id == 'multipage_form_example_node_form') {

    // Determine which page of the multipage form we're on. We don't do
    // any incrementing here - that's something that our #pre_render'er
    // will do when this page of the form has successfully validated.
    $form['page'] = array(
      '#type' => 'hidden',
      '#value' => isset($_POST['edit']['page']) ? $_POST['edit']['page'] : 1,
    );

    // If back button is pressed, back up the form stage, Also, if preview
    // is hit we need to decrement the counter here to keep us on the same page.
    if ($_POST['op'] == t('Back')) {
      $form['page']['#value']--;
    }

    // This modifies the form for validation purposes. once validation is
    // completed, it'll be called one more time (through Drupal's Form API)
    // at which point it'll advance the form to the next page.
    multipage_form_example_pre_render($form_id, $form, FALSE);

    // Here we're augmenting the regular node form validation/submission with
    // some of our own.  Note that these are inside the conditional check for
    // this particular form.
    $form['#validate'] = array_merge($form['#validate'], array('multipage_form_example_custom_validate' => array()));
    $form['#submit'] = array_merge($form['#submit'], array('multipage_form_example_custom_submit' => array()));
  }

  return $form;
}

/**
 * Validate our form.
 */
function multipage_form_example_custom_validate() {
  global $form_values;
  // validate our number, but don't bother if the back button was hit
  if (($form_values['page'] ==  3 ) && !is_numeric($form_values['fav_number']) && ($_POST['op'] != t('Back'))) {
    form_set_error('fav_number', t('Favorite number is a <em>number</em>, dummy!'));
  }
}

/**
 * The #pre_render of a form allows us to make changes AFTER validation (unlike
 * hook_form_alter()), but BEFORE the form has actually been displayed. We use
 * it to control which form elements are shown, which are hidden, and which values
 * to set based on validate elements, not $_POST. This is a necessity for our
 * complicated multipage example form.
 */
function multipage_form_example_pre_render($form_id, &$form, $next_page = TRUE) {
  global $form_values;

  // Make sure it's our multipage form.
  if ($form_id == 'multipage_form_example_node_form') {
    // Are we ready for the next page in our form?
    if ($next_page && isset($_POST['edit']['page']) && ($_POST['op'] != t('Back')) && ($_POST['op'] != t('Preview'))) {
      $form['page']['#value'] = $form['page']['#value'] + 1;
    }

    // Validation errors? Show previous page for correcting.
    if (form_get_errors()) {
      $form['page']['#value']--;
    }

    // Modify the #required/#type values depending on our current page.
    // The arrays tell us the pages the changes should take place in.

    // Title/body, stage 1
    multipage_form_set_element_visibility($form['title'],                     in_array($form['page']['#value'], array(1)));
    multipage_form_set_element_visibility($form['body'],                      in_array($form['page']['#value'], array(1)));

    // Person, stage 2
    multipage_form_set_element_visibility($form['person'],                    in_array($form['page']['#value'], array(2)));
    multipage_form_set_element_visibility($form['person']['fav_person'],      in_array($form['page']['#value'], array(2)));
    multipage_form_set_element_visibility($form['person']['fav_person_desc'], in_array($form['page']['#value'], array(2)));
    multipage_form_set_element_visibility($form['person']['fav_gummi'],       in_array($form['page']['#value'], array(2)), $next_page);

    // Color and number, page 3
    multipage_form_set_element_visibility($form['fav_color'],                 in_array($form['page']['#value'], array(3)));
    multipage_form_set_element_visibility($form['fav_number'],                in_array($form['page']['#value'], array(3)));

    // Movie and tv show, page 4
    multipage_form_set_element_visibility($form['fav_movie'],                 in_array($form['page']['#value'], array(4)));
    multipage_form_set_element_visibility($form['fav_tv'],                    in_array($form['page']['#value'], array(4)), $next_page);

    // Buttons
    multipage_form_set_element_visibility($form['back'],                      in_array($form['page']['#value'], array(2, 3, 4)), $next_page);
    multipage_form_set_element_visibility($form['preview'],                   in_array($form['page']['#value'], array(4)), $next_page);
    multipage_form_set_element_visibility($form['submit'],                    in_array($form['page']['#value'], array(4)), $next_page);

    // The button text actually helps determine if a form has actually been
    // submitted because the name is also the value of a clicked button. By
    // changing it for building, but not rendering, the form is not fully
    // sumbitted until we name it 'Submit', the usual value.
    if ($next_page) {
      $submit_text = array(NULL, t('Next (person)'), t('Next (color/number)'), t('Next (tv/movie)'), t('Submit'));
      $form['submit']['#value'] = $submit_text[$form['page']['#value']];
    }
  }
}

// Handles form submission.  We're just throwing our data into the variable
// table to keep things simple
function multipage_form_example_custom_submit() {
  global $form_values;
  foreach ($form_values as $key => $value) {
    if (in_array($key, array('fav_person', 'fav_person_desc', 'fav_gummi', 'fav_color', 'fav_number', 'fav_movie', 'fav_tv',))) {
      $array[$key] = $value;
    }
  }

    // A little hack so we can save new node info properly to the variable table
  if (isset($form_values['nid'])) {
    $nid = $form_values['nid'];
  }
  else {
    $nid = db_result(db_query("SELECT id FROM {sequences} WHERE name = 'node_nid'"));
  }

  variable_set('multipage_form_example_'. $nid, $array);
}

/**
 * Implementation of hook_load().
 *
 * Now that we've defined how to manage the node data in the database, We
 * need to tell Drupal how to get the node back out. This hook is called
 * every time a node is loaded, and allows us to do some loading of our own.
 */
function multipage_form_example_load($node) {
  $additions = variable_get('multipage_form_example_'. $node->nid, NULL);
  $additions = (object) $additions;
  return $additions;
}

/**
 * Implementation of hook_delete().
 *
 * Clean up our data in variable table.
 */
function multipage_form_example_delete($node) {
  // Notice that we're matching all revision, by using the node's nid.
  variable_del('multipage_form_example_'. $node->nid);
}

/**
 * Implementation of hook_view().
 *
 * This is a typical implementation that simply runs the node text through
 * the output filters.
 */
function multipage_form_example_view(&$node, $teaser = FALSE, $page = FALSE) {
  $node = node_prepare($node, $teaser);
  $favorites = theme('multipage_form_example', $node);
  $node->body .= $favorites;
  $node->teaser .= $favorites;
}

/**
 * A custom theme function.
 *
 * By using this function to format our node-specific information, themes
 * can override this presentation if they wish. We also wrap the default
 * presentation in a CSS class that is prefixed by the module name. This
 * way, style sheets can modify the output without requiring theme code.
 */
function theme_multipage_form_example($node) {
  $person_display = t('Your favorite person is %person, and they %like gummi bears. <br \>', array('%person' => check_plain($node->fav_person), '%like' => ($node->fav_gummi ? t('like') : t('don\'t like'))));
  $color_number_display = t('Your favorite color is %color, and your favorite number is %number. <br \>', array('%color' => check_plain($node->fav_color), '%number' => check_plain($node->fav_number)));
  $tv_movie_display = t('Your favorite movie is %movie, and you watch your favorite tv show %watch.', array('%movie' => check_plain($node->fav_movie), '%watch' => check_plain($node->fav_tv)));

  $output = '<div class="multipage_form_example">';
  $output .= $person_display . $color_number_display . $tv_movie_display;
  $output .= '</div>';

  return $output;
}

/**
 * Set an element's visibility. Elements are gnerally changed to hidden
 * elements. Visibility may be set and reset any number of times.
 *
 * @param $element
 *   The form element array to modify.
 * @param $visible
 *   The desired visibity of the form element.
 * @param $next_page
 *   Boolean value, TRUE if the next page is about to be rendered, FALSE otherwise.
 */
function multipage_form_set_element_visibility(&$element, $visible, $next_page = TRUE) {
  multipage_form_restore_attributes($element);
  if (!$visible) {
    switch ($element['#type']) {
      case 'textfield':
      case 'textarea':
      case 'select':
        multipage_form_set_attribute($element, '#type', 'hidden');
        multipage_form_set_attribute($element, '#required', FALSE);
        break;

      case 'radios':
        // Radios elements cannot be hidden unless they have been processed.
        if ($next_page) {
          multipage_form_set_attribute($element, '#type', 'hidden');
          multipage_form_set_attribute($element, '#required', FALSE);
        }
        break;

      case 'radio':
      case 'checkbox':
        // We can't change these to hidden until right before the next page is rendered, otherwise
        // the value is lost sometimes.
        if ($next_page) {
          multipage_form_set_attribute($element, '#type', 'hidden');
        }
        break;

      case 'fieldset':
        multipage_form_set_attribute($element, '#type', NULL);
        break;

      case 'button':
        if ($next_page) {
          multipage_form_set_attribute($element, '#type', 'value');
        }
        break;

      case 'submit':
        if ($next_page) {
          multipage_form_set_attribute($element, '#type', 'button');
        }
        break;
    }
  }

  foreach (element_children($element) as $key) {
    multipage_form_set_element_visibility($element[$key], $visible, $next_page);
  }
}

/**
 * Set an attribute on an element array with storing the previous value which
 * may be reverted to using multipage_form_restore_attributes().
 *
 * @param $element
 *   The form element array to modify.
 * @param $key
 *   A key of the form element array.
 * @param $new_value
 *   The new value for the attribute.
 */
function multipage_form_set_attribute(&$element, $key, $new_value) {
  $element['#multipage_form_original_'. $key] = $element[$key];
  $element[$key] = $new_value;
}

/**
 * Restore any form attributes which have been set using
 * multipage_form_set_attribute().
 *
 * @param $element
 *   The form element array to restore.
 */
function multipage_form_restore_attributes(&$element) {
  foreach (array_filter(array_keys($element), create_function('$key', 'return (strpos($key, "#multipage_form_original_") === 0);')) as $key) {
    $element[str_replace('#multipage_form_original_', '', $key)] = $element[$key];
  }
}

/**
 * Playing around here with a new form element to enable storing hidden values in an array fashion.
 * Seems to work fine.  Check out $form['test_hidden_array'] above for how to structure the form
 * element
 */
function multipage_form_example_elements() {
   $type['hidden_array'] = array('#input' => TRUE, '#process' => array('expand_hidden_array' => array()), '#tree' => TRUE);
   return $type;
}

function expand_hidden_array($element) {
  $values = is_array($element['#values']) ? $element['#values'] : array();
  $element['#tree'] = TRUE;
  foreach ($values as $key => $value) {
    $element[$key] = array('#type' => 'hidden', '#processed' => TRUE, '#value' => $value);
  }
  return $element;
}

function theme_hidden_array($element) {
  return $element['#children'];
}