webform_references.node.inc in Webform References 7

Webform module node reference component.

File

webform_references.node.inc

<?php

/**
 * @file
 * Webform module node reference component.
 */

/**
 * Implements _webform_defaults_component().
 */
function _webform_defaults_node_reference() {
  return array(
    'name' => '',
    'form_key' => NULL,
    'required' => 0,
    'mandatory' => 0,
    'pid' => 0,
    'weight' => 0,
    'extra' => array(
      'title_display' => 0,
      'private' => FALSE,
      'attributes' => array(),
      'default_value' => NULL,
      'description' => '',
      'referenceable_types' => array(),
      'widget_type' => '',
      'empty_option' => 'None',
      'multiple' => NULL,
      'sort' => array(
        'sort_by' => 'nid',
        'order' => 'ASC',
      ),
      'use_view' => FALSE,
      'reference_view' => NULL,
      'view_args' => NULL,
    ),
  );
}

/**
 * Generate the form for editing a component.
 *
 * Create a set of form elements to be displayed on the form for editing this
 * component. Use care naming the form items, as this correlates directly to the
 * database schema. The component "Name" and "Description" fields are added to
 * every component type and are not necessary to specify here (although they
 * may be overridden if desired).
 *
 * @param array $component
 *   A Webform component array.
 *
 * @return array
 *   An array of form items to be displayed on the edit component page
 */
function _webform_edit_node_reference(array $component) {
  $form = array();
  $form['extra']['widget_type'] = array(
    '#type' => 'select',
    '#title' => t('Field Type'),
    '#multiple' => FALSE,
    '#default_value' => $component['extra']['widget_type'],
    '#options' => array(
      'select' => t('Select List'),
      'checkbox_radio' => t('Checkbox/Radio'),
      'autocomplete' => t('Autocomplete'),
    ),
    '#required' => TRUE,
  );
  $form['extra']['multiple'] = array(
    '#type' => 'checkbox',
    '#title' => t('Multiple'),
    '#default_value' => $component['extra']['multiple'],
    '#description' => t('Check this option if the user should be allowed to choose multiple values.'),
    '#states' => array(
      // Hide this field when the widget_type is autocomplete.
      'invisible' => array(
        ':input[name="extra[widget_type]"]' => array(
          'value' => 'autocomplete',
        ),
      ),
    ),
  );
  $form['extra']['use_view'] = array(
    '#type' => 'checkbox',
    '#title' => t('Use a view'),
    '#default_value' => $component['extra']['use_view'],
    '#description' => t('Use an entity reference view to select options.'),
  );
  if (!module_exists('entityreference')) {
    $form['extra']['use_view']['#disabled'] = 'disabled';
    $form['extra']['use_view']['#description'] = t('The entityreference module must be enabled to use this feature.');
  }
  $form['extra']['referenceable_types'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Content types that can be referenced'),
    '#multiple' => TRUE,
    '#default_value' => $component['extra']['referenceable_types'],
    '#options' => node_type_get_names(),
    '#element_validate' => array(
      '_webform_reference_node_types_validate',
    ),
    '#states' => array(
      'visible' => array(
        ':input[name="extra[use_view]"]' => array(
          'checked' => FALSE,
        ),
      ),
      'required' => array(
        ':input[name="extra[use_view]"]' => array(
          'checked' => FALSE,
        ),
      ),
    ),
  );

  // Filter views that list the entity type we want, and group the separate
  // displays by view.
  $displays = views_get_applicable_views('entityreference display');
  $options = array();
  foreach ($displays as $data) {
    list($view, $display_id) = $data;
    if ($view->base_table == 'node') {
      $options[$view->name . ':' . $display_id] = $view->name . ' - ' . $view->display[$display_id]->display_title;
    }
  }
  $form['extra']['reference_view'] = array(
    '#type' => 'select',
    '#title' => t('Select a view'),
    '#multiple' => FALSE,
    '#default_value' => $component['extra']['reference_view'],
    '#options' => $options,
    '#element_validate' => array(
      '_webform_references_node_reference_view_validate',
    ),
    '#states' => array(
      'visible' => array(
        ':input[name="extra[use_view]"]' => array(
          'checked' => TRUE,
        ),
      ),
      'required' => array(
        ':input[name="extra[use_view]"]' => array(
          'checked' => TRUE,
        ),
      ),
    ),
  );
  $form['extra']['view_args'] = array(
    '#type' => 'textfield',
    '#title' => t('Arguments to pass to the view'),
    '#description' => t('Arguments in the form arg1/arg2/arg3'),
    '#default_value' => $component['extra']['view_args'],
    '#states' => array(
      'visible' => array(
        ':input[name="extra[use_view]"]' => array(
          'checked' => TRUE,
        ),
      ),
    ),
  );
  $form['extra']['default_value'] = array(
    '#type' => 'textfield',
    '#title' => t('Default value'),
    '#default_value' => $component['extra']['default_value'],
    '#description' => t('The default value of the field.') . ' ' . theme('webform_token_help'),
  );
  $form['extra']['empty_option'] = array(
    '#type' => 'textfield',
    '#title' => t('Empty Option'),
    '#default_value' => $component['extra']['empty_option'],
    '#description' => t('Empty option value for select list.'),
    '#states' => array(
      'visible' => array(
        ':input[name="extra[widget_type]"]' => array(
          'value' => 'select',
        ),
        ':input[name="extra[multiple]"]' => array(
          'checked' => FALSE,
        ),
      ),
    ),
  );
  $form['extra']['sort'] = array(
    '#type' => 'container',
    '#attributes' => array(
      'class' => array(
        'container-inline',
      ),
    ),
  );
  $form['extra']['sort']['sort_by'] = array(
    '#type' => 'select',
    '#title' => t('Sort By'),
    '#multiple' => FALSE,
    '#default_value' => $component['extra']['sort']['sort_by'],
    '#options' => array(
      'nid' => t('Node Id'),
      'title' => t('Title'),
    ),
    '#required' => TRUE,
    '#states' => array(
      // Hide this field when the widget_type is autocomplete.
      'invisible' => array(
        ':input[name="extra[widget_type]"]' => array(
          'value' => 'autocomplete',
        ),
      ),
    ),
  );
  $form['extra']['sort']['order'] = array(
    '#type' => 'select',
    '#title' => t('Order'),
    '#multiple' => FALSE,
    '#default_value' => $component['extra']['sort']['order'],
    '#options' => array(
      'ASC' => t('Ascending'),
      'DESC' => t('Descending'),
    ),
    '#required' => TRUE,
    '#states' => array(
      // Hide this field when the widget_type is autocomplete.
      'invisible' => array(
        ':input[name="extra[widget_type]"]' => array(
          'value' => 'autocomplete',
        ),
      ),
    ),
  );
  return $form;
}

/**
 * This is a workaround, because currently FAPI states 'required' only
 * adds an asterisk but does not do validation. If we use the '#required'
 * attribute on the element itself then validation will fail on the invisible
 * referenceable type element
 *
 * @see _webform_edit_node_reference()
 */
function _webform_reference_node_types_validate($element, &$form_state) {
  $use_view = $form_state['complete form']['extra']['use_view']['#value'];
  if (!$use_view && empty($element['#value'])) {
    form_set_error($element['#name'], t('Please select at least one content type to be referenced.'));
  }
}

/**
 * To validate the reference view element in case of empty list.
 */
function _webform_references_node_reference_view_validate($element, &$form_state) {
  $use_view = $form_state['complete form']['extra']['use_view']['#value'];
  if ($use_view && empty($element['#value'])) {
    form_set_error($element['#name'], t('Please select any view to be referenced.'));
  }
}

/**
 * Render a Webform component to be part of a form.
 *
 * @param array $component
 *   A Webform component array.
 * @param array $value
 *   If editing an existing submission or resuming a draft, this will contain
 *   an array of values to be shown instead of the default in the component
 *   configuration. This value will always be an array, keyed numerically for
 *   each value saved in this field.
 * @param string $filter
 *   Whether or not to filter the contents of descriptions and values when
 *   rendering the component. Values need to be unfiltered to be editable by
 *   Form Builder.
 *
 * @see _webform_client_form_add_component()
 */
function _webform_render_node_reference(array $component, array $value = NULL, $filter = TRUE) {
  $default_value = array(
    $filter ? webform_replace_tokens($component['extra']['default_value']) : $component['extra']['default_value'],
  );
  switch ($component['extra']['widget_type']) {
    case 'autocomplete':
      if (!empty($component['extra']['use_view'])) {
        $path = 'webform_references/view/autocomplete/node/' . str_replace(':', '/', $component['extra']['reference_view']);
        if (!empty($component['extra']['view_args'])) {
          $path .= '/' . $component['extra']['view_args'];
        }
      }
      else {
        $path = 'webform_references/node/autocomplete/' . implode('+', array_filter($component['extra']['referenceable_types']));
      }
      $form_item = array(
        '#type' => 'textfield',
        '#autocomplete_path' => $path,
        '#description' => $filter ? _webform_filter_descriptions($component['extra']['description']) : $component['extra']['description'],
        '#required' => $component['required'] || $component['mandatory'],
        // Either one being true will could as required...
        // because webform changed in 4.x-alpha8
        '#maxlength' => NULL,
        '#title' => $filter ? _webform_filter_xss($component['name']) : $component['name'],
        '#title_display' => $component['extra']['title_display'] ? $component['extra']['title_display'] : 'before',
        '#weight' => $component['weight'],
        '#element_validate' => array(
          'webform_references_validate_node_reference',
        ),
        '#theme_wrappers' => array(
          'webform_element',
        ),
        '#translatable' => array(
          'title',
          'description',
        ),
      );
      if (isset($value)) {
        $selected_node = node_load($value[0]);
        $form_item['#default_value'] = $selected_node ? $selected_node->title . " [id:{$selected_node->nid}]" : '';
      }
      elseif (isset($default_value)) {
        $selected_node = node_load($default_value[0]);
        $form_item['#default_value'] = $selected_node ? $selected_node->title . " [id:{$selected_node->nid}]" : '';
      }
      break;
    case 'checkbox_radio':
      if (empty($component['extra']['use_view'])) {
        $node_list = _webform_references_get_node_list($component['extra']['referenceable_types'], $component['extra']['sort']['sort_by'], $component['extra']['sort']['order']);
      }
      else {
        $node_list = _webform_references_list_from_view($component['extra']['reference_view'], 'node', $component['extra']['view_args']);
      }
      $form_item = array(
        '#type' => $component['extra']['multiple'] ? 'checkboxes' : 'radios',
        '#description' => $filter ? _webform_filter_descriptions($component['extra']['description']) : $component['extra']['description'],
        '#required' => $component['required'] || $component['mandatory'],
        // Either one being true will could as required...
        // because webform changed in 4.x-alpha8.
        '#title' => $filter ? _webform_filter_xss($component['name']) : $component['name'],
        '#title_display' => $component['extra']['title_display'] ? $component['extra']['title_display'] : 'before',
        '#options' => $node_list,
        '#multiple' => $component['extra']['multiple'],
        '#weight' => $component['weight'],
        '#pre_render' => array(),
        '#translatable' => array(
          'title',
          'description',
        ),
      );
      $form_item['#theme_wrappers'] = array(
        $form_item['#type'],
        'webform_element',
      );
      if (isset($value)) {
        if ($form_item['#type'] == 'checkboxes') {
          $form_item['#default_value'] = $value;
        }
        else {
          $form_item['#default_value'] = $value[0];
        }
      }
      elseif (isset($default_value)) {
        if ($form_item['#type'] == 'checkboxes') {
          $form_item['#default_value'] = $default_value;
        }
        else {
          $form_item['#default_value'] = $default_value[0];
        }
      }
      break;
    default:
      if (empty($component['extra']['use_view'])) {
        $node_list = _webform_references_get_node_list($component['extra']['referenceable_types'], $component['extra']['sort']['sort_by'], $component['extra']['sort']['order']);
      }
      else {
        $node_list = _webform_references_list_from_view($component['extra']['reference_view'], 'node', $component['extra']['view_args']);
      }
      $form_item = array(
        '#type' => 'select',
        '#description' => $filter ? _webform_filter_descriptions($component['extra']['description']) : $component['extra']['description'],
        '#required' => $component['required'] || $component['mandatory'],
        // Either one being true will could as required...
        // because webform changed in 4.x-alpha8.
        '#title' => $filter ? _webform_filter_xss($component['name']) : $component['name'],
        '#title_display' => $component['extra']['title_display'] ? $component['extra']['title_display'] : 'before',
        '#options' => $node_list,
        '#empty_option' => trim($component['extra']['empty_option']) != '' ? $component['extra']['empty_option'] : t('No Value'),
        '#weight' => $component['weight'],
        '#multiple' => $component['extra']['multiple'],
        '#theme_wrappers' => array(
          'webform_element',
        ),
        '#translatable' => array(
          'title',
          'description',
        ),
      );
      if (isset($value)) {
        $form_item['#default_value'] = $value;
      }
      elseif (isset($default_value)) {
        $form_item['#default_value'] = $default_value;
      }
      break;
  }
  return $form_item;
}

/**
 * Validation Callback for node reference field.
 */
function webform_references_validate_node_reference($element, $form_state) {
  $value = $element['#value'];
  $nid = NULL;
  if (!empty($value)) {
    preg_match('/^(?:\\s*|(.*) )?\\[\\s*id\\s*:\\s*(\\d+)\\s*\\]$/', $value, $matches);
    if (!empty($matches)) {
      list(, $title, $nid) = $matches;
      $extra = $element['#webform_component']['extra'];
      if (!empty($extra['use_view'])) {
        list($view_name, $display_name) = explode(':', $extra['reference_view']);
        $args = !empty($extra['view_args']) ? explode('/', token_replace($extra['view_args'], array())) : NULL;
        $result = webform_references_execute_view($view_name, $display_name, 'node', $args, '', 'CONTAINS', 0, $matches[2]);
        if (count($result) != 1) {
          form_error($element, t('Please check your selection - views.'));
        }
      }
      else {
        if (!empty($title)) {
          $real_title = db_select('node', 'n')
            ->fields('n', array(
            'title',
          ))
            ->condition('n.nid', $nid)
            ->addTag('node_access')
            ->execute()
            ->fetchField();
          if (trim($title) != trim($real_title)) {
            form_error($element, t('Please check your selection.'));
          }
        }
      }
    }
    else {
      $options = array(
        'string' => $value,
        'match' => 'equals',
        'limit' => 1,
      );
      $bundle_args = explode('/', $element['#autocomplete_path']);
      $bundles = isset($bundle_args[2]) ? $bundle_args[2] : array();
      $references = webform_references_node_potential_references($bundles, $options);
      if ($references) {
        $nid = key($references);
      }
      else {
        form_error($element, t('Please check your selection.'));
      }
    }
  }
}

/**
 * A hook for changing the input values before saving to the database.
 *
 * Note that Webform will save the result of this function directly into the
 * database.
 *
 * @param array $component
 *   A Webform component array.
 * @param string $value
 *   The POST data associated with the user input.
 *
 * @return string
 *   A string of value to be saved into the database.
 */
function _webform_submit_node_reference(array $component, $value) {
  if ($component['extra']['widget_type'] == 'autocomplete') {
    preg_match('/^(?:\\s*|(.*) )?\\[\\s*id\\s*:\\s*(\\d+)\\s*\\]$/', $value, $matches);
    if (!empty($matches)) {
      list(, , $nid) = $matches;
      $value = $nid;
    }
  }
  return $value;
}

/**
 * Implements _webform_theme_component().
 */
function _webform_theme_node_reference() {
  return array(
    'webform_display_node_reference_field' => array(
      'render element' => 'element',
    ),
  );
}

/**
 * Display the result of a submission for a component.
 *
 * The output of this function will be displayed under the "Results" tab then
 * "Submissions". This should output the saved data in some reasonable manner.
 *
 * @param array $component
 *   A Webform component array.
 * @param array $value
 *   An array of information containing the submission result, directly
 *   correlating to the webform_submitted_data database table schema.
 *   or NULL if no value submitted.
 * @param string $format
 *   Either 'html' or 'text'. Defines the format that the content should be
 *   returned as. Make sure that returned content is run through check_plain()
 *   or other filtering functions when returning HTML.
 *
 * @return array
 *   A renderable element containing at the very least these properties:
 *    - #title
 *    - #weight
 *    - #component
 *    - #format
 *    - #value
 *   Webform also uses #theme_wrappers to output the end result to the user,
 *   which will properly format the label and content for use within an e-mail
 *   (such as wrapping the text) or as HTML (ensuring consistent output).
 */
function _webform_display_node_reference(array $component, $value, $format = 'html') {
  $value = (array) $value;
  return array(
    '#title' => $component['name'],
    '#weight' => $component['weight'],
    '#theme' => 'webform_display_node_reference_field',
    '#theme_wrappers' => $format == 'html' ? array(
      'webform_element',
    ) : array(
      'webform_element_text',
    ),
    '#post_render' => array(
      'webform_element_wrapper',
    ),
    '#component' => $component,
    '#format' => $format,
    '#value' => array_filter($value),
  );
}

/**
 * Format the output of data for this component.
 */
function theme_webform_display_node_reference_field($variables) {
  $values = (array) $variables['element']['#value'];
  $items = array();
  foreach (array_filter($values) as $value) {
    $nid = check_plain($value);
    $items[] = _webform_references_get_node_title($nid, TRUE);
  }
  $output = count($items) > 1 ? theme('item_list', array(
    'items' => $items,
  )) : (isset($items[0]) ? $items[0] : '');
  return $output;
}

/**
 * Helper function to get title of node.
 *
 * @param int $nid
 *   Node Id.
 * @param bool $link
 *   FALSE for plain text and TRUE for linked text.
 *
 * @return string
 *   Title of the node (Linked if $link parameter is set to TRUE).
 */
function _webform_references_get_node_title($nid, $link = FALSE) {
  $node_items = db_select('node', 'n')
    ->fields('n', array(
    'title',
  ))
    ->condition('nid', $nid)
    ->execute()
    ->fetchAssoc();
  $title = NULL;
  if (!empty($node_items)) {
    $title = $link == TRUE ? l($node_items['title'], 'node/' . $nid) : check_plain($node_items['title']);
  }
  return $title;
}

/**
 * Implements _webform_table_component().
 */
function _webform_table_node_reference(array $component, $value) {
  $value = (array) $value;
  $items = array();
  foreach (array_filter($value) as $nid) {
    $items[] = _webform_references_get_node_title($nid);
  }
  return !empty($items) ? implode('<br />', $items) : '';
}

/**
 * Return the header for this component to be displayed in a CSV file.
 *
 * The output of this function will be displayed under the "Results" tab then
 * "Download".
 *
 * @param array $component
 *   A Webform component array.
 * @param array $export_options
 *   An array of options that may configure export of this field.
 *
 * @return array
 *   An array of data to be displayed in the first three rows of a CSV file, not
 *   including either prefixed or trailing commas.
 */
function _webform_csv_headers_node_reference(array $component, array $export_options) {
  $header = array();
  $header[0] = '';
  $header[1] = '';
  $header[2] = $component['name'];
  return $header;
}

/**
 * Format the submitted data of a component for CSV downloading.
 *
 * The output of this function will be displayed under the "Results" tab then
 * "Download".
 *
 * @param array $component
 *   A Webform component array.
 * @param array $export_options
 *   An array of options that may configure export of this field.
 * @param array $value
 *   An array of information containing the submission result, directly
 *   correlating to the webform_submitted_data database schema.
 *   or NULL if no value submitted.
 *
 * @return string
 *   A string of item to be added to the CSV file.
 */
function _webform_csv_data_node_reference(array $component, array $export_options, $value) {
  $return = array();
  $value = (array) $value;
  foreach (array_filter($value) as $nid) {
    $return[] = _webform_references_get_node_title($nid);
  }
  return !empty($return) ? implode(', ', $return) : '';
}

/**
 * Menu callback for the autocomplete results.
 */
function webform_references_node_autocomplete($bundles, $string = '') {
  $options = array(
    'string' => $string,
    'limit' => 10,
  );
  $references = webform_references_node_potential_references($bundles, $options);
  $matches = array();
  foreach ($references as $id => $row) {

    // Markup is fine in autocompletion results (might happen when rendered
    // through Views) but we want to remove hyperlinks.
    $suggestion = preg_replace('/<a href="([^<]*)">([^<]*)<\\/a>/', '$2', $row['rendered']);

    // Add a class wrapper for a few required CSS overrides.
    $matches[$row['title'] . " [id:{$id}]"] = check_plain($suggestion);
  }
  drupal_json_output($matches);
}

/**
 * Retrieves an array of referenceable nodes.
 *
 * @param string $bundles
 *   List of content types separated by (+) sign to be referenced.
 * @param array $options
 *   An array of options to limit the scope of the returned list. The following
 *   key/value pairs are accepted:
 *   - string: string to filter titles on (used by autocomplete).
 *   - ids: array of specific node ids to lookup.
 *   - limit: maximum size of the the result set. Defaults to 0 (no limit).
 *
 * @return array
 *   An array of valid nodes in the form:
 *   array(
 *     nid => array(
 *       'title' => The node title,
 *       'rendered' => The text to display in widgets (can be HTML)
 *     ),
 *     ...
 *   )
 */
function webform_references_node_potential_references($bundles, $options = array()) {
  $options += array(
    'string' => '',
    'ids' => array(),
    'limit' => 0,
  );
  $results =& drupal_static(__FUNCTION__, array());

  // Create unique id for static cache.
  $cid = ($options['string'] !== '' ? $options['string'] : implode('-', $options['ids'])) . ':' . $options['limit'];
  if (!isset($results[$cid])) {
    $references = _webform_references_node_potential_references_standard($bundles, $options);

    // Store the results.
    $results[$cid] = !empty($references) ? $references : array();
  }
  return $results[$cid];
}

/**
 * Helper function for webform_references_node_potential_references().
 *
 * List of referenceable nodes defined by content types.
 */
function _webform_references_node_potential_references_standard($bundles, $options) {
  $bundles_array = explode('+', $bundles);
  if (!count($bundles_array)) {
    return array();
  }
  $query = db_select('node', 'n');
  $query
    ->addField('n', 'nid');
  $node_title_alias = $query
    ->addField('n', 'title', 'node_title');
  $node_type_alias = $query
    ->addField('n', 'type', 'node_type');
  $query
    ->addTag('node_access')
    ->addMetaData('id', ' _webform_references_node_potential_references_standard')
    ->addMetaData('options', $options);
  $query
    ->condition('n.status', NODE_PUBLISHED);
  if (is_array($bundles_array)) {
    $query
      ->condition('n.type', $bundles_array, 'IN');
  }
  if ($options['string'] !== '') {
    $query
      ->condition('n.title', '%' . $options['string'] . '%', 'LIKE');
  }
  if ($options['ids']) {
    $query
      ->condition('n.nid', $options['ids'], 'IN');
  }
  if ($options['limit']) {
    $query
      ->range(0, $options['limit']);
  }
  $query
    ->orderBy($node_title_alias)
    ->orderBy($node_type_alias);
  $result = $query
    ->execute()
    ->fetchAll();
  $references = array();
  foreach ($result as $node) {
    $references[$node->nid] = array(
      'title' => $node->node_title,
      'rendered' => $node->node_title,
    );
  }
  return $references;
}

/**
 * Helper function to get node list.
 */
function _webform_references_get_node_list($types, $sort_by = 'title', $order = 'ASC') {
  $result = db_select('node', 'n')
    ->fields('n', array(
    'nid',
    'title',
  ))
    ->condition('n.type', $types, 'IN')
    ->condition('n.status', NODE_PUBLISHED)
    ->orderBy($sort_by, $order)
    ->addTag('node_access')
    ->execute()
    ->fetchAll();
  $node_list = array();
  foreach ($result as $content) {
    $node_list[$content->nid] = $content->title;
  }
  return $node_list;
}

Functions

Name	Description
theme_webform_display_node_reference_field	Format the output of data for this component.
webform_references_node_autocomplete	Menu callback for the autocomplete results.
webform_references_node_potential_references	Retrieves an array of referenceable nodes.
webform_references_validate_node_reference	Validation Callback for node reference field.
_webform_csv_data_node_reference	Format the submitted data of a component for CSV downloading.
_webform_csv_headers_node_reference	Return the header for this component to be displayed in a CSV file.
_webform_defaults_node_reference	Implements _webform_defaults_component().
_webform_display_node_reference	Display the result of a submission for a component.
_webform_edit_node_reference	Generate the form for editing a component.
_webform_references_get_node_list	Helper function to get node list.
_webform_references_get_node_title	Helper function to get title of node.
_webform_references_node_potential_references_standard	Helper function for webform_references_node_potential_references().
_webform_references_node_reference_view_validate	To validate the reference view element in case of empty list.
_webform_reference_node_types_validate	This is a workaround, because currently FAPI states 'required' only adds an asterisk but does not do validation. If we use the '#required' attribute on the element itself then validation will fail on the invisible referenceable…
_webform_render_node_reference	Render a Webform component to be part of a form.
_webform_submit_node_reference	A hook for changing the input values before saving to the database.
_webform_table_node_reference	Implements _webform_table_component().
_webform_theme_node_reference	Implements _webform_theme_component().