path: root/modules/field/modules/options/options.module

<?php
// $Id$

/**
 * @file
 * Defines selection, check box and radio button widgets for text and numeric fields.
 */

/**
 * Implements hook_theme().
 */
function options_theme() {
  return array(
    'options_none' => array(
      'variables' => array('instance' => NULL),
    ),
  );
}

/**
 * Implements hook_field_widget_info().
 */
function options_field_widget_info() {
  return array(
    'options_select' => array(
      'label' => t('Select list'),
      'field types' => array('list', 'list_boolean', 'list_text', 'list_number'),
      'behaviors' => array(
        'multiple values' => FIELD_BEHAVIOR_CUSTOM,
      ),
    ),
    'options_buttons' => array(
      'label' => t('Check boxes/radio buttons'),
      'field types' => array('list', 'list_boolean', 'list_text', 'list_number'),
      'behaviors' => array(
        'multiple values' => FIELD_BEHAVIOR_CUSTOM,
      ),
    ),
    'options_onoff' => array(
      'label' => t('Single on/off checkbox'),
      'field types' => array('list_boolean'),
      'behaviors' => array(
        'multiple values' => FIELD_BEHAVIOR_CUSTOM,
      ),
    ),
  );
}

/**
 * Implements hook_field_widget().
 */
function options_field_widget(&$form, &$form_state, $field, $instance, $langcode, $items, $delta, $element) {
  // Abstract over the actual field columns, to allow different field types to
  // reuse those widgets.
  $value_key = key($field['columns']);
  $multiple = $field['cardinality'] > 1 || $field['cardinality'] == FIELD_CARDINALITY_UNLIMITED;
  // Form API 'checkboxes' do not suport 0 as an option, so we replace it with
  // a placeholder within the form workflow.
  $zero_placeholder = $instance['widget']['type'] == 'options_buttons' && $multiple;
  // Collect available options for the field.
  $options = options_get_options($field, $instance, $zero_placeholder);
  // Put current field values in shape.
  $default_value = _options_storage_to_form($items, $options, $value_key, $zero_placeholder);

  switch ($instance['widget']['type']) {
    case 'options_select':
      $element += array(
        '#type' => 'select',
        '#default_value' => $default_value,
        // Do not display a 'multiple' select box if there is only one option.
        '#multiple' => $multiple && count($options) > 1,
        '#options' => $options,
        '#value_key' => $value_key,
        '#element_validate' => array('options_field_widget_validate'),
      );
      break;

    case 'options_buttons':
      $type = $multiple ? 'checkboxes' : 'radios';
      // If required and there is one single option, preselect it.
      if ($element['#required'] && count($options) == 1) {
        $default_value = array(key($options));
      }
      $element += array(
        '#type' => $type,
        // Radio buttons need a scalar value.
        '#default_value' => ($type == 'radios') ? reset($default_value) : $default_value,
        '#options' => $options,
        '#zero_placeholder' => $zero_placeholder,
        '#value_key' => $value_key,
        '#element_validate' => array('options_field_widget_validate'),
      );
      break;

    case 'options_onoff':
      $keys = array_keys($options);
      $off_value = (!empty($keys) && isset($keys[0])) ? $keys[0] : NULL;
      $on_value = (!empty($keys) && isset($keys[1])) ? $keys[1] : NULL;
      $element += array(
        '#type' => 'checkbox',
        '#title' => isset($options[$on_value]) ? $options[$on_value] : '',
        '#default_value' => (isset($default_value[0]) && $default_value[0] == $on_value) ? 1 : 0,
        '#on_value' => $on_value,
        '#off_value' => $off_value,
        '#value_key' => $value_key,
        '#element_validate' => array('options_field_widget_validate'),
      );
      break;
  }

  return $element;
}

/**
 * Form element validation handler for options element.
 */
function options_field_widget_validate($element, &$form_state) {
  $field = $form_state['complete form']['#fields'][$element['#field_name']]['field'];
  $instance = $form_state['complete form']['#fields'][$element['#field_name']]['instance'];

  // Transpose selections from field => delta to delta => field, turning
  // multiple selected options into multiple parent elements.
  $items = _options_form_to_storage($element);
  form_set_value($element, $items, $form_state);

  // Check that we don't exceed the allowed number of values.
  if ($field['cardinality'] >= 2 && $field['cardinality'] != FIELD_CARDINALITY_UNLIMITED) {
    if (count($items) > $field['cardinality']) {
      form_error($element, t('%name: this field cannot hold more than @count values.', array('%name' => t($instance['label']), '@count' => $field['cardinality'])));
    }
  }
}

/**
 * Prepares the options for a field.
 */
function options_get_options($field, $instance, $zero_placeholder) {
  // Check if there is a module hook for the option values, otherwise try
  // list_allowed_values() for an options list.
  // @todo This should be turned into a hook_options_allowed_values(), exposed
  // by options.module.
  $function = $field['module'] . '_allowed_values';
  $options = function_exists($function) ? $function($field) : (array) list_allowed_values($field);

  // Substitute the '_0' placeholder.
  if ($zero_placeholder) {
    $values = array_keys($options);
    // Use a strict comparison, because 0 == 'any string'.
    $index = array_search(0, $values, TRUE);
    if ($index !== FALSE) {
      $values[$index] = '_0';
      $options = array_combine($values, array_values($options));
    }
  }

  // Add an empty choice for
  // - non required radios
  // - non required selects
  if (!$instance['required']) {
    if (($instance['widget']['type'] == 'options_buttons' && ($field['cardinality'] == 1)) || ($instance['widget']['type'] == 'options_select')) {
      $options = array('_none' => theme('options_none', array('instance' => $instance))) + $options;
    }
  }
  return $options;
}

/**
 * Transforms stored field values into the format the widgets need.
 */
function _options_storage_to_form($items, $options, $column, $zero_placeholder) {
  $items_transposed = options_array_transpose($items);
  $values = (isset($items_transposed[$column]) && is_array($items_transposed[$column])) ? $items_transposed[$column] : array();

  // Substitute the '_0' placeholder.
  if ($zero_placeholder) {
    $index = array_search('0', $values);
    if ($index !== FALSE) {
      $values[$index] = '_0';
    }
  }

  // Discard values that are not in the current list of options.
  $values = array_values(array_intersect($values, array_keys($options)));
  return $values;
}

/**
 * Transforms submitted form values into field storage format.
 */
function _options_form_to_storage($element) {
  $values = array_values((array) $element['#value']);

  // On/off checkbox: transform '0 / 1' into the 'on / off' values.
  if ($element['#type'] == 'checkbox') {
    $values = array($values[0] ? $element['#on_value'] : $element['#off_value']);
  }

  // Substitute the '_0' placeholder.
  if (!empty($element['#zero_placeholder'])) {
    $index = array_search('_0', $values);
    if ($index !== FALSE) {
      $values[$index] = 0;
    }
  }

  // Filter out the 'none' option. Use a strict comparison, because
  // 0 == 'any string'.
  $index = array_search('_none', $values, TRUE);
  if ($index !== FALSE) {
    unset($values[$index]);
  }

  // Make sure we populate at least an empty value.
  if (empty($values)) {
    $values = array(NULL);
  }

  $result = options_array_transpose(array($element['#value_key'] => $values));
  return $result;
}

/**
 * Manipulates a 2D array to reverse rows and columns.
 *
 * The default data storage for fields is delta first, column names second.
 * This is sometimes inconvenient for field modules, so this function can be
 * used to present the data in an alternate format.
 *
 * @param $array
 *   The array to be transposed. It must be at least two-dimensional, and
 *   the subarrays must all have the same keys or behavior is undefined.
 * @return
 *   The transposed array.
 */
function options_array_transpose($array) {
  $result = array();
  if (is_array($array)) {
    foreach ($array as $key1 => $value1) {
      if (is_array($value1)) {
        foreach ($value1 as $key2 => $value2) {
          if (!isset($result[$key2])) {
            $result[$key2] = array();
          }
          $result[$key2][$key1] = $value2;
        }
      }
    }
  }
  return $result;
}

/**
 * Implements hook_field_widget_error().
 */
function options_field_widget_error($element, $error) {
  form_error($element, $error['message']);
}

/**
 *  Theme the label for the empty value for options that are not required.
 *  The default theme will display N/A for a radio list and blank for a select.
 */
function theme_options_none($variables) {
  $instance = $variables['instance'];
  switch ($instance['widget']['type']) {
    case 'options_buttons':
      return t('N/A');
    case 'options_select':
      return t('- None -');
    default :
      return '';
  }
}