<?php

/**

 * @file

 * Default 'implementations' of hook_field_*(): common field housekeeping.

 *

 * Those implementations are special, as field.module does not define any field

 * types. Those functions take care of default stuff common to all field types.

 * They are called through the _field_invoke_default() iterator, generally in

 * the corresponding field_attach_[operation]() function.

 */

/**

 * Extracts field values from submitted form values.

 *

 * @param $entity_type

 *   The type of $entity.

 * @param $entity

 *   The entity for the operation.

 * @param $field

 *   The field structure for the operation.

 * @param $instance

 *   The instance structure for $field on $entity's bundle.

 * @param $langcode

 *   The language associated to $items.

 * @param $items

 *   The field values. This parameter is altered by reference to receive the

 *   incoming form values.

 * @param $form

 *   The form structure where field elements are attached to. This might be a

 *   full form structure, or a sub-element of a larger form.

 * @param $form_state

 *   The form state.

 */

function field_default_extract_form_values($entity_type, $entity, $field, $instance, $langcode, &$items, $form, &$form_state) {

  $path = array_merge($form['#parents'], array($field['field_name'], $langcode));

  $key_exists = NULL;

  $values = drupal_array_get_nested_value($form_state['values'], $path, $key_exists);

  if ($key_exists) {

    // Remove the 'value' of the 'add more' button.

    unset($values['add_more']);

    $items = $values;

  }

}

/**

 * Generic field validation handler.

 *

 * Possible error codes:

 * - 'field_cardinality': The number of values exceeds the field cardinality.

 *

 * @see _hook_field_validate()

 *

 * @param $entity_type

 *   The type of $entity.

 * @param $entity

 *   The entity for the operation.

 * @param $field

 *   The field structure for the operation.

 * @param $instance

 *   The instance structure for $field on $entity's bundle.

 * @param $langcode

 *   The language associated to $items.

 * @param $items

 *   $entity->{$field['field_name']}[$langcode], or an empty array if unset.

 * @param $errors

 *   The array of errors, keyed by field name and by value delta, that have

 *   already been reported for the entity. The function should add its errors

 *   to this array. Each error is an associative array, with the following

 *   keys and values:

 *   - 'error': an error code (should be a string, prefixed with the module name)

 *   - 'message': the human readable message to be displayed.

 */

function field_default_validate($entity_type, $entity, $field, $instance, $langcode, $items, &$errors) {

  // Filter out empty values.

  $items = _field_filter_items($field, $items);

  // Check that the number of values doesn't exceed the field cardinality.

  // For form submitted values, this can only happen with 'multiple value'

  // widgets.

  if ($field['cardinality'] != FIELD_CARDINALITY_UNLIMITED && count($items) > $field['cardinality']) {

    $errors[$field['field_name']][$langcode][0][] = array(

      'error' => 'field_cardinality',

      'message' => t('%name: this field cannot hold more than @count values.', array('%name' => $instance['label'], '@count' => $field['cardinality'])),

    );

  }

}

function field_default_submit($entity_type, $entity, $field, $instance, $langcode, &$items, $form, &$form_state) {

  // Filter out empty values.

  $items = _field_filter_items($field, $items);

  // Reorder items to account for drag-n-drop reordering.

  $items = _field_sort_items($field, $items);

}

/**

 * Default field 'insert' operation.

 *

 * Insert default value if no $entity->$field_name entry was provided.

 * This can happen with programmatic saves, or on form-based creation where

 * the current user doesn't have 'edit' permission for the field.

 */

function field_default_insert($entity_type, $entity, $field, $instance, $langcode, &$items) {

  // _field_invoke() populates $items with an empty array if the $entity has no

  // entry for the field, so we check on the $entity itself.

  // We also check that the current field translation is actually defined before

  // assigning it a default value. This way we ensure that only the intended

  // languages get a default value. Otherwise we could have default values for

  // not yet open languages.

  if (empty($entity) || !property_exists($entity, $field['field_name']) ||

    (isset($entity->{$field['field_name']}[$langcode]) && count($entity->{$field['field_name']}[$langcode]) == 0)) {

    $items = field_get_default_value($entity_type, $entity, $field, $instance, $langcode);

  }

}

/**

 * Invokes hook_field_formatter_prepare_view() on the relevant formatters.

 *

 * @param $entity_type

 *   The type of $entity; e.g. 'node' or 'user'.

 * @param $entities

 *   An array of entities being displayed, keyed by entity id.

 * @param $field

 *   The field structure for the operation.

 * @param $instances

 *   Array of instance structures for $field for each entity, keyed by entity

 *   id.

 * @param $langcode

 *   The language associated to $items.

 * @param $items

 *   Array of field values already loaded for the entities, keyed by entity id.

 * @param $display

 *   Can be either:

 *   - the name of a view mode

 *   - or an array of display settings to use for display, as found in the

 *     'display' entry of $instance definitions.

 */

function field_default_prepare_view($entity_type, $entities, $field, $instances, $langcode, &$items, $display) {

  // Group entities, instances and items by formatter module.

  $modules = array();

  foreach ($instances as $id => $instance) {

    if (is_string($display)) {

      $view_mode = $display;

      $instance_display = field_get_display($instance, $view_mode, $entities[$id]);

    }

    else {

      $instance_display = $display;

    }

    if ($instance_display['type'] !== 'hidden') {

      $module = $instance_display['module'];

      $modules[$module] = $module;

      $grouped_entities[$module][$id] = $entities[$id];

      $grouped_instances[$module][$id] = $instance;

      $grouped_displays[$module][$id] = $instance_display;

      // hook_field_formatter_prepare_view() alters $items by reference.

      $grouped_items[$module][$id] = &$items[$id];

    }

  }

  foreach ($modules as $module) {

    // Invoke hook_field_formatter_prepare_view().

    $function = $module . '_field_formatter_prepare_view';

    if (function_exists($function)) {

      $function($entity_type, $grouped_entities[$module], $field, $grouped_instances[$module], $langcode, $grouped_items[$module], $grouped_displays[$module]);

    }

  }

}

/**

 * Builds a renderable array for one field on one entity instance.

 *

 * @param $entity_type

 *   The type of $entity; e.g. 'node' or 'user'.

 * @param $entity

 *   A single object of type $entity_type.

 * @param $field

 *   The field structure for the operation.

 * @param $instance

 *   An array containing each field on $entity's bundle.

 * @param $langcode

 *   The language associated to $items.

 * @param $items

 *   Array of field values already loaded for the entities, keyed by entity id.

 * @param $display

 *   Can be either:

 *   - the name of a view mode;

 *   - or an array of custom display settings, as found in the 'display' entry

 *     of $instance definitions.

 */

function field_default_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {

  list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);

  $addition = array();

  // Prepare incoming display specifications.

  if (is_string($display)) {

    $view_mode = $display;

    $display = field_get_display($instance, $view_mode, $entity);

  }

  else {

    $view_mode = '_custom_display';

  }

  if ($display['type'] !== 'hidden') {

    // Calling the formatter function through module_invoke() can have a

    // performance impact on pages with many fields and values.

    $function = $display['module'] . '_field_formatter_view';

    if (function_exists($function)) {

      $elements = $function($entity_type, $entity, $field, $instance, $langcode, $items, $display);

      if ($elements) {

        $info = array(

          '#theme' => 'field',

          '#weight' => $display['weight'],

          '#title' => $instance['label'],

          '#access' => field_access('view', $field, $entity_type, $entity),

          '#label_display' => $display['label'],

          '#view_mode' => $view_mode,

          '#language' => $langcode,

          '#field_name' => $field['field_name'],

          '#field_type' => $field['type'],

          '#field_translatable' => $field['translatable'],

          '#entity_type' => $entity_type,

          '#bundle' => $bundle,

          '#object' => $entity,

          '#items' => $items,

          '#formatter' => $display['type']

        );

        $addition[$field['field_name']] = array_merge($info, $elements);

      }

    }

  }

  return $addition;

}

/**

 * Copies source field values into the entity to be prepared.

 *

 * @param $entity_type

 *   The type of $entity; e.g. 'node' or 'user'.

 * @param $entity

 *   The entity to be prepared for translation.

 * @param $field

 *   The field structure for the operation.

 * @param $instance

 *   The instance structure for $field on $entity's bundle.

 * @param $langcode

 *   The language the entity has to be translated in.

 * @param $items

 *   $entity->{$field['field_name']}[$langcode], or an empty array if unset.

 * @param $source_entity

 *   The source entity holding the field values to be translated.

 * @param $source_langcode

 *   The source language from which translate.

 */

function field_default_prepare_translation($entity_type, $entity, $field, $instance, $langcode, &$items, $source_entity, $source_langcode) {

  $field_name = $field['field_name'];

  // If the field is untranslatable keep using LANGUAGE_NONE.

  if ($langcode == LANGUAGE_NONE) {

    $source_langcode = LANGUAGE_NONE;

  }

  if (isset($source_entity->{$field_name}[$source_langcode])) {

    $items = $source_entity->{$field_name}[$source_langcode];

  }

}