Club Drupal

<?php

/**

 * @file

 * Provides various callbacks for the whole core module integration.

 */

/**

 * Callback for getting properties of an entity.

 */

function entity_metadata_entity_get_properties($entity, array $options, $name, $entity_type) {

  if ($name == 'url') {

    $return = entity_uri($entity_type, $entity);

    return url($return['path'], $return['options'] + $options);

  }

}

/**

 * Callback for getting book node properties.

 * @see entity_metadata_book_entity_info_alter()

 */

function entity_metadata_book_get_properties($node, array $options, $name, $entity_type) {

  switch ($name) {

    case 'book':

      if (isset($node->book['bid'])) {

        return $node->book['bid'];

      }

      return NULL;

    case 'book_ancestors':

      $ancestors = array();

      while (!empty($node->book['plid']) && $node->book['plid'] != -1) {

        $link = book_link_load($node->book['plid']);

        array_unshift($ancestors, $link['nid']);

        $node = node_load($link['nid']);

      }

      return $ancestors;

  }

}

/**

 * Callback for getting comment properties.

 * @see entity_metadata_comment_entity_info_alter()

 */

function entity_metadata_comment_get_properties($comment, array $options, $name) {

  switch ($name) {

    case 'name':

      return $comment->name;

    case 'mail':

      if ($comment->uid != 0) {

        $account = user_load($comment->uid);

        return $account->mail;

      }

      return $comment->mail;

    case 'edit_url':

      return url('comment/edit/' . $comment->cid, $options);

    case 'parent':

      if (!empty($comment->pid)) {

        return $comment->pid;

      }

      // There is no parent comment.

      return NULL;

  }

}

/**

 * Callback for setting comment properties.

 * @see entity_metadata_comment_entity_info_alter()

 */

function entity_metadata_comment_setter($comment, $name, $value) {

  switch ($name) {

    case 'node':

      $comment->nid = $value;

      // Also set the bundle name.

      $node = node_load($value);

      $comment->node_type = 'comment_node_' . $node->type;

      break;

  }

}

/**

 * Callback for getting comment related node properties.

 * @see entity_metadata_comment_entity_info_alter()

 */

function entity_metadata_comment_get_node_properties($node, array $options, $name, $entity_type) {

  switch ($name) {

    case 'comment_count':

      return isset($node->comment_count) ? $node->comment_count : 0;

    case 'comment_count_new':

      return comment_num_new($node->nid);

    case 'comments':

      $select = db_select('comment', 'c')

        ->fields('c', array('cid'))

        ->condition('c.nid', $node->nid);

      return array_keys($select->execute()->fetchAllKeyed(0, 0));

  }

}

/**

 * Getter callback for getting global languages.

 */

function entity_metadata_locale_get_languages($data, array $options, $name) {

  return isset($GLOBALS[$name]) ? $GLOBALS[$name]->language : NULL;

}

/**

 * Getter callback for getting the preferred user language.

 */

function entity_metadata_locale_get_user_language($account, array $options, $name) {

  return user_preferred_language($account)->language;

}

/**

 * Return the options lists for the node and comment status property.

 */

function entity_metadata_status_options_list() {

  return array(

    NODE_PUBLISHED => t('Published'),

    NODE_NOT_PUBLISHED => t('Unpublished'),

  );

}

/**

 * Callback for getting node properties.

 *

 * @see entity_metadata_node_entity_info_alter()

 */

function entity_metadata_node_get_properties($node, array $options, $name, $entity_type) {

  switch ($name) {

    case 'is_new':

      return empty($node->nid) || !empty($node->is_new);

    case 'source':

      if (!empty($node->tnid) && $source = node_load($node->tnid)) {

        return $source;

      }

      return NULL;

    case 'edit_url':

      return url('node/' . $node->nid . '/edit', $options);

    case 'author':

      return !empty($node->uid) ? $node->uid : drupal_anonymous_user();

  }

}

/**

 * Callback for determing access for node revision related properties.

 */

function entity_metadata_node_revision_access($op, $name, $entity = NULL, $account = NULL) {

  return $op == 'view' ? user_access('view revisions', $account) : user_access('administer nodes', $account);

}

/**

 * Callback for getting poll properties.

 * @see entity_metadata_poll_entity_info_alter()

 */

function entity_metadata_poll_node_get_properties($node, array $options, $name) {

  $total_votes = $highest_votes = 0;

  foreach ($node->choice as $choice) {

    if ($choice['chvotes'] > $highest_votes) {

      $winner = $choice;

      $highest_votes = $choice['chvotes'];

    }

    $total_votes = $total_votes + $choice['chvotes'];

  }

  if ($name == 'poll_duration') {

    return $node->runtime;

  }

  elseif ($name == 'poll_votes') {

    return $total_votes;

  }

  elseif (!isset($winner)) {

    // There is no poll winner yet.

    return NULL;

  }

  switch ($name) {

    case 'poll_winner_votes':

        return $winner['chvotes'];

    case 'poll_winner':

        return $winner['chtext'];

    case 'poll_winner_percent':

        return ($winner['chvotes'] / $total_votes) * 100;

  }

}

/**

 * Callback for getting statistics properties.

 * @see entity_metadata_statistics_entity_info_alter()

 */

function entity_metadata_statistics_node_get_properties($node, array $options, $name) {

  $statistics = (array) statistics_get($node->nid);

  $statistics += array('totalcount' => 0, 'daycount' => 0, 'timestamp' => NULL);

  switch ($name) {

    case 'views':

      return $statistics['totalcount'];

    case 'day_views':

      return $statistics['daycount'];

    case 'last_view':

      return $statistics['timestamp'];

  }

}

/**

 * Access callback for restricted node statistics properties.

 */

function entity_metadata_statistics_properties_access($op, $property, $entity = NULL, $account = NULL) {

  if ($property == 'views' && user_access('view post access counter', $account)) {

    return TRUE;

  }

  return user_access('access statistics', $account);

}

/**

 * Callback for getting site-wide properties.

 * @see entity_metadata_system_entity_info_alter()

 */

function entity_metadata_system_get_properties($data = FALSE, array $options, $name) {

  switch ($name) {

    case 'name':

      return variable_get('site_name', 'Drupal');

    case 'url':

      return url('<front>', $options);

    case 'login_url':

      return url('user', $options);

    case 'current_user':

      return $GLOBALS['user']->uid ? $GLOBALS['user']->uid : drupal_anonymous_user();

    case 'current_date':

      return REQUEST_TIME;

    case 'current_page':

      // Subsequent getters of the struct retrieve the actual values.

      return array();

    default:

      return variable_get('site_' . $name, '');

  }

}

/**

 * Callback for getting properties for the current page request.

 * @see entity_metadata_system_entity_info_alter()

 */

function entity_metadata_system_get_page_properties($data = array(), array $options, $name) {

  switch ($name) {

    case 'url':

      return $GLOBALS['base_root'] . request_uri();

  }

}

/**

 * Callback for getting file properties.

 * @see entity_metadata_system_entity_info_alter()

 */

function entity_metadata_system_get_file_properties($file, array $options, $name) {

  switch ($name) {

    case 'name':

      return $file->filename;

    case 'mime':

      return $file->filemime;

    case 'size':

      return $file->filesize;

    case 'url':

      return url(file_create_url($file->uri), $options);

    case 'owner':

      return $file->uid;

  }

}

/**

 * Callback for getting term properties.

 *

 * @see entity_metadata_taxonomy_entity_info_alter()

 */

function entity_metadata_taxonomy_term_get_properties($term, array $options, $name) {

  switch ($name) {

    case 'node_count':

      return count(taxonomy_select_nodes($term->tid));

    case 'description':

      return check_markup($term->description, isset($term->format) ? $term->format : NULL, '', TRUE);

    case 'parent':

      if (isset($term->parent[0]) && !is_array(isset($term->parent[0]))) {

        return $term->parent;

      }

      return array_keys(taxonomy_get_parents($term->tid));

    case 'parents_all':

      // We have to return an array of ids.

      $tids = array();

      foreach (taxonomy_get_parents_all($term->tid) as $parent) {

        $tids[] = $parent->tid;

      }

      return $tids;

  }

}

/**

 * Callback for setting term properties.

 *

 * @see entity_metadata_taxonomy_entity_info_alter()

 */

function entity_metadata_taxonomy_term_setter($term, $name, $value) {

  switch ($name) {

    case 'vocabulary':

      // Make sure to update the taxonomy bundle key, so load the vocabulary.

      // Support both, loading by name or ID.

      $vocabulary = is_numeric($value) ? taxonomy_vocabulary_load($value) : taxonomy_vocabulary_machine_name_load($value);

      $term->vocabulary_machine_name = $vocabulary->machine_name;

      return $term->vid = $vocabulary->vid;

    case 'parent':

      return $term->parent = $value;

  }

}

/**

 * Callback for getting vocabulary properties.

 * @see entity_metadata_taxonomy_entity_info_alter()

 */

function entity_metadata_taxonomy_vocabulary_get_properties($vocabulary, array $options, $name) {

  switch ($name) {

    case 'term_count':

      $sql = "SELECT COUNT (1) FROM {taxonomy_term_data} td WHERE td.vid = :vid";

      return db_query($sql, array(':vid' => $vocabulary->vid))->fetchField();

  }

}

/**

 * Callback for getting user properties.

 * @see entity_metadata_user_entity_info_alter()

 */

function entity_metadata_user_get_properties($account, array $options, $name, $entity_type) {

  switch ($name) {

    case 'last_access':

      // In case there was no access the value is 0, but we have to return NULL.

      return empty($account->access) ? NULL : $account->access;

    case 'last_login':

      return empty($account->login) ? NULL : $account->login;

    case 'name':

      return empty($account->uid) ? variable_get('anonymous', t('Anonymous')) : $account->name;

    case 'url':

      if (empty($account->uid)) {

        return NULL;

      }

      $return = entity_uri('user', $account);

      return $return ? url($return['path'], $return['options'] + $options) : '';

    case 'edit_url':

      return empty($account->uid) ? NULL : url("user/$account->uid/edit", $options);

    case 'roles':

      return isset($account->roles) ? array_keys($account->roles) : array();

    case 'theme':

      return empty($account->theme) ? variable_get('theme_default', 'bartik') : $account->theme;

  }

}

/**

 * Callback for setting user properties.

 * @see entity_metadata_user_entity_info_alter()

 */

function entity_metadata_user_set_properties($account, $name, $value) {

  switch ($name) {

    case 'roles':

      $account->roles = array_intersect_key(user_roles(), array_flip($value));

      break;

  }

}

/**

 * Options list callback returning all user roles.

 */

function entity_metadata_user_roles($property_name = 'roles', $info = array(), $op = 'edit') {

  $roles = user_roles();

  if ($op == 'edit') {

    unset($roles[DRUPAL_AUTHENTICATED_RID], $roles[DRUPAL_ANONYMOUS_RID]);

  }

  return $roles;

}

/**

 * Return the options lists for user status property.

 */

function entity_metadata_user_status_options_list() {

  return array(

    0 => t('Blocked'),

    1 => t('Active'),

  );

}

/**

 * Callback defining an options list for language properties.

 */

function entity_metadata_language_list() {

  $list = array();

  $list[LANGUAGE_NONE] = t('Language neutral');

  foreach (language_list() as $language) {

    $list[$language->language] = t($language->name);

  }

  return $list;

}

/**

 * Callback for getting field property values.

 */

function entity_metadata_field_property_get($entity, array $options, $name, $entity_type, $info) {

  $field = field_info_field($name);

  $columns = array_keys($field['columns']);

  $langcode = isset($options['language']) ? $options['language']->language : LANGUAGE_NONE;

  $langcode = entity_metadata_field_get_language($entity_type, $entity, $field, $langcode, TRUE);

  $values = array();

  if (isset($entity->{$name}[$langcode])) {

    foreach ($entity->{$name}[$langcode] as $delta => $data) {

      $values[$delta] = $data[$columns[0]];

      if ($info['type'] == 'boolean' || $info['type'] == 'list<boolean>') {

        // Ensure that we have a clean boolean data type.

        $values[$delta] = (boolean) $values[$delta];

      }

    }

  }

  // For an empty single-valued field, we have to return NULL.

  return $field['cardinality'] == 1 ? ($values ? reset($values) : NULL) : $values;

}

/**

 * Callback for setting field property values.

 */

function entity_metadata_field_property_set($entity, $name, $value, $langcode, $entity_type, $info) {

  $field = field_info_field($name);

  $columns = array_keys($field['columns']);

  $langcode = entity_metadata_field_get_language($entity_type, $entity, $field, $langcode);

  $values = $field['cardinality'] == 1 ? array($value) : (array) $value;

  $items = array();

  foreach ($values as $delta => $value) {

    if (isset($value)) {

      $items[$delta][$columns[0]] = $value;

      if ($info['type'] == 'boolean' || $info['type'] == 'list<boolean>') {

        // Convert boolean values back to an integer for writing.

        $items[$delta][$columns[0]] = (integer) $items[$delta][$columns[0]] = $value;

      }

    }

  }

  $entity->{$name}[$langcode] = $items;

  // Empty the static field language cache, so the field system picks up any

  // possible new languages.

  drupal_static_reset('field_language');

}

/**

 * Callback returning the options list of a field.

 */

function entity_metadata_field_options_list($name, $info) {

  $field_property_info = $info;

  if (is_numeric($name) && isset($info['parent'])) {

    // The options list is to be returned for a single item of a multiple field.

    $field_property_info = $info['parent']->info();

    $name = $field_property_info['name'];

  }

  if (($field = field_info_field($name)) && isset($field_property_info['parent'])) {

    // Retrieve the wrapped entity holding the field.

    $wrapper = $field_property_info['parent'];

    try {

      $entity = $wrapper->value();

    }

    catch (EntityMetadataWrapperException $e) {

      // No data available.

      $entity = NULL;

    }

    // Support translating labels via i18n field.

    if (module_exists('i18n_field') && ($translate = i18n_field_type_info($field['type'], 'translate_options'))) {

      return $translate($field);

    }

    else {

      $instance = $wrapper->getBundle() ? field_info_instance($wrapper->type(), $name, $wrapper->getBundle()) : NULL;

      return (array) module_invoke($field['module'], 'options_list', $field, $instance, $wrapper->type(), $entity);

    }

  }

}

/**

 * Callback to verbatim get the data structure of a field. Useful for fields

 * that add metadata for their own data structure.

 */

function entity_metadata_field_verbatim_get($entity, array $options, $name, $entity_type, &$context) {

  // Set contextual info useful for getters of any child properties.

  $context['instance'] = field_info_instance($context['parent']->type(), $name, $context['parent']->getBundle());

  $context['field'] = field_info_field($name);

  $langcode = isset($options['language']) ? $options['language']->language : LANGUAGE_NONE;

  $langcode = entity_metadata_field_get_language($entity_type, $entity, $context['field'], $langcode, TRUE);

  if ($context['field']['cardinality'] == 1) {

    return isset($entity->{$name}[$langcode][0]) ? $entity->{$name}[$langcode][0] : NULL;

  }

  return isset($entity->{$name}[$langcode]) ? $entity->{$name}[$langcode] : array();

}

/**

 * Writes the passed field items in the object. Useful as field level setter

 * to set the whole data structure at once.

 */

function entity_metadata_field_verbatim_set($entity, $name, $items, $langcode, $entity_type) {

  $field = field_info_field($name);

  $langcode = entity_metadata_field_get_language($entity_type, $entity, $field, $langcode);

  $value = $field['cardinality'] == 1 ? array($items) : (array) $items;

  // Filter out any items set to NULL.

  $entity->{$name}[$langcode] = array_filter($value);

  // Empty the static field language cache, so the field system picks up any

  // possible new languages.

  drupal_static_reset('field_language');

}

/**

 * Helper for determining the field language to be used.

 *

 * Note that we cannot use field_language() as we are not about to display

 * values, but generally read/write values.

 *

 * @param $fallback

 *   (optional) Whether to fall back to the entity default language, if no

 *   value is available for the given language code yet.

 *

 * @return

 *   The language code to use.

 */

function entity_metadata_field_get_language($entity_type, $entity, $field, $langcode = LANGUAGE_NONE, $fallback = FALSE) {

  // Try to figure out the default language used by the entity.

  // With Drupal >= 7.15 we can use entity_language().

  if (function_exists('entity_language')) {

    $default_langcode = entity_language($entity_type, $entity);

  }

  else {

    $default_langcode = !empty($entity->language) ? $entity->language : LANGUAGE_NONE;

  }

  // Determine the right language to use.

  if ($default_langcode != LANGUAGE_NONE && field_is_translatable($entity_type, $field)) {

    $langcode = ($langcode != LANGUAGE_NONE) ? field_valid_language($langcode, $default_langcode) : $default_langcode;

    if (!isset($entity->{$field['field_name']}[$langcode]) && $fallback) {

      $langcode = $default_langcode;

    }

    return $langcode;

  }

  else {

    return LANGUAGE_NONE;

  }

}

/**

 * Callback for getting the sanitized text of 'text_formatted' properties.

 * This callback is used for both the 'value' and the 'summary'.

 */

function entity_metadata_field_text_get($item, array $options, $name, $type, $context) {

  // $name is either 'value' or 'summary'.

  if (!isset($item['safe_' . $name])) {

    // Apply input formats.

    $langcode = isset($options['language']) ? $options['language']->language : '';

    $format = isset($item['format']) ? $item['format'] : filter_default_format();

    $item['safe_' . $name] = check_markup($item[$name], $format, $langcode);

    // To speed up subsequent calls, update $item with the 'safe_value'.

    $context['parent']->set($item);

  }

  return $item['safe_' . $name];

}

/**

 * Defines the list of all available text formats.

 */

function entity_metadata_field_text_formats() {

  foreach (filter_formats() as $key => $format) {

    $formats[$key] = $format->name;

  }

  return $formats;

}

/**

 * Callback for getting the file entity of file fields.

 */

function entity_metadata_field_file_get($item) {

  return $item['fid'];

}

/**

 * Callback for setting the file entity of file fields.

 */

function entity_metadata_field_file_set(&$item, $property_name, $value) {

  $item['fid'] = $value;

}

/**

 * Callback for auto-creating file field $items.

 */

function entity_metadata_field_file_create_item($property_name, $context) {

  // 'fid' is required, so 'file' has to be set as initial property.

  return array('display' => isset($context['field']['settings']['display_default']) ? $context['field']['settings']['display_default'] : 0);

}

/**

 * Callback for validating file field $items.

 */

function entity_metadata_field_file_validate_item($items, $context) {

  // Allow NULL values.

  if (!isset($items)) {

    return TRUE;

  }

  // Stream-line $items for multiple vs non-multiple fields.

  $items = !entity_property_list_extract_type($context['type']) ? array($items) : (array) $items;

  foreach ($items as $item) {

    // File-field items require a valid file.

    if (!isset($item['fid']) || !file_load($item['fid'])) {

      return FALSE;

    }

    if (isset($context['property info']['display']) && !isset($item['display'])) {

      return FALSE;

    }

  }

  return TRUE;

}

/**

 * Access callback for the node entity.

 *

 * This function does not implement hook_node_access(), thus it may not be

 * called entity_metadata_node_access().

 *

 * @see entity_access()

 *

 * @param $op

 *   The operation being performed. One of 'view', 'update', 'create' or

 *   'delete'.

 * @param $node

 *   A node to check access for. Must be a node object. Must have nid,

 *   except in the case of 'create' operations.

 * @param $account

 *   The user to check for. Leave it to NULL to check for the global user.

 *

 * @throws EntityMalformedException

 *

 * @return boolean

 *   TRUE if access is allowed, FALSE otherwise.

 */

function entity_metadata_no_hook_node_access($op, $node = NULL, $account = NULL) {

  // First deal with the case where a $node is provided.

  if (isset($node)) {

    if (empty($node->vid) && in_array($op, array('create', 'update'))) {

      // This is a new node or the original node.

      if (isset($node->type)) {

        $op = empty($node->nid) || !empty($node->is_new) ? 'create' : 'update';

        return node_access($op, $op == 'create' ? $node->type : $node, $account);

      }

      else {

        throw new EntityMalformedException('Permission to create a node was requested but no node type was given.');

      }

    }

    // If a non-default revision is given, incorporate revision access.

    $default_revision = node_load($node->nid);

    if ($node->vid !== $default_revision->vid) {

      return _node_revision_access($node, $op, $account);

    }

    else {

      return node_access($op, $node, $account);

    }

  }

  // No node is provided. Check for access to all nodes.

  if (user_access('bypass node access', $account)) {

    return TRUE;

  }

  if (!user_access('access content', $account)) {

    return FALSE;

  }

  if ($op == 'view' && node_access_view_all_nodes($account)) {

    return TRUE;

  }

  return FALSE;

}

/**

 * Access callback for the user entity.

 */

function entity_metadata_user_access($op, $entity = NULL, $account = NULL, $entity_type = NULL) {

  $account = isset($account) ? $account : $GLOBALS['user'];

  // Grant access to the users own user account and to the anonymous one.

  if (isset($entity->uid) && $op != 'delete' && (($entity->uid == $account->uid && $entity->uid) || (!$entity->uid && $op == 'view'))) {

    return TRUE;

  }

  if (user_access('administer users', $account)

    || user_access('access user profiles', $account) && $op == 'view' && (empty($entity) || !empty($entity->status))) {

    return TRUE;

  }

  return FALSE;

}

/**

 * Access callback for restricted user properties.

 */

function entity_metadata_user_properties_access($op, $property, $entity = NULL, $account = NULL) {

  if (user_access('administer users', $account)) {

    return TRUE;

  }

  $account = isset($account) ? $account : $GLOBALS['user'];

  // Flag to indicate if this user entity is the own user account.

  $is_own_account = isset($entity->uid) && $account->uid == $entity->uid;

  switch ($property) {

    case 'name':

      // Allow view access to anyone with access to the entity.

      if ($op == 'view') {

        return TRUE;

      }

      // Allow edit access for own user name if the permission is satisfied.

      return $is_own_account && user_access('change own username', $account);

    case 'mail':

      // Allow access to own mail address.

      return $is_own_account;

    case 'roles':

      // Allow view access for own roles.

      return ($op == 'view' && $is_own_account);

  }

  return FALSE;

}

/**

 * Access callback for the comment entity.

 */

function entity_metadata_comment_access($op, $entity = NULL, $account = NULL) {

  // When determining access to a comment, 'comment_access' does not take any

  // access restrictions to the comment's associated node into account. If a

  // comment has an associated node, the user must be able to view it in order

  // to access the comment.

  if (isset($entity->nid)) {

    if (!entity_access('view', 'node', node_load($entity->nid), $account)) {

      return FALSE;

    }

  }

  // Comment administrators are allowed to perform all operations on all

  // comments.

  if (user_access('administer comments', $account)) {

    return TRUE;

  }

  // Unpublished comments can never be accessed by non-admins.

  if (isset($entity->status) && $entity->status == COMMENT_NOT_PUBLISHED) {

    return FALSE;

  }

  if (isset($entity) && $op == 'update') {

    // Because 'comment_access' only checks the current user, we need to do our

    // own access checking if an account was specified.

    if (!isset($account)) {

      return comment_access('edit', $entity);

    }

    else {

      return $account->uid && $account->uid == $entity->uid && user_access('edit own comments', $account);

    }

  }

  if (user_access('access comments', $account) && $op == 'view') {

    return TRUE;

  }

  return FALSE;

}

/**

 * Access callback for restricted comment properties.

 */

function entity_metadata_comment_properties_access($op, $property, $entity = NULL, $account = NULL) {

  return user_access('administer comments', $account);

}

/**

 * Access callback for the taxonomy entities.

 */

function entity_metadata_taxonomy_access($op, $entity = NULL, $account = NULL, $entity_type = NULL) {

  // If user has administer taxonomy permission then no further checks.

  if (user_access('administer taxonomy', $account)) {

    return TRUE;

  }

  switch ($op) {

    case "view":

      if (user_access('access content', $account)) {

        return TRUE;

      }

      break;

    case "update":

      if ($entity_type == 'taxonomy_term') {

        return user_access("edit terms in $entity->vid", $account);

      }

      break;

    case "create":

      if ($entity_type == 'taxonomy_term') {

        // Check for taxonomy_access_fix contrib module which adds additional

        // permissions to create new terms in a given vocabulary.

        if (function_exists('taxonomy_access_fix_access')) {

          return taxonomy_access_fix_access('add terms', $entity->vocabulary_machine_name);

        }

      }

      break;

    case "delete":

      if ($entity_type == 'taxonomy_term') {

        return user_access("delete terms in $entity->vid", $account);

      }

      break;

  }

  return FALSE;

}

/**

 * Access callback for file entities.

 */

function entity_metadata_file_access($op, $file = NULL, $account = NULL, $entity_type) {

  // We can only check access for the current user, so return FALSE on other accounts.

  global $user;

  if ($op == 'view' && isset($file) && (!isset($account) || $user->uid == $account->uid)) {

    // Invoke hook_file_download() to obtain access information.

    foreach (module_implements('file_download') as $module) {

      $result = module_invoke($module, 'file_download', $file->uri);

      if ($result == -1) {

        return FALSE;

      }

    }

    return TRUE;

  }

  return FALSE;

}

/**

 * Callback to determine access for properties which are fields.

 */

function entity_metadata_field_access_callback($op, $name, $entity = NULL, $account = NULL, $entity_type) {

  $field = field_info_field($name);

  return field_access($op, $field, $entity_type, $entity, $account);

}

/**

 * Callback to create entity objects.

 */

function entity_metadata_create_object($values = array(), $entity_type) {

  $info = entity_get_info($entity_type);

  // Make sure at least the bundle and label properties are set.

  if (isset($info['entity keys']['bundle']) && $key = $info['entity keys']['bundle']) {

    $values += array($key => NULL);

  }

  if (isset($info['entity keys']['label']) && $key = $info['entity keys']['label']) {

    $values += array($key => NULL);

  }

  $entity = (object) $values;

  $entity->is_new = TRUE;

  return $entity;

}

/**

 * Callback to create a new comment.

 */

function entity_metadata_create_comment($values = array()) {

  $comment = (object) ($values + array(

    'status' => COMMENT_PUBLISHED,

    'pid' => 0,

    'subject' => '',

    'uid' => 0,

    'language' => LANGUAGE_NONE,

    'node_type' => NULL,

    'is_new' => TRUE,

  ));

  $comment->cid = FALSE;

  return $comment;

}

/**

 * Callback to create a new node.

 */

function entity_metadata_create_node($values = array()) {

  $node = (object) array(

    'type' => $values['type'],

    'language' => LANGUAGE_NONE,

    'is_new' => TRUE,

  );

  // Set some defaults.

  $node_options = variable_get('node_options_' . $node->type, array('status', 'promote'));

  foreach (array('status', 'promote', 'sticky') as $key) {

    $node->$key = (int) in_array($key, $node_options);

  }

  if (module_exists('comment') && !isset($node->comment)) {

    $node->comment = variable_get("comment_$node->type", COMMENT_NODE_OPEN);

  }

  // Apply the given values.

  foreach ($values as $key => $value) {

    $node->$key = $value;

  }

  return $node;

}

/**

 * Callback to save a user account.

 */

function entity_metadata_user_save($account) {

  $edit = (array) $account;

  // Don't save the hashed password as password.

  unset($edit['pass']);

  user_save($account, $edit);

}

/**

 * Callback to delete a file.

 * Watch out to not accidentilly implement hook_file_delete().

 */

function entity_metadata_delete_file($fid) {

  file_delete(file_load($fid), TRUE);

}

/**

 * Callback to view nodes.

 */

function entity_metadata_view_node($entities, $view_mode = 'full', $langcode = NULL) {

  $result = node_view_multiple($entities, $view_mode, 0, $langcode);

  // Make sure to key the result with 'node' instead of 'nodes'.

  return array('node' => reset($result));

}

/**

 * Callback to view comments.

 */

function entity_metadata_view_comment($entities, $view_mode = 'full', $langcode = NULL) {

  $build = array();

  $nodes = array();

  // The comments, indexed by nid and then by cid.

  $nid_comments = array();

  foreach ($entities as $cid => $comment) {

    $nid = $comment->nid;

    $nodes[$nid] = $nid;

    $nid_comments[$nid][$cid] = $comment;

  }

  $nodes = node_load_multiple(array_keys($nodes));

  foreach ($nid_comments as $nid => $comments) {

    $node = isset($nodes[$nid]) ? $nodes[$nid] : NULL;

    $build += comment_view_multiple($comments, $node, $view_mode, 0, $langcode);

  }

  return array('comment' => $build);

}

/**

 * Callback to view an entity, for which just ENTITYTYPE_view() is available.

 */

function entity_metadata_view_single($entities, $view_mode = 'full', $langcode = NULL, $entity_type) {

  $function = $entity_type . '_view';

  $build = array();

  foreach ($entities as $key => $entity) {

    $build[$entity_type][$key] = $function($entity, $view_mode, $langcode);

  }

  return $build;

}

/**

 * Callback to get the form of a node.

 */

function entity_metadata_form_node($node) {

  // Pre-populate the form-state with the right form include.

  $form_state['build_info']['args'] = array($node);

  form_load_include($form_state, 'inc', 'node', 'node.pages');

  return drupal_build_form($node->type . '_node_form', $form_state);

}

/**

 * Callback to get the form of a comment.

 */

function entity_metadata_form_comment($comment) {

  if (!isset($comment->node_type)) {

    $node = node_load($comment->nid);

    $comment->node_type = 'comment_node_' . $node->type;

  }

  return drupal_get_form($comment->node_type . '_form', $comment);

}

/**

 * Callback to get the form of a user account.

 */

function entity_metadata_form_user($account) {

  // If $account->uid is set then we want a user edit form.

  // Otherwise we want the user register form.

  if (isset($account->uid)) {

    $form_id = 'user_profile_form';

    form_load_include($form_state, 'inc', 'user', 'user.pages');

  }

  else {

    $form_id = 'user_register_form';

  }

  $form_state['build_info']['args'] = array($account);

  return drupal_build_form($form_id, $form_state);

}

/**

 * Callback to get the form of a term.

 */

function entity_metadata_form_taxonomy_term($term) {

  // Pre-populate the form-state with the right form include.

  $form_state['build_info']['args'] = array($term);

  form_load_include($form_state, 'inc', 'taxonomy', 'taxonomy.admin');

  return drupal_build_form('taxonomy_form_term', $form_state);

}

/**

 * Callback to get the form of a vocabulary.

 */

function entity_metadata_form_taxonomy_vocabulary($vocab) {

  // Pre-populate the form-state with the right form include.

  $form_state['build_info']['args'] = array($vocab);

  form_load_include($form_state, 'inc', 'taxonomy', 'taxonomy.admin');

  return drupal_build_form('taxonomy_form_vocabulary', $form_state);

}

/**

 * Callback to get the form for entities using the entity API admin ui.

 */

function entity_metadata_form_entity_ui($entity, $entity_type) {

  $info = entity_get_info($entity_type);

  $form_state = form_state_defaults();

  // Add in the include file as the form API does else with the include file

  // specified for the active menu item.

  if (!empty($info['admin ui']['file'])) {

    $path = isset($info['admin ui']['file path']) ? $info['admin ui']['file path'] : drupal_get_path('module', $info['module']);

    $form_state['build_info']['files']['entity_ui'] = $path . '/' . $info['admin ui']['file'];

    // Also load the include file.

    if (file_exists($form_state['build_info']['files']['entity_ui'])) {

      require_once DRUPAL_ROOT . '/' . $form_state['build_info']['files']['entity_ui'];

    }

  }

  return entity_ui_get_form($entity_type, $entity, $op = 'edit', $form_state);

}

/**

 * Callback for querying entity properties having their values stored in the

 * entities main db table.

 */

function entity_metadata_table_query($entity_type, $property, $value, $limit) {

  $properties = entity_get_all_property_info($entity_type);

  $info = $properties[$property] + array('schema field' => $property);

  $query = new EntityFieldQuery();

  $query->entityCondition('entity_type', $entity_type, '=')

        ->propertyCondition($info['schema field'], $value, is_array($value) ? 'IN' : '=')

        ->range(0, $limit);

  $result = $query->execute();

  return !empty($result[$entity_type]) ? array_keys($result[$entity_type]) : array();

}

/**

 * Callback for querying entities by field values. This function just queries

 * for the value of the first specified column. Also it is only suitable for

 * fields that don't process the data, so it's stored the same way as returned.

 */

function entity_metadata_field_query($entity_type, $property, $value, $limit) {

  $query = new EntityFieldQuery();

  $field = field_info_field($property);

  $columns = array_keys($field['columns']);

  $query->entityCondition('entity_type', $entity_type, '=')

        ->fieldCondition($field, $columns[0], $value, is_array($value) ? 'IN' : '=')

        ->range(0, $limit);

  $result = $query->execute();

  return !empty($result[$entity_type]) ? array_keys($result[$entity_type]) : array();

}

/**

 * Implements entity_uri() callback for file entities.

 */

function entity_metadata_uri_file($file) {

  return array(

    'path' => file_create_url($file->uri),

  );

}