Club Drupal

<?php

/**

 * @file

 * The Flag module.

 */

define('FLAG_API_VERSION', 3);

define('FLAG_ADMIN_PATH', 'admin/structure/flags');

define('FLAG_ADMIN_PATH_START', 3);

/**

 * Implements hook_entity_info().

 */

function flag_entity_info() {

  $return = array(

    'flagging' => array(

      'label' => t('Flagging'),

      'controller class' => 'FlaggingController',

      'base table' => 'flagging',

      'fieldable' => TRUE,

      'entity keys' => array(

        'id' => 'flagging_id',

        'bundle' => 'flag_name',

      ),

      // The following tells Field UI how to extract the bundle name from a

      // $flag object when we're visiting ?q=admin/.../manage/%flag/fields.

      'bundle keys' => array(

        'bundle' => 'name',

      ),

      'bundles' => array(),

      // The following tells EntityAPI how to save flaggings, thus allowing use

      // of Entity metadata wrappers (if present).

      'save callback' => 'flagging_save',

      'creation callback' => 'flagging_create',

    ),

  );

  // Add bundle info but bypass flag_get_flags() as we cannot use it here, as

  // it calls entity_get_info().

  $result = db_query("SELECT name, title FROM {flag}");

  $flag_names = $result->fetchAllKeyed();

  foreach ($flag_names as $flag_name => $flag_title) {

    $return['flagging']['bundles'][$flag_name] = array(

      'label' => $flag_title,

      'admin' => array(

        'path' => FLAG_ADMIN_PATH . '/manage/%flag',

        'real path' => FLAG_ADMIN_PATH . '/manage/' . $flag_name,

        'bundle argument' => FLAG_ADMIN_PATH_START + 1,

        'access arguments' => array('administer flags'),

      ),

    );

  }

  return $return;

}

/**

 * Loads a flagging entity.

 *

 * @param $flagging_id

 *   The 'flagging_id' database serial column.

 * @param $reset

 *   Whether to reset the DrupalDefaultEntityController cache.

 *

 * @return

 *   The entity object, or FALSE if it can't be found.

 */

function flagging_load($flagging_id, $reset = FALSE) {

  // The flag machine name is loaded in by FlaggingController::buildQuery().

  $result = entity_load('flagging', array($flagging_id), array(), $reset);

  return reset($result);

}

/**

 * Entity API creation callback.

 *

 * Creates an unsaved flagging object for use with $flag->flag().

 *

 * @param $values

 *   An array of values as described by the entity's property info. Only

 *   'flag_name' or 'fid' must be specified, since $flag->flag() does the rest.

 *

 * @return

 *   An unsaved flagging object containing the property values.

 */

function flagging_create($values = array()) {

  $flagging = (object) array();

  if (!isset($values['flag_name'])) {

    if (isset($values['fid'])) {

      // Add flag_name, determined from fid.

      $flag = flag_get_flag(NULL, $values['fid']);

      $values['flag_name'] = $flag->name;

    }

  }

  // Apply the given values.

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

    $flagging->$key = $value;

  }

  return $flagging;

}

/**

 * Saves a flagging entity.

 *

 * For a new flagging, throws an exception is the flag action is not allowed for

 * the given combination of flag, entity, and user.

 *

 * @param $flagging

 *   The flagging entity. This may have either flag_name or the flag fid set,

 *   and may also omit the uid property to use the current user.

 *

 * @throws Exception

 */

function flagging_save($flagging) {

  // Get the flag, either way.

  if (isset($flagging->flag_name)) {

    $flag = flag_get_flag($flagging->flag_name);

  }

  else {

    $flag = flag_get_flag(NULL, $flagging->fid);

  }

  if (!$flag) {

    throw new Exception('Flag not found for flagging entity.');

  }

  // Fill in properties that may be omitted.

  $flagging->fid = $flag->fid;

  $flagging->flag_name = $flag->name;

  if (!empty($flagging->uid)) {

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

  }

  else {

    $account = NULL;

  }

  $result = $flag->flag('flag', $flagging->entity_id, $account, FALSE, $flagging);

  if (!$result) {

    throw new Exception('Flag action not allowed for given flagging entity properties.');

  }

}

// @todo: Implement flagging_view(). Not extremely useful. I already have it.

// @todo: When renaming a flag: Call field_attach_rename_bundle().

// @todo: When creating a flag: Call field_attach_create_bundle().

// @todo: When deleting a flag: Call field_attach_delete_bundle().

// @tood: Discuss: Should flag deleting call flag_reset_flag()? No.

// @todo: flag_reset_flag():

// - it should delete the flaggings.

// - (it has other issues; see http://drupal.org/node/894992.)

// - (is problematic: it might not be possible to delete all data in a single page request.)

// @todo: Discuss: Note that almost all functions/identifiers dealing with

// flaggings *aren't* prefixed by "flag_". For example:

//  - The menu argument is %flagging, not %flag_flagging.

//  - The entity type is "flagging", not "flag_flagging".

// On the one hand this succinct version is readable and nice. On the other hand, it isn't

// very "correct".

/**

 * Implements hook_entity_query_alter().

 *

 * Replaces bundle condition in EntityFieldQuery on flagging entities

 * with query condition on [name] field in [flag] table.

 *

 * @see flag_query_flagging_flag_names_alter()

 */

function flag_entity_query_alter(EntityFieldQuery $query) {

  $conditions = &$query->entityConditions;

  // Alter only flagging queries with bundle conditions.

  if (isset($conditions['entity_type']) && $conditions['entity_type']['value'] == 'flagging' && isset($conditions['bundle'])) {

    $query->addTag('flagging_flag_names'); // Add tag to alter query.

    // Make value and operator of the bundle condition accessible

    // in hook_query_TAG_alter.

    $query->addMetaData('flag_name_value', $conditions['bundle']['value']);

    $query->addMetaData('flag_name_operator', $conditions['bundle']['operator']);

    unset($conditions['bundle']);

  }

}

/**

 * Implements hook_query_TAG_alter() for flagging_flag_names tag.

 *

 * @see flag_entity_query_alter()

 */

function flag_query_flagging_flag_names_alter(QueryAlterableInterface $query) {

  // Get value and operator for bundle condition from meta data.

  $value = $query->getMetaData('flag_name_value');

  $operator = $query->getMetaData('flag_name_operator');

  // Join [flag] and [flagging] tables by [fid] and

  // apply bundle condition on [flag].[name] field.

  $query->join('flag', 'f', 'flagging.fid = f.fid');

  $query->condition('f.name', $value, $operator);

}

/**

 * Implements hook_menu().

 */

function flag_menu() {

  $items[FLAG_ADMIN_PATH] = array(

    'title' => 'Flags',

    'page callback' => 'flag_admin_page',

    'access callback' => 'user_access',

    'access arguments' => array('administer flags'),

    'description' => 'Configure flags for marking content with arbitrary information (such as <em>offensive</em> or <em>bookmarked</em>).',

    'file' => 'includes/flag.admin.inc',

    'type' => MENU_NORMAL_ITEM,

  );

  $items[FLAG_ADMIN_PATH . '/list'] = array(

    'title' => 'List',

    'type' => MENU_DEFAULT_LOCAL_TASK,

    'weight' => -10,

  );

  $items[FLAG_ADMIN_PATH . '/add'] = array(

    'title' => 'Add flag',

    'page callback' => 'flag_add_page',

    'access callback' => 'user_access',

    'access arguments' => array('administer flags'),

    'file' => 'includes/flag.admin.inc',

    'type' => MENU_LOCAL_ACTION,

    'weight' => 1,

  );

  $items[FLAG_ADMIN_PATH . '/import'] = array(

    'title' => 'Import',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('flag_import_form'),

    'access arguments' => array('use flag import'),

    'file' => 'includes/flag.export.inc',

    'type' => MENU_LOCAL_TASK,

    'weight' => 2,

  );

  $items[FLAG_ADMIN_PATH . '/export'] = array(

    'title' => 'Export',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('flag_export_form'),

    'access arguments' => array('administer flags'),

    'file' => 'includes/flag.export.inc',

    'type' => MENU_LOCAL_TASK,

    'weight' => 3,

  );

  $items[FLAG_ADMIN_PATH . '/manage/%flag'] = array(

    'load arguments' => array(TRUE), // Allow for disabled flags.

    'page callback' => 'drupal_get_form',

    'page arguments' => array('flag_form', FLAG_ADMIN_PATH_START + 1),

    'access callback' => 'user_access',

    'access arguments' => array('administer flags'),

    'file' => 'includes/flag.admin.inc',

    'type' => MENU_CALLBACK,

    // Make the flag title the default title for descendant menu items.

    'title callback' => '_flag_menu_title',

    'title arguments' => array(FLAG_ADMIN_PATH_START + 1),

  );

  $items[FLAG_ADMIN_PATH . '/manage/%flag/edit'] = array(

    'load arguments' => array(TRUE), // Allow for disabled flags.

    'title' => 'Edit flag',

    'type' => MENU_DEFAULT_LOCAL_TASK,

    'weight' => -10,

  );

  $items[FLAG_ADMIN_PATH . '/manage/%flag/export'] = array(

    'title' => 'Export',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('flag_export_form', FLAG_ADMIN_PATH_START + 1),

    'access arguments' => array('administer flags'),

    'file' => 'includes/flag.export.inc',

    'type' => MENU_LOCAL_TASK,

    'weight' => 20,

  );

  $items[FLAG_ADMIN_PATH . '/manage/%flag/delete'] = array(

    'title' => 'Delete flag',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('flag_delete_confirm', FLAG_ADMIN_PATH_START + 1),

    'access callback' => 'user_access',

    'access arguments' => array('administer flags'),

    'file' => 'includes/flag.admin.inc',

    'type' => MENU_CALLBACK,

  );

  $items[FLAG_ADMIN_PATH . '/manage/%flag/update'] = array(

    'load arguments' => array(TRUE), // Allow for disabled flags.

    'title' => 'Update',

    'page callback' => 'flag_update_page',

    'page arguments' => array(FLAG_ADMIN_PATH_START + 1),

    'access arguments' => array('administer flags'),

    'file' => 'includes/flag.export.inc',

    'type' => MENU_CALLBACK,

  );

  $items['flag/%/%flag/%'] = array(

    'title' => 'Flag',

    'page callback' => 'flag_page',

    'page arguments' => array(1, 2, 3),

    'access callback' => 'user_access',

    'access arguments' => array('access content'),

    'file' => 'includes/flag.pages.inc',

    'type' => MENU_CALLBACK,

  );

  $items['flag/confirm/%/%flag/%'] = array(

    'title' => 'Flag confirm',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('flag_confirm', 2, 3, 4),

    'access callback' => 'user_access',

    'access arguments' => array('access content'),

    'file' => 'includes/flag.pages.inc',

    'type' => MENU_CALLBACK,

  );

  return $items;

}

/**

 * Implements hook_admin_menu_map().

 */

function flag_admin_menu_map() {

  if (!user_access('administer flags')) {

    return;

  }

  $map = array();

  $map[FLAG_ADMIN_PATH . '/manage/%flag'] = array(

    'parent' => FLAG_ADMIN_PATH,

    'arguments' => array(

      array(

        '%flag' => array_keys(flag_get_flags()),

      ),

    ),

  );

  if (module_exists('field_ui')) {

    foreach (entity_get_info() as $obj_type => $info) {

      if ($obj_type == 'flagging') {

        foreach ($info['bundles'] as $bundle_name => $bundle_info) {

          if (isset($bundle_info['admin'])) {

            $fields = array();

            foreach (field_info_instances($obj_type, $bundle_name) as $field) {

              $fields[] = $field['field_name'];

            }

            $arguments = array(

              '%flag' => array($bundle_name),

              '%field_ui_menu' => $fields,

            );

            $path = $bundle_info['admin']['path'];

            $map["$path/fields/%field_ui_menu"]['parent'] = "$path/fields";

            $map["$path/fields/%field_ui_menu"]['arguments'][] = $arguments;

          }

        }

      }

    }

  }

  return $map;

}

/**

 * Menu loader for '%flag' arguments.

 *

 * @param $flag_name

 *   The machine name of the flag.

 * @param $include_disabled

 *   (optional) Whether to return a disabled flag too. Normally only enabled

 *   flags are returned. Some menu items operate on disabled flags and in this

 *   case you need to turn on this switch by doing:

 *   @code

 *   'load arguments' => array(TRUE)

 *   @endcode

 *   in your hook_menu().

 *

 * @return

 *   Either the flag object, or FALSE if none was found.

 */

function flag_load($flag_name, $include_disabled = FALSE) {

  if (($flag = flag_get_flag($flag_name))) {

    return $flag;

  }

  else {

    // No enabled flag was found. Search among the disabled ones.

    if ($include_disabled) {

      $default_flags = flag_get_default_flags(TRUE);

      if (isset($default_flags[$flag_name])) {

        return $default_flags[$flag_name];

      }

    }

  }

  // A menu loader has to return FALSE (not NULL) when no object is found.

  return FALSE;

}

/**

 * Menu title callback.

 */

function _flag_menu_title($flag) {

  // The following conditional it to handle a D7 bug (@todo: link).

  return $flag ? $flag->get_title() : '';

}

/**

 * Implements hook_help().

 */

function flag_help($path, $arg) {

  switch ($path) {

    case FLAG_ADMIN_PATH:

      $output = '<p>' . t('This page lists all the <em>flags</em> that are currently defined on this system.') . '</p>';

      return $output;

    case FLAG_ADMIN_PATH . '/add':

      $output = '<p>' . t('Select the type of flag to create. An individual flag can only affect one type of object. This cannot be changed once the flag is created.') . '</p>';

      return $output;

    case FLAG_ADMIN_PATH . '/manage/%/fields':

      // Get the existing link types that provide a flagging form.

      $link_types = flag_get_link_types();

      $form_link_types = array();

      foreach (flag_get_link_types() as $link_type) {

        if ($link_type['provides form']) {

          $form_link_types[] = '<em>' . $link_type['title'] . '</em>';

        }

      }

      // Get the flag for which we're managing fields.

      $flag = menu_get_object('flag', FLAG_ADMIN_PATH_START + 1);

      // Common text.

      $output  = '<p>' . t('Flags can have fields added to them. For example, a "Spam" flag could have a <em>Reason</em> field where a user could type in why he believes the item flagged is spam. A "Bookmarks" flag could have a <em>Folder</em> field into which a user could arrange her bookmarks.') . '</p>';

      $output .= '<p>' . t('On this page you can add fields to flags, delete them, and otherwise manage them.') . '</p>';

      // Three cases:

      if ($flag->link_type == 'form') {

        // Case 1: the current link type is the flagging form. Don't tell the

        // user anything extra, all is fine.

      }

      elseif ($link_types[$flag->link_type]['provides form']) {

        // Case 2: the current link type shows the form for creation of the

        // flagging, but it not the flagging form. Tell the user they can't edit

        // existing flagging fields.

        $output .= t("Field values may be edited when flaggings are created because this flag's link type shows a form for the flagging. However, to edit field values on existing flaggings, you will need to set your flag to use the <em>Flagging form</em> link type. This is provided by the <em><a href='!flagging-form-url'>Flagging Form</a></em> module.", array(

          '!flagging-form-url' => 'http://drupal.org/project/flagging_form',

        ));

        if (!module_exists('flagging_form')) {

          $output .= ' <span class="warning">'

            . t("You do not currently have this module enabled.")

            . '</span>';

        }

        $output .= '</p>';

      }

      else {

        // Case 3: the current link type does not allow access to the flagging

        // form. Tell the user they should change it.

        $output .= '<p class="warning">' . t("To allow users to enter values for fields you will need to <a href='!form-link-type-url'>set your flag</a> to use one of the following link types which allow users to access the flagging form: !link-types-list. (In case a form isn't used, the fields are assigned their default values.)", array(

          '!form-link-type-url' => url('admin/structure/flags/manage/' . $flag->name, array('fragment' => 'edit-link-type')),

          // The list of labels from link types. These are all defined in code

          // in hook_flag_link_type_info() and therefore safe to output raw.

          '!link-types-list' => implode(', ', $form_link_types),

        )) . '</p>';

        $output .= '<p>' . t("Additionally, to edit field values on existing flaggings, you will need to set your flag to use the Flagging form link type. This is provided by the <em><a href='!flagging-form-url'>Flagging Form</a></em> module.", array(

          '!flagging-form-url' => 'http://drupal.org/project/flagging_form',

        ));

        if (!module_exists('flagging_form')) {

          $output .= ' <span class="warning">'

            . t("You do not currently have this module enabled.")

            . '</span>';

        }

        $output .= '</p>';

      }

      return $output;

  }

}

/**

 * Implements hook_init().

 */

function flag_init() {

  module_load_include('inc', 'flag', 'includes/flag.actions');

}

/**

 * Implements hook_hook_info().

 */

function flag_hook_info() {

  $hooks['flag_type_info'] = array(

    'group' => 'flag',

  );

  $hooks['flag_type_info_alter'] = array(

    'group' => 'flag',

  );

  $hooks['flag_link_type_info'] = array(

    'group' => 'flag',

  );

  $hooks['flag_link_type_info_alter'] = array(

    'group' => 'flag',

  );

  return $hooks;

}

/**

 * Get a flag type definition.

 *

 * @param $entity_type

 *   (optional) The entity type to get the definition for, or NULL to return

 *   all flag types.

 *

 * @return

 *   The flag type definition array.

 *

 * @see hook_flag_type_info()

 */

function flag_fetch_definition($entity_type = NULL) {

  $definitions = &drupal_static(__FUNCTION__);

  if (!isset($definitions)) {

    if ($cache = cache_get('flag_type_info')) {

      $definitions = $cache->data;

    }

    else {

      $definitions = module_invoke_all('flag_type_info');

      drupal_alter('flag_type_info', $definitions);

      cache_set('flag_type_info', $definitions);

    }

  }

  if (isset($entity_type)) {

    if (isset($definitions[$entity_type])) {

      return $definitions[$entity_type];

    }

  }

  else {

    return $definitions;

  }

}

/**

 * Returns all flag types defined on the system.

 *

 * @return

 *   An array of flag type names.

 */

function flag_get_types() {

  $types = &drupal_static(__FUNCTION__);

  if (!isset($types)) {

    $types = array_keys(flag_fetch_definition());

  }

  return $types;

}

/**

 * Instantiates a new flag handler.

 *

 * A flag handler is more commonly know as "a flag". A factory method usually

 * populates this empty flag with settings loaded from the database.

 *

 * @param $entity_type

 *  The entity type to create a flag handler for. This may be FALSE if the

 *  entity type property could not be found in the flag configuration data.

 *

 * @return

 *  A flag handler object. This may be the special class flag_broken is there is

 *  a problem with the flag.

 */

function flag_create_handler($entity_type) {

  $definition = flag_fetch_definition($entity_type);

  if (isset($definition) && class_exists($definition['handler'])) {

    $handler = new $definition['handler'];

  }

  else {

    $handler = new flag_broken;

  }

  $handler->entity_type = $entity_type;

  $handler->construct();

  return $handler;

}

/**

 * Implements hook_permission().

 */

function flag_permission() {

  $permissions = array(

    'administer flags' => array(

      'title' => t('Administer flags'),

      'description' => t('Create and edit site-wide flags.'),

    ),

    'use flag import' => array(

      'title' => t('Use flag importer'),

      'description' => t('Access the flag import functionality.'),

      'restrict access' => TRUE,

    ),

  );

  $flags = flag_get_flags();

  // Provide flag and unflag permissions for each flag.

  foreach ($flags as $flag_name => $flag) {

    $permissions += $flag->get_permissions();

  }

  return $permissions;

}

/**

 * Implements hook_form_FORM_ID_alter(): user_admin_permissions.

 *

 * Disable permission on the permissions form that don't make sense for

 * anonymous users when Session API module is not enabled.

 */

function flag_form_user_admin_permissions_alter(&$form, &$form_state, $form_id) {

  if (!module_exists('session_api')) {

    $flags = flag_get_flags();

    // Disable flag and unflag permission checkboxes for anonymous users.

    foreach ($flags as $flag_name => $flag) {

      $form['checkboxes'][DRUPAL_ANONYMOUS_RID]["flag $flag_name"]['#disabled'] = TRUE;

      $form['checkboxes'][DRUPAL_ANONYMOUS_RID]["unflag $flag_name"]['#disabled'] = TRUE;

    }

  }

}

/**

 * Implements hook_flag_link().

 */

function flag_flag_link($flag, $action, $entity_id) {

  $token = flag_get_token($entity_id);

  return array(

    'href' => 'flag/' . ($flag->link_type == 'confirm' ? 'confirm/' : '') . "$action/$flag->name/$entity_id",

    'query' => drupal_get_destination() + ($flag->link_type == 'confirm' ? array() : array('token' => $token)),

  );

}

/**

 * Implements hook_field_extra_fields().

 */

function flag_field_extra_fields() {

  $extra = array();

  $flags = flag_get_flags();

  foreach ($flags as $name => $flag) {

    // Skip flags that aren't on entities.

    if (!($flag instanceof flag_entity)) {

      continue;

    }

    $applicable_bundles = $flag->types;

    // If the list of bundles is empty, it indicates all bundles apply.

    if (empty($applicable_bundles)) {

      $entity_info = entity_get_info($flag->entity_type);

      $applicable_bundles = array_keys($entity_info['bundles']);

    }

    foreach ($applicable_bundles as $bundle_name) {

      if ($flag->show_on_form) {

        $extra[$flag->entity_type][$bundle_name]['form']['flag'] = array(

          'label' => t('Flags'),

          'description' => t('Checkboxes for toggling flags'),

          'weight' => 10

        );

      }

      if ($flag->show_as_field) {

        $extra[$flag->entity_type][$bundle_name]['display']['flag_' . $name] = array(

          // It would be nicer to use % as the placeholder, but the label is

          // run through check_plain() by field_ui_display_overview_form()

          // (arguably incorrectly; see http://drupal.org/node/1991292).

          'label' => t('Flag: @title', array(

            '@title' => $flag->title,

          )),

          'description' => t('Individual flag link'),

          'weight' => 10,

        );

      }

    }

  }

  return $extra;

}

/**

 * Implements hook_form_FORM_ID_alter(): node_type_form.

 */

function flag_form_node_type_form_alter(&$form, &$form_state, $form_id) {

  global $user;

  $flags = flag_get_flags('node', $form['#node_type']->type, $user);

  foreach ($flags as $flag) {

    if ($flag->show_on_form) {

      // To be able to process node tokens in flag labels, we create a fake

      // node and store it in the flag's cache for replace_tokens() to find,

      // with a fake ID.

      $flag->remember_entity('fake', (object) array(

        'nid' => NULL,

        'type' => $form['#node_type']->type,

        'title' => '',

      ));

      $var = 'flag_' . $flag->name . '_default';

      $form['workflow']['flag'][$var] = array(

        '#type' => 'checkbox',

        '#title' => $flag->get_label('flag_short', 'fake'),

        '#default_value' => variable_get($var . '_' . $form['#node_type']->type, 0),

        '#return_value' => 1,

      );

    }

  }

  if (isset($form['workflow']['flag'])) {

    $form['workflow']['flag'] += array(

      '#type' => 'item',

      '#title' => t('Default flags'),

      '#description' => t('Above are the <a href="@flag-url">flags</a> you elected to show on the node editing form. You may specify their initial state here.', array('@flag-url' => url(FLAG_ADMIN_PATH))),

      // Make the spacing a bit more compact:

      '#prefix' => '<div class="form-checkboxes">',

      '#suffix' => '</div>',

    );

  }

}

/**

 * Implements hook_field_attach_form().

 *

 * Handles the 'show_on_form' flag option.

 *

 * Warning: will not work on entity types that are not fieldable, as this relies

 * on a field module hook.

 *

 * @see flag_field_attach_submit().

 */

function flag_field_attach_form($entity_type, $entity, &$form, &$form_state, $langcode) {

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

  // Some modules are being stupid here. Commerce!

  if (empty($id)) {

    $id = NULL;

  }

  // Keep track of whether the entity is new or not, as we're about to fiddle

  // with the entity id for the flag's entity cache.

  $is_existing_entity = !empty($id);

  // Get all possible flags for this entity type.

  $flags = flag_get_flags($entity_type);

  // Filter out flags which need to be included on the node form.

  $flags_in_form = 0;

  $flags_visible = 0;

  foreach ($flags as $flag) {

    if (!$flag->show_on_form) {

      continue;

    }

    // Get the flag status.

    if ($is_existing_entity) {

      $flag_status = $flag->is_flagged($id);

    }

    else {

      // We don't have per-bundle defaults on general entities yet: default

      // status is just unflagged.

      $flag_status = FALSE;

      // Apply the per-bundle defaults for nodes.

      if ($entity_type == 'node') {

        $node_type = $entity->type;

        $flag_status = variable_get('flag_' . $flag->name . '_default_' . $node_type, 0);

      }

      // For a new, unsaved entity, make a dummy entity ID so that the flag

      // handler can remember the entity. This allows access to the flag to be

      // correctly handled in node and comment preview.

      $id = 'new';

      $flag->remember_entity($id, $entity);

    }

    // If the flag is not global and the user doesn't have access, skip it.

    // Global flags have their value set even if the user doesn't have access

    // to it, similar to the way "published" and "promote" keep the default

    // values even if the user doesn't have "administer nodes" permission.

    // Furthermore, a global flag is set to its default value on new nodes

    // even if the user creating the node doesn't have access to the flag.

    global $user;

    $access = $flag->access($id, $flag_status ? 'unflag' : 'flag');

    if (!$access && !$flag->global) {

      continue;

    }

    $form['flag'][$flag->name] = array(

      '#type' => 'checkbox',

      '#title' => $flag->get_label('flag_short', $id),

      '#description' => $flag->get_label('flag_long', $id),

      '#default_value' => $flag_status,

      '#return_value' => 1,

      // Used by our drupalSetSummary() on vertical tabs.

      '#attributes' => array('title' => $flag->get_title()),

    );

    // If the user does not have access to the flag, set as a value.

    if (!$access) {

      $form['flag'][$flag->name]['#type'] = 'value';

      $form['flag'][$flag->name]['#value'] = $flag_status;

    }

    else {

      $flags_visible++;

    }

    $flags_in_form++;

  }

  if ($flags_in_form) {

    $form['flag'] += array(

      '#weight' => 1,

      '#tree' => TRUE,

    );

  }

  if ($flags_visible) {

    $form['flag'] += array(

      '#type' => 'fieldset',

      '#title' => t('Flags'),

      '#collapsible' => TRUE,

    );

    if ($entity_type == 'node') {

      // Turn the fieldset into a vertical tab.

      $form['flag'] += array(

        '#group' => 'additional_settings',

        '#attributes' => array('class' => array('flag-fieldset')),

        '#attached' => array(

          'js' => array(

            'vertical-tabs' => drupal_get_path('module', 'flag') . '/theme/flag-admin.js',

          ),

        ),

      );

    }

  }

}

/**

 * Implements hook_field_attach_submit().

 *

 * @see flag_field_attach_form().

 */

function flag_field_attach_submit($entity_type, $entity, $form, &$form_state) {

  // This is invoked for each flag_field_attach_form(), but possibly more than

  // once for a particular form in the case that a form is showing multiple

  // entities (field collection, inline entity form). Hence we can't simply

  // assume our submitted form values are in $form_state['values']['flag'].

  if (isset($form['flag'])) {

    $parents = $form['flag']['#parents'];

    $flag_values = drupal_array_get_nested_value($form_state['values'], $parents);

    // Put the form values in the entity so flag_field_attach_save() can find

    // them. We can't call flag() here as new entities have no id yet.

    $entity->flag = $flag_values;

  }

}

/**

 * Implements hook_field_attach_insert().

 */

function flag_field_attach_insert($entity_type, $entity) {

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

    flag_field_attach_save($entity_type, $entity);

  }

}

/**

 * Implements hook_field_attach_update().

 */

function flag_field_attach_update($entity_type, $entity) {

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

    flag_field_attach_save($entity_type, $entity);

  }

}

/**

 * Shared saving routine between flag_field_attach_insert/update().

 *

 * @see flag_field_attach_form().

 */

function flag_field_attach_save($entity_type, $entity) {

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

  // Get the flag values we stashed in the entity in flag_field_attach_submit().

  foreach ($entity->flag as $flag_name => $state) {

    flag($state ? 'flag' : 'unflag', $flag_name, $id);

  }

}

/*

 * Implements hook_contextual_links_view_alter().

 */

function flag_contextual_links_view_alter(&$element, $items) {

  if (isset($element['#element']['#entity_type'])) {

    $entity_type = $element['#element']['#entity_type'];

    // Get the entity out of the element. This requires a bit of legwork.

    if (isset($element['#element']['#entity'])) {

      // EntityAPI entities will all have the entity in the same place.

      $entity = $element['#element']['#entity'];

    }

    elseif (isset($element['#element']['#' . $entity_type])) {

      // Node module at least puts it here.

      $entity = $element['#element']['#' . $entity_type];

    }

    else {

      // Give up.

      return;

    }

    // Get all possible flags for this entity type.

    $flags = flag_get_flags($entity_type);

    foreach ($flags as $name => $flag) {

      if (!$flag->show_contextual_link) {

        continue;

      }

      list($entity_id) = entity_extract_ids($entity_type, $entity);

      if (!$flag->access($entity_id) && (!$flag->is_flagged($entity_id) || !$flag->access($entity_id, 'flag'))) {

        // User has no permission to use this flag or flag does not apply to this

        // object. The link is not skipped if the user has "flag" access but

        // not "unflag" access (this way the unflag denied message is shown).

        continue;

      }

      $element['#links']['flag-'. $name] = array(

        'title' => $flag->theme($flag->is_flagged($entity_id) ? 'unflag' : 'flag', $entity_id),

        'html' => TRUE,

      );

    }

  }

}

/**

 * Implements hook_entity_view().

 *

 * Handles the 'show_in_links' and 'show_as_field' flag options.

 *

 * Note this is broken for taxonomy terms for version of Drupal core < 7.17.

 */

function flag_entity_view($entity, $type, $view_mode, $langcode) {

  // Get all possible flags for this entity type.

  $flags = flag_get_flags($type);

  foreach ($flags as $flag) {

    // Check if the flag outputs on entity view.

    if (!($flag->show_as_field || $flag->shows_in_entity_links($view_mode))) {

      // Flag is not configured to output on entity view, so skip it to save on

      // calls to access checks.

      continue;

    }

    $entity_id = $flag->get_entity_id($entity);

    // For a new, unsaved entity, make a dummy entity ID so that the flag

    // handler can remember the entity. This allows access to the flag to be

    // correctly handled in node and comment preview.

    if (is_null($entity_id)) {

      $entity_id = 'new';

    }

    $flag->remember_entity($entity_id, $entity);

    if (!$flag->access($entity_id) && (!$flag->is_flagged($entity_id) || !$flag->access($entity_id, 'flag'))) {

      // User has no permission to use this flag or flag does not apply to this

      // entity. The link is not skipped if the user has "flag" access but

      // not "unflag" access (this way the unflag denied message is shown).

      continue;

    }

    // We're good to go. Output the flag in the appropriate manner(s).

    // The old-style entity links output.

    if ($flag->shows_in_entity_links($view_mode)) {

      // The flag links are actually fully rendered theme functions.

      // The HTML attribute is set to TRUE to allow whatever the themer desires.

      $links['flag-' . $flag->name] = array(

        'title' => $flag->theme($flag->is_flagged($entity_id) ? 'unflag' : 'flag', $entity_id),

        'html' => TRUE,

      );

    }

    // The pseudofield output.

    if ($flag->show_as_field) {

      $entity->content['flag_' . $flag->name] = array(

       '#markup' => $flag->theme($flag->is_flagged($entity_id) ? 'unflag' : 'flag', $entity_id, array('needs_wrapping_element' => TRUE)),

      );

    }

  }

  // If any links were made, add them to the entity's links array.

  if (isset($links)) {

    $entity->content['links']['flag'] = array(

      '#theme' => 'links',

      '#links' => $links,

      '#attributes' => array('class' => array('links', 'inline')),

    );

  }

}

/**

 * Implements hook_node_insert().

 */

function flag_node_insert($node) {

  flag_node_save($node);

}

/**

 * Implements hook_node_update().

 */

function flag_node_update($node) {

  flag_node_save($node);

}

/**

 * Shared saving routine between flag_node_insert() and flag_node_update().

 */

function flag_node_save($node) {

  // Response to the flag checkboxes added to the form in flag_form_alter().

  $remembered = FALSE;

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

    foreach ($node->flag as $name => $state) {

      $flag = flag_get_flag($name);

      // Flagging may trigger actions. We want actions to get the current

      // node, not a stale database-loaded one:

      if (!$remembered) {

        $flag->remember_entity($node->nid, $node);

        // Actions may modify a node, and we don't want to overwrite this

        // modification:

        $remembered = TRUE;

      }

      $action = $state ? 'flag' : 'unflag';

      // Pass TRUE for $skip_permission_check so that flags that have been

      // passed through as hidden form values are saved.

      $flag->flag($action, $node->nid, NULL, TRUE);

    }

  }

}

/**

 * Implements hook_entity_delete().

 */

function flag_entity_delete($entity, $type) {

  // Node and user flags handle things through the entity type delete hooks.

  // @todo: make this configurable in the flag type definition?

  if ($type == 'node' || $type == 'user') {

    return;

  }

  list($id) = entity_extract_ids($type, $entity);

  _flag_entity_delete($type, $id);

}

/**

 * Implements hook_node_delete().

 */

function flag_node_delete($node) {

  foreach (flag_get_flags('node') as $flag) {

    // If the flag is being tracked by translation set and the node is part

    // of a translation set, don't delete the flagging record.

    // Instead, data will be updated in hook_node_translation_change(), below.

    if (!$flag->i18n || empty($node->tnid)) {

      _flag_entity_delete('node', $node->nid, $flag->fid);

    }

  }

}

/**

 * Implements hook_node_translation_change().

 *

 * (Hook provided by translation_helpers module.)

 */

function flag_node_translation_change($node) {

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

    // If there is only one node remaining, track by nid rather than tnid.

    // Otherwise, use the new tnid.

    $entity_id = $node->translation_change['new_tnid'] == 0 ? $node->translation_change['remaining_nid'] : $node->translation_change['new_tnid'];

    foreach (flag_get_flags('node') as $flag) {

      if ($flag->i18n) {

        db_update('flagging')->fields(array('entity_id' => $entity_id))

          ->condition('fid', $flag->fid)

          ->condition('entity_id', $node->translation_change['old_tnid'])

          ->execute();

        db_update('flag_counts')->fields(array('entity_id' => $entity_id))

          ->condition('fid', $flag->fid)

          ->condition('entity_id', $node->translation_change['old_tnid'])

          ->execute();

      }

    }

  }

}

/**

 * Deletes flagging records for the entity.

 *

 * @param $entity_type

 *   The type of the entity being deleted; e.g. 'node' or 'comment'.

 * @param $entity_id

 *   The ID of the entity being deleted.

 * @param $fid

 *   The flag id

 */

function _flag_entity_delete($entity_type, $entity_id, $fid = NULL) {

  $query_content = db_delete('flagging')

    ->condition('entity_type', $entity_type)

    ->condition('entity_id', $entity_id);

  $query_counts = db_delete('flag_counts')

    ->condition('entity_type', $entity_type)

    ->condition('entity_id', $entity_id);

  if (isset($fid)) {

    $query_content->condition('fid', $fid);

    $query_counts->condition('fid', $fid);

  }

  $query_content->execute();

  $query_counts->execute();

}

/**

 * Implements hook_user_login().

 */

function flag_user_login(&$edit, &$account) {

  // Migrate anonymous flags to this user's account.

  if (module_exists('session_api') && ($sid = flag_get_sid(0))) {

    // Get a list of flagging IDs that will be moved over.

    $duplicate_flaggings = array();

    $flaggings = db_select('flagging', 'fc')

      ->fields('fc', array('flagging_id', 'fid', 'entity_id'))

      ->condition('uid', 0)

      ->condition('sid', $sid)

      ->execute()

      ->fetchAllAssoc('flagging_id', PDO::FETCH_ASSOC);

    // Convert anonymous flaggings to their authenticated account.

    foreach ($flaggings as $flagging_id => $flagging) {

      // Each update is wrapped in a try block to prevent unique key errors.

      // Any duplicate object that was flagged as anonoymous is deleted in the

      // subsequent db_delete() call.

      try {

        db_update('flagging')

          ->fields(array(

            'uid' => $account->uid,

            'sid' => 0,

          ))

          ->condition('flagging_id', $flagging_id)

          ->execute();

      }

      catch (Exception $e) {

        $duplicate_flaggings[$flagging_id] = $flagging;

      }

    }

    // Delete any remaining flags this user had as an anonymous user. We use the

    // proper unflag action here to make sure the count gets decremented again

    // and so that other modules can clean up their tables if needed.

    $anonymous_user = drupal_anonymous_user();

    foreach ($duplicate_flaggings as $flagging_id => $flagging) {

      $flag = flag_get_flag(NULL, $flagging['fid']);

      $flag->flag('unflag', $flagging['entity_id'], $anonymous_user, TRUE);

    }

    // Clean up anonymous cookies.

    FlagCookieStorage::drop();

  }

}

/**

 * Implements hook_user_cancel().

 */

function flag_user_cancel($edit, $account, $method) {

  flag_user_account_removal($account);

}

/**

 * Implements hook_user_delete().

 */

function flag_user_delete($account) {

  flag_user_account_removal($account);

}

/**

 * Shared helper for user account cancellation or deletion.

 */

function flag_user_account_removal($account) {

  // Remove flags by this user.

  $query = db_select('flagging', 'fc');

  $query->leftJoin('flag_counts', 'c', 'fc.entity_id = c.entity_id AND fc.entity_type = c.entity_type');

  $result = $query

    ->fields('fc', array('fid', 'entity_id'))

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

    ->condition('fc.uid', $account->uid)

    ->execute();

  foreach ($result as $flag_data) {

    // Only decrement the flag count table if it's greater than 1.

    if ($flag_data->count > 0) {

      $flag_data->count--;

      db_update('flag_counts')

        ->fields(array(

          'count' => $flag_data->count,

        ))

        ->condition('fid', $flag_data->fid)

        ->condition('entity_id', $flag_data->entity_id)

        ->execute();

    }

    elseif ($flag_data->count == 0) {

      db_delete('flag_counts')

        ->condition('fid', $flag_data->fid)

        ->condition('entity_id', $flag_data->entity_id)

        ->execute();

    }

  }

  db_delete('flagging')

    ->condition('uid', $account->uid)

    ->execute();

  // Remove flags that have been done to this user.

  _flag_entity_delete('user', $account->uid);

}

/**

 * Implements hook_user_view().

 */

function flag_user_view($account, $view_mode) {

  $flags = flag_get_flags('user');

  $flag_items = array();

  foreach ($flags as $flag) {

    if (!$flag->access($account->uid)) {

      // User has no permission to use this flag.

      continue;

    }

    if (!$flag->show_on_profile) {

      // Flag not set to appear on profile.

      continue;

    }

    $flag_items[$flag->name] = array(

      '#type' => 'user_profile_item',

      '#title' => $flag->get_title($account->uid),

      '#markup' => $flag->theme($flag->is_flagged($account->uid) ? 'unflag' : 'flag', $account->uid),

      '#attributes' => array('class' => array('flag-profile-' . $flag->name)),

    );

  }

  if (!empty($flag_items)) {

    $account->content['flags'] = $flag_items;

    $account->content['flags'] += array(

      '#type' => 'user_profile_category',

      '#title' => t('Actions'),

      '#attributes' => array('class' => array('flag-profile')),

    );

  }

}

/**

 * Implements hook_session_api_cleanup().

 *

 * Clear out anonymous user flaggings during Session API cleanup.

 */

function flag_session_api_cleanup($arg = 'run') {

  // Session API 1.1 version:

  if ($arg == 'run') {

    $query = db_select('flagging', 'fc');

    $query->leftJoin('session_api', 's', 'fc.sid = s.sid');

    $result = $query

      ->fields('fc', array('sid'))

      ->condition('fc.sid', 0, '<>')

      ->isNull('s.sid')

      ->execute();

    foreach ($result as $row) {

      db_delete('flagging')

        ->condition('sid', $row->sid)

        ->execute();

    }

  }

  // Session API 1.2+ version.

  elseif (is_array($arg)) {

    $outdated_sids = $arg;

    db_delete('flagging')->condition('sid', $outdated_sids, 'IN')->execute();

  }

}

/**

 * Implements hook_field_attach_delete_bundle().

 *

 * Delete any flags' applicability to the deleted bundle.

 */

function flag_field_attach_delete_bundle($entity_type, $bundle, $instances) {

  // This query can't use db_delete() because that doesn't support a

  // subquery: see http://drupal.org/node/1267508.

  db_query("DELETE FROM {flag_types} WHERE type = :bundle AND fid IN (SELECT fid FROM {flag} WHERE entity_type = :entity_type)", array(

    ':bundle' => $bundle,

    ':entity_type' => $entity_type,

  ));

}

/**

 * Flags or unflags an item.

 *

 * @param $action

 *   Either 'flag' or 'unflag'.

 * @param $flag_name

 *   The name of the flag to use.

 * @param $entity_id

 *   The ID of the item to flag or unflag.

 * @param $account

 *   (optional) The user on whose behalf to flag. Omit for the current user.

 * @param permissions_check

 *   (optional) A boolean indicating whether to skip permissions.

 *

 * @return

 *   FALSE if some error occured (e.g., user has no permission, flag isn't

 *   applicable to the item, etc.), TRUE otherwise.

 */

function flag($action, $flag_name, $entity_id, $account = NULL, $permissions_check = FALSE) {

  if (!($flag = flag_get_flag($flag_name))) {

    // Flag does not exist.

    return FALSE;

  }

  return $flag->flag($action, $entity_id, $account, $permissions_check);

}

/**

 * Implements hook_flag_flag().

 */

function flag_flag_flag($flag, $entity_id, $account, $flagging) {

  if (module_exists('trigger')) {

    flag_flag_trigger('flag', $flag, $entity_id, $account, $flagging);

  }

}

/**

 * Implements hook_flag_unflag().

 */

function flag_flag_unflag($flag, $entity_id, $account, $flagging) {

  if (module_exists('trigger')) {

    flag_flag_trigger('unflag', $flag, $entity_id, $account, $flagging);

  }

}

/**

 * Trigger actions if any are available. Helper for hook_flag_(un)flag().

 *

 * @param $op

 *  The operation being performed: one of 'flag' or 'unflag'.

 * @param $flag

 *  The flag object.

 * @param $entity_id

 *  The id of the entity the flag is on.

 * @param $account

 *  The user account performing the action.

 * @param $flagging_id

 *  The flagging entity.

 */

function flag_flag_trigger($action, $flag, $entity_id, $account, $flagging) {

  $context['hook'] = 'flag';

  $context['account'] = $account;

  $context['flag'] = $flag;

  $context['op'] = $action;

  // We add to the $context all the objects we know about:

  $context = array_merge($flag->get_relevant_action_objects($entity_id), $context);

  // The primary object the actions work on.

  $object = $flag->fetch_entity($entity_id);

  // Generic "all flags" actions.

  foreach (trigger_get_assigned_actions('flag_' . $action)  as $aid => $action_info) {

    // The 'if ($aid)' is a safeguard against http://drupal.org/node/271460#comment-886564

    if ($aid) {

      actions_do($aid, $object, $context);

    }

  }

  // Actions specifically for this flag.

  foreach (trigger_get_assigned_actions('flag_' . $action . '_' . $flag->name) as $aid => $action_info) {

    if ($aid) {

      actions_do($aid, $object, $context);

    }

  }

}

/**

 * Implements hook_flag_access().

 */

function flag_flag_access($flag, $entity_id, $action, $account) {

  // Do nothing if there is no restriction by authorship.

  if (empty($flag->access_author)) {

    return;

  }

  // Restrict access by authorship. It's important that TRUE is never returned

  // here, otherwise we'd grant permission even if other modules denied access.

  if ($flag->entity_type == 'node') {

    // For non-existent nodes (such as on the node add form), assume that the

    // current user is creating the content.

    if (empty($entity_id) || !($node = $flag->fetch_entity($entity_id))) {

      return $flag->access_author == 'others' ? FALSE : NULL;

    }

    if ($flag->access_author == 'own' && $node->uid != $account->uid) {

      return FALSE;

    }

    elseif ($flag->access_author == 'others' && $node->uid == $account->uid) {

      return FALSE;

    }

  }

  // Restrict access by comment authorship.

  if ($flag->entity_type == 'comment') {

    // For non-existent comments (such as on the comment add form), assume that

    // the current user is creating the content.

    if (empty($entity_id) || !($comment = $flag->fetch_entity($entity_id))) {

      return $flag->access_author == 'comment_others' ? FALSE : NULL;

    }

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

    if ($flag->access_author == 'node_own' && $node->uid != $account->uid) {

      return FALSE;

    }

    elseif ($flag->access_author == 'node_others' && $node->uid == $account->uid) {

      return FALSE;

    }

    elseif ($flag->access_author == 'comment_own' && $comment->uid != $account->uid) {

      return FALSE;

    }

    elseif ($flag->access_author == 'comment_others' && $comment->uid == $account->uid) {

      return FALSE;

    }

  }

}

/**

 * Implements hook_flag_access_multiple().

 */

function flag_flag_access_multiple($flag, $entity_ids, $account) {

  $access = array();

  // Do nothing if there is no restriction by authorship.

  if (empty($flag->access_author)) {

    return $access;

  }

  if ($flag->entity_type == 'node') {

    // Restrict access by authorship. This is similar to flag_flag_access()

    // above, but returns an array of 'nid' => $access values. Similarly, we

    // should never return TRUE in any of these access values, only FALSE if we

    // want to deny access, or use the current access value provided by Flag.

    $result = db_select('node', 'n')

      ->fields('n', array('nid', 'uid'))

      ->condition('nid', array_keys($entity_ids), 'IN')

      ->condition('type', $flag->types, 'IN')

      ->execute();

    foreach ($result as $row) {

      if ($flag->access_author == 'own') {

        $access[$row->nid] = $row->uid != $account->uid ? FALSE : NULL;

      }

      elseif ($flag->access_author == 'others') {

        $access[$row->nid] = $row->uid == $account->uid ? FALSE : NULL;

      }

    }

  }

  if ($flag->entity_type == 'comment') {

    // Restrict access by comment ownership.

    $query = db_select('comment', 'c');

    $query->leftJoin('node', 'n', 'c.nid = n.nid');

    $query

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

      ->condition('c.cid', $entity_ids, 'IN');

    $query->addField('c', 'uid', 'comment_uid');

    $result = $query->execute();

    foreach ($result as $row) {

      if ($flag->access_author == 'node_own') {

        $access[$row->cid] = $row->node_uid != $account->uid ? FALSE : NULL;

      }

      elseif ($flag->access_author == 'node_others') {

        $access[$row->cid] = $row->node_uid == $account->uid ? FALSE : NULL;

      }

      elseif ($flag->access_author == 'comment_own') {

        $access[$row->cid] = $row->comment_uid != $account->uid ? FALSE : NULL;

      }

      elseif ($flag->access_author == 'comment_others') {

        $access[$row->cid] = $row->comment_uid == $account->uid ? FALSE : NULL;

      }

    }

  }

  // Always return an array (even if empty) of accesses.

  return $access;

}

/**

 * Implements hook_theme().

 */

function flag_theme() {

  $path = drupal_get_path('module', 'flag') . '/theme';

  return array(

    'flag' => array(

      'variables' => array(

        'flag' => NULL,

        'action' => NULL,

        'entity_id' => NULL,

        'after_flagging' => FALSE,

        'needs_wrapping_element' => FALSE,

        'errors' => array(),

      ),

      'template' => 'flag',

      'pattern' => 'flag__',

      'path' => $path,

    ),

    'flag_tokens_browser' => array(

      'variables' => array(

        'types' => array('all'),

        'global_types' => TRUE,

      ),

      'file' => 'flag.tokens.inc',

    ),

    'flag_admin_listing' => array(

      'render element' => 'form',

      'file' => 'includes/flag.admin.inc',

    ),

    'flag_admin_listing_disabled' => array(

      'variables' => array(

        'flags' => NULL,

        'default_flags' => NULL,

      ),

      'file' => 'includes/flag.admin.inc',

    ),

    'flag_admin_page' => array(

      'variables' => array(

        'flags' => NULL,

        'default_flags' => NULL,

        'flag_admin_listing' => NULL,

      ),

      'file' => 'includes/flag.admin.inc',

    ),

    'flag_form_roles' => array(

      'render element' => 'element',

      'file' => 'includes/flag.admin.inc',

    ),

  );

}

/**

 * A preprocess function for our theme('flag'). It generates the

 * variables needed there.

 *

 * The $variables array initially contains the following arguments:

 * - $flag

 * - $action

 * - $entity_id

 * - $after_flagging

 * - $errors

 * - $needs_wrapping_element

 *

 * See 'flag.tpl.php' for their documentation.

 */

function template_preprocess_flag(&$variables) {

  global $user;

  $initialized = &drupal_static(__FUNCTION__, array());

  // Some typing shotcuts:

  $flag =& $variables['flag'];

  $action = $variables['action'];

  $entity_id = $variables['entity_id'];

  $errors = join('<br />', $variables['errors']);

  $flag_css_name = str_replace('_', '-', $flag->name);

  // Generate the link URL.

  $link_type = $flag->get_link_type();

  $link = module_invoke($link_type['module'], 'flag_link', $flag, $action, $entity_id);

  if (isset($link['title']) && empty($link['html'])) {

    $link['title'] = check_plain($link['title']);

  }

  // Replace the link with the access denied text if unable to flag.

  if ($action == 'unflag' && !$flag->access($entity_id, 'unflag')) {

    $link['title'] = $flag->get_label('unflag_denied_text', $entity_id);

    unset($link['href']);

  }