array(), 'indexes' => array(), 'foreign keys' => array()); // Give other modules a chance to alter this definition. // @see hook_field_schema_alter() drupal_alter('field_schema', $schema, $field); return $schema; } /** * Creates a field. * * This function does not bind the field to any bundle; use * field_create_instance() for that. * * @param $field * A field definition array. The field_name and type properties are required. * Other properties, if omitted, will be given the following default values: * - cardinality: 1 * - locked: FALSE * - indexes: the field-type indexes, specified by the field type's * hook_field_schema(). The indexes specified in $field are added * to those default indexes. It is possible to override the * definition of a field-type index by providing an index with the * same name, or to remove it by redefining it as an empty array * of columns. Overriding field-type indexes should be done * carefully, for it might seriously affect the site's performance. * - settings: each omitted setting is given the default value defined in * hook_field_info(). * - storage: * - type: the storage backend specified in the 'field_storage_default' * system variable. * - settings: each omitted setting is given the default value specified in * hook_field_storage_info(). * * @return * The $field array with the id property filled in. * * @throws FieldException * * See: @link field Field API data structures @endlink. */ function field_create_field($field) { // Field name is required. if (empty($field['field_name'])) { throw new FieldException('Attempt to create an unnamed field.'); } // Field type is required. if (empty($field['type'])) { throw new FieldException(format_string('Attempt to create field @field_name with no type.', array('@field_name' => $field['field_name']))); } // Field name cannot contain invalid characters. if (!preg_match('/^[_a-z]+[_a-z0-9]*$/', $field['field_name'])) { throw new FieldException(format_string('Attempt to create a field @field_name with invalid characters. Only lowercase alphanumeric characters and underscores are allowed, and only lowercase letters and underscore are allowed as the first character', array('@field_name' => $field['field_name']))); } // Field name cannot be longer than 32 characters. We use drupal_strlen() // because the DB layer assumes that column widths are given in characters, // not bytes. if (drupal_strlen($field['field_name']) > 32) { throw new FieldException(t('Attempt to create a field with a name longer than 32 characters: %name', array('%name' => $field['field_name']))); } // Ensure the field name is unique over active and disabled fields. // We do not care about deleted fields. $prior_field = field_read_field($field['field_name'], array('include_inactive' => TRUE)); if (!empty($prior_field)) { $message = $prior_field['active']? t('Attempt to create field name %name which already exists and is active.', array('%name' => $field['field_name'])): t('Attempt to create field name %name which already exists, although it is inactive.', array('%name' => $field['field_name'])); throw new FieldException($message); } // Disallow reserved field names. This can't prevent all field name // collisions with existing entity properties, but some is better // than none. foreach (entity_get_info() as $type => $info) { if (in_array($field['field_name'], $info['entity keys'])) { throw new FieldException(t('Attempt to create field name %name which is reserved by entity type %type.', array('%name' => $field['field_name'], '%type' => $type))); } } $field += array( 'entity_types' => array(), 'cardinality' => 1, 'translatable' => FALSE, 'locked' => FALSE, 'settings' => array(), 'storage' => array(), 'deleted' => 0, ); // Check that the field type is known. $field_type = field_info_field_types($field['type']); if (!$field_type) { throw new FieldException(t('Attempt to create a field of unknown type %type.', array('%type' => $field['type']))); } // Create all per-field-type properties (needed here as long as we have // settings that impact column definitions). $field['settings'] += field_info_field_settings($field['type']); $field['module'] = $field_type['module']; $field['active'] = 1; // Provide default storage. $field['storage'] += array( 'type' => variable_get('field_storage_default', 'field_sql_storage'), 'settings' => array(), ); // Check that the storage type is known. $storage_type = field_info_storage_types($field['storage']['type']); if (!$storage_type) { throw new FieldException(t('Attempt to create a field with unknown storage type %type.', array('%type' => $field['storage']['type']))); } // Provide default storage settings. $field['storage']['settings'] += field_info_storage_settings($field['storage']['type']); $field['storage']['module'] = $storage_type['module']; $field['storage']['active'] = 1; // Collect storage information. $schema = field_retrieve_schema($field); // 'columns' are hardcoded in the field type. $field['columns'] = $schema['columns']; // 'foreign keys' are hardcoded in the field type. $field['foreign keys'] = $schema['foreign keys']; // 'indexes' can be both hardcoded in the field type, and specified in the // incoming $field definition. $field += array( 'indexes' => array(), ); $field['indexes'] += $schema['indexes']; // The serialized 'data' column contains everything from $field that does not // have its own column and is not automatically populated when the field is // read. $data = $field; unset($data['columns'], $data['field_name'], $data['type'], $data['active'], $data['module'], $data['storage_type'], $data['storage_active'], $data['storage_module'], $data['locked'], $data['cardinality'], $data['deleted']); // Additionally, do not save the 'bundles' property populated by // field_info_field(). unset($data['bundles']); $record = array( 'field_name' => $field['field_name'], 'type' => $field['type'], 'module' => $field['module'], 'active' => $field['active'], 'storage_type' => $field['storage']['type'], 'storage_module' => $field['storage']['module'], 'storage_active' => $field['storage']['active'], 'locked' => $field['locked'], 'data' => $data, 'cardinality' => $field['cardinality'], 'translatable' => $field['translatable'], 'deleted' => $field['deleted'], ); // Store the field and get the id back. drupal_write_record('field_config', $record); $field['id'] = $record['id']; // Invoke hook_field_storage_create_field after the field is // complete (e.g. it has its id). try { // Invoke hook_field_storage_create_field after // drupal_write_record() sets the field id. module_invoke($storage_type['module'], 'field_storage_create_field', $field); } catch (Exception $e) { // If storage creation failed, remove the field_config record before // rethrowing the exception. db_delete('field_config') ->condition('id', $field['id']) ->execute(); throw $e; } // Clear caches field_cache_clear(); // Invoke external hooks after the cache is cleared for API consistency. module_invoke_all('field_create_field', $field); return $field; } /** * Updates a field. * * Any module may forbid any update for any reason. For example, the * field's storage module might forbid an update if it would change * the storage schema while data for the field exists. A field type * module might forbid an update if it would change existing data's * semantics, or if there are external dependencies on field settings * that cannot be updated. * * @param $field * A field structure. $field['field_name'] must provided; it * identifies the field that will be updated to match this * structure. Any other properties of the field that are not * specified in $field will be left unchanged, so it is not * necessary to pass in a fully populated $field structure. * @return * Throws a FieldException if the update cannot be performed. * @see field_create_field() */ function field_update_field($field) { // Check that the specified field exists. $prior_field = field_read_field($field['field_name']); if (empty($prior_field)) { throw new FieldException('Attempt to update a non-existent field.'); } // Use the prior field values for anything not specifically set by the new // field to be sure that all values are set. $field += $prior_field; $field['settings'] += $prior_field['settings']; // Some updates are always disallowed. if ($field['type'] != $prior_field['type']) { throw new FieldException("Cannot change an existing field's type."); } if ($field['entity_types'] != $prior_field['entity_types']) { throw new FieldException("Cannot change an existing field's entity_types property."); } if ($field['storage']['type'] != $prior_field['storage']['type']) { throw new FieldException("Cannot change an existing field's storage type."); } // Collect the new storage information, since what is in // $prior_field may no longer be right. $schema = field_retrieve_schema($field); // 'columns' are hardcoded in the field type. $field['columns'] = $schema['columns']; // 'foreign keys' are hardcoded in the field type. $field['foreign keys'] = $schema['foreign keys']; // 'indexes' can be both hardcoded in the field type, and specified in the // incoming $field definition. $field += array( 'indexes' => array(), ); $field['indexes'] += $schema['indexes']; $has_data = field_has_data($field); // See if any module forbids the update by throwing an exception. foreach (module_implements('field_update_forbid') as $module) { $function = $module . '_field_update_forbid'; $function($field, $prior_field, $has_data); } // Tell the storage engine to update the field. Do this before // saving the new definition since it still might fail. $storage_type = field_info_storage_types($field['storage']['type']); module_invoke($storage_type['module'], 'field_storage_update_field', $field, $prior_field, $has_data); // Save the new field definition. @todo: refactor with // field_create_field. // The serialized 'data' column contains everything from $field that does not // have its own column and is not automatically populated when the field is // read. $data = $field; unset($data['columns'], $data['field_name'], $data['type'], $data['locked'], $data['module'], $data['cardinality'], $data['active'], $data['deleted']); // Additionally, do not save the 'bundles' property populated by // field_info_field(). unset($data['bundles']); $field['data'] = $data; // Store the field and create the id. $primary_key = array('id'); drupal_write_record('field_config', $field, $primary_key); // Clear caches field_cache_clear(); // Invoke external hooks after the cache is cleared for API consistency. module_invoke_all('field_update_field', $field, $prior_field, $has_data); } /** * Reads a single field record directly from the database. * * Generally, you should use the field_info_field() instead. * * This function will not return deleted fields. Use * field_read_fields() instead for this purpose. * * @param $field_name * The field name to read. * @param array $include_additional * The default behavior of this function is to not return a field that * is inactive. Setting * $include_additional['include_inactive'] to TRUE will override this * behavior. * @return * A field definition array, or FALSE. */ function field_read_field($field_name, $include_additional = array()) { $fields = field_read_fields(array('field_name' => $field_name), $include_additional); return $fields ? current($fields) : FALSE; } /** * Reads in fields that match an array of conditions. * * @param array $params * An array of conditions to match against. Keys are columns from the * 'field_config' table, values are conditions to match. Additionally, * conditions on the 'entity_type' and 'bundle' columns from the * 'field_config_instance' table are supported (select fields having an * instance on a given bundle). * @param array $include_additional * The default behavior of this function is to not return fields that * are inactive or have been deleted. Setting * $include_additional['include_inactive'] or * $include_additional['include_deleted'] to TRUE will override this * behavior. * @return * An array of fields matching $params. If * $include_additional['include_deleted'] is TRUE, the array is keyed * by field id, otherwise it is keyed by field name. */ function field_read_fields($params = array(), $include_additional = array()) { $query = db_select('field_config', 'fc', array('fetch' => PDO::FETCH_ASSOC)); $query->fields('fc'); // Turn the conditions into a query. foreach ($params as $key => $value) { // Allow filtering on the 'entity_type' and 'bundle' columns of the // field_config_instance table. if ($key == 'entity_type' || $key == 'bundle') { if (empty($fci_join)) { $fci_join = $query->join('field_config_instance', 'fci', 'fc.id = fci.field_id'); } $key = 'fci.' . $key; } else { $key = 'fc.' . $key; } $query->condition($key, $value); } if (!isset($include_additional['include_inactive']) || !$include_additional['include_inactive']) { $query ->condition('fc.active', 1) ->condition('fc.storage_active', 1); } $include_deleted = (isset($include_additional['include_deleted']) && $include_additional['include_deleted']); if (!$include_deleted) { $query->condition('fc.deleted', 0); } $fields = array(); $results = $query->execute(); foreach ($results as $record) { $field = unserialize($record['data']); $field['id'] = $record['id']; $field['field_name'] = $record['field_name']; $field['type'] = $record['type']; $field['module'] = $record['module']; $field['active'] = $record['active']; $field['storage']['type'] = $record['storage_type']; $field['storage']['module'] = $record['storage_module']; $field['storage']['active'] = $record['storage_active']; $field['locked'] = $record['locked']; $field['cardinality'] = $record['cardinality']; $field['translatable'] = $record['translatable']; $field['deleted'] = $record['deleted']; module_invoke_all('field_read_field', $field); // Populate storage information. $schema = field_retrieve_schema($field); $field['columns'] = $schema['columns']; $field_name = $field['field_name']; if ($include_deleted) { $field_name = $field['id']; } $fields[$field_name] = $field; } return $fields; } /** * Marks a field and its instances and data for deletion. * * @param $field_name * The field name to delete. */ function field_delete_field($field_name) { // Delete all non-deleted instances. $field = field_info_field($field_name); if (isset($field['bundles'])) { foreach ($field['bundles'] as $entity_type => $bundles) { foreach ($bundles as $bundle) { $instance = field_info_instance($entity_type, $field_name, $bundle); field_delete_instance($instance, FALSE); } } } // Mark field data for deletion. module_invoke($field['storage']['module'], 'field_storage_delete_field', $field); // Mark the field for deletion. db_update('field_config') ->fields(array('deleted' => 1)) ->condition('field_name', $field_name) ->execute(); // Clear the cache. field_cache_clear(); module_invoke_all('field_delete_field', $field); } /** * Creates an instance of a field, binding it to a bundle. * * @param $instance * A field instance definition array. The field_name, entity_type and * bundle properties are required. Other properties, if omitted, * will be given the following default values: * - label: the field name * - description: empty string * - required: FALSE * - default_value_function: empty string * - settings: each omitted setting is given the default value specified in * hook_field_info(). * - widget: * - type: the default widget specified in hook_field_info(). * - settings: each omitted setting is given the default value specified in * hook_field_widget_info(). * - display: * Settings for the 'default' view mode will be added if not present, and * each view mode in the definition will be completed with the following * default values: * - label: 'above' * - type: the default formatter specified in hook_field_info(). * - settings: each omitted setting is given the default value specified in * hook_field_formatter_info(). * View modes not present in the definition are left empty, and the field * will not be displayed in this mode. * * @return * The $instance array with the id property filled in. * * @throws FieldException * * See: @link field Field API data structures @endlink. * @see hook_field_schema_alter() */ function field_create_instance($instance) { $field = field_read_field($instance['field_name']); if (empty($field)) { throw new FieldException(t("Attempt to create an instance of a field @field_name that doesn't exist or is currently inactive.", array('@field_name' => $instance['field_name']))); } // Check that the required properties exists. if (empty($instance['entity_type'])) { throw new FieldException(t('Attempt to create an instance of field @field_name without an entity type.', array('@field_name' => $instance['field_name']))); } if (empty($instance['bundle'])) { throw new FieldException(t('Attempt to create an instance of field @field_name without a bundle.', array('@field_name' => $instance['field_name']))); } // Check that the field can be attached to this entity type. if (!empty($field['entity_types']) && !in_array($instance['entity_type'], $field['entity_types'])) { throw new FieldException(t('Attempt to create an instance of field @field_name on forbidden entity type @entity_type.', array('@field_name' => $instance['field_name'], '@entity_type' => $instance['entity_type']))); } // Set the field id. $instance['field_id'] = $field['id']; // Note that we do *not* prevent creating a field on non-existing bundles, // because that would break the 'Body as field' upgrade for contrib // node types. // TODO: Check that the widget type is known and can handle the field type ? // TODO: Check that the formatters are known and can handle the field type ? // TODO: Check that the display view modes are known for the entity type ? // Those checks should probably happen in _field_write_instance() ? // Problem : this would mean that a UI module cannot update an instance with a disabled formatter. // Ensure the field instance is unique within the bundle. // We only check for instances of active fields, since adding an instance of // a disabled field is not supported. $prior_instance = field_read_instance($instance['entity_type'], $instance['field_name'], $instance['bundle']); if (!empty($prior_instance)) { $message = t('Attempt to create an instance of field @field_name on bundle @bundle that already has an instance of that field.', array('@field_name' => $instance['field_name'], '@bundle' => $instance['bundle'])); throw new FieldException($message); } _field_write_instance($instance); // Clear caches field_cache_clear(); // Invoke external hooks after the cache is cleared for API consistency. module_invoke_all('field_create_instance', $instance); return $instance; } /** * Updates an instance of a field. * * @param $instance * An associative array representing an instance structure. The following * required array elements specify which field instance is being updated: * - entity_type: The type of the entity the field is attached to. * - bundle: The bundle this field belongs to. * - field_name: The name of an existing field. * The other array elements represent properties of the instance, and all * properties must be specified or their default values will be used (except * internal-use properties, which are assigned automatically). To avoid * losing the previously stored properties of the instance when making a * change, first load the instance with field_info_instance(), then override * the values you want to override, and finally save using this function. * Example: * @code * // Fetch an instance info array. * $instance_info = field_info_instance($entity_type, $field_name, $bundle_name); * // Change a single property in the instance definition. * $instance_info['required'] = TRUE; * // Write the changed definition back. * field_update_instance($instance_info); * @endcode * * @throws FieldException * * @see field_info_instance() * @see field_create_instance() */ function field_update_instance($instance) { // Check that the specified field exists. $field = field_read_field($instance['field_name']); if (empty($field)) { throw new FieldException(t('Attempt to update an instance of a nonexistent field @field.', array('@field' => $instance['field_name']))); } // Check that the field instance exists (even if it is inactive, since we // want to be able to replace inactive widgets with new ones). $prior_instance = field_read_instance($instance['entity_type'], $instance['field_name'], $instance['bundle'], array('include_inactive' => TRUE)); if (empty($prior_instance)) { throw new FieldException(t("Attempt to update an instance of field @field on bundle @bundle that doesn't exist.", array('@field' => $instance['field_name'], '@bundle' => $instance['bundle']))); } $instance['id'] = $prior_instance['id']; $instance['field_id'] = $prior_instance['field_id']; _field_write_instance($instance, TRUE); // Clear caches. field_cache_clear(); module_invoke_all('field_update_instance', $instance, $prior_instance); } /** * Stores an instance record in the field configuration database. * * @param $instance * An instance structure. * @param $update * Whether this is a new or existing instance. */ function _field_write_instance($instance, $update = FALSE) { $field = field_read_field($instance['field_name']); $field_type = field_info_field_types($field['type']); // Set defaults. $instance += array( 'settings' => array(), 'display' => array(), 'widget' => array(), 'required' => FALSE, 'label' => $instance['field_name'], 'description' => '', 'deleted' => 0, ); // Set default instance settings. $instance['settings'] += field_info_instance_settings($field['type']); // Set default widget and settings. $instance['widget'] += array( // TODO: what if no 'default_widget' specified ? 'type' => $field_type['default_widget'], 'settings' => array(), ); // If no weight specified, make sure the field sinks at the bottom. if (!isset($instance['widget']['weight'])) { $max_weight = field_info_max_weight($instance['entity_type'], $instance['bundle'], 'form'); $instance['widget']['weight'] = isset($max_weight) ? $max_weight + 1 : 0; } // Check widget module. $widget_type = field_info_widget_types($instance['widget']['type']); $instance['widget']['module'] = $widget_type['module']; $instance['widget']['settings'] += field_info_widget_settings($instance['widget']['type']); // Make sure there are at least display settings for the 'default' view mode, // and fill in defaults for each view mode specified in the definition. $instance['display'] += array( 'default' => array(), ); foreach ($instance['display'] as $view_mode => $display) { $display += array( 'label' => 'above', 'type' => isset($field_type['default_formatter']) ? $field_type['default_formatter'] : 'hidden', 'settings' => array(), ); if ($display['type'] != 'hidden') { $formatter_type = field_info_formatter_types($display['type']); $display['module'] = $formatter_type['module']; $display['settings'] += field_info_formatter_settings($display['type']); } // If no weight specified, make sure the field sinks at the bottom. if (!isset($display['weight'])) { $max_weight = field_info_max_weight($instance['entity_type'], $instance['bundle'], $view_mode); $display['weight'] = isset($max_weight) ? $max_weight + 1 : 0; } $instance['display'][$view_mode] = $display; } // The serialized 'data' column contains everything from $instance that does // not have its own column and is not automatically populated when the // instance is read. $data = $instance; unset($data['id'], $data['field_id'], $data['field_name'], $data['entity_type'], $data['bundle'], $data['deleted']); $record = array( 'field_id' => $instance['field_id'], 'field_name' => $instance['field_name'], 'entity_type' => $instance['entity_type'], 'bundle' => $instance['bundle'], 'data' => $data, 'deleted' => $instance['deleted'], ); // We need to tell drupal_update_record() the primary keys to trigger an // update. if ($update) { $record['id'] = $instance['id']; $primary_key = array('id'); } else { $primary_key = array(); } drupal_write_record('field_config_instance', $record, $primary_key); } /** * Reads a single instance record from the database. * * Generally, you should use field_info_instance() instead, as it * provides caching and allows other modules the opportunity to * append additional formatters, widgets, and other information. * * @param $entity_type * The type of entity to which the field is bound. * @param $field_name * The field name to read. * @param $bundle * The bundle to which the field is bound. * @param array $include_additional * The default behavior of this function is to not return an instance that * has been deleted, or whose field is inactive. Setting * $include_additional['include_inactive'] or * $include_additional['include_deleted'] to TRUE will override this * behavior. * @return * An instance structure, or FALSE. */ function field_read_instance($entity_type, $field_name, $bundle, $include_additional = array()) { $instances = field_read_instances(array('entity_type' => $entity_type, 'field_name' => $field_name, 'bundle' => $bundle), $include_additional); return $instances ? current($instances) : FALSE; } /** * Reads in field instances that match an array of conditions. * * @param $param * An array of properties to use in selecting a field * instance. Valid keys include any column of the * field_config_instance table. If NULL, all instances will be returned. * @param $include_additional * The default behavior of this function is to not return field * instances that have been marked deleted, or whose field is inactive. * Setting $include_additional['include_inactive'] or * $include_additional['include_deleted'] to TRUE will override this * behavior. * @return * An array of instances matching the arguments. */ function field_read_instances($params = array(), $include_additional = array()) { $include_inactive = isset($include_additional['include_inactive']) && $include_additional['include_inactive']; $include_deleted = isset($include_additional['include_deleted']) && $include_additional['include_deleted']; $query = db_select('field_config_instance', 'fci', array('fetch' => PDO::FETCH_ASSOC)); $query->join('field_config', 'fc', 'fc.id = fci.field_id'); $query->fields('fci'); // Turn the conditions into a query. foreach ($params as $key => $value) { $query->condition('fci.' . $key, $value); } if (!$include_inactive) { $query ->condition('fc.active', 1) ->condition('fc.storage_active', 1); } if (!$include_deleted) { $query->condition('fc.deleted', 0); $query->condition('fci.deleted', 0); } $instances = array(); $query->orderBy('fci.id'); $results = $query->execute(); foreach ($results as $record) { // Filter out instances on unknown entity types (for instance because the // module exposing them was disabled). $entity_info = entity_get_info($record['entity_type']); if ($include_inactive || $entity_info) { $instance = unserialize($record['data']); $instance['id'] = $record['id']; $instance['field_id'] = $record['field_id']; $instance['field_name'] = $record['field_name']; $instance['entity_type'] = $record['entity_type']; $instance['bundle'] = $record['bundle']; $instance['deleted'] = $record['deleted']; module_invoke_all('field_read_instance', $instance); $instances[] = $instance; } } return $instances; } /** * Marks a field instance and its data for deletion. * * @param $instance * An instance structure. * @param $field_cleanup * If TRUE, the field will be deleted as well if its last instance is being * deleted. If FALSE, it is the caller's responsibility to handle the case of * fields left without instances. Defaults to TRUE. */ function field_delete_instance($instance, $field_cleanup = TRUE) { // Mark the field instance for deletion. db_update('field_config_instance') ->fields(array('deleted' => 1)) ->condition('field_name', $instance['field_name']) ->condition('entity_type', $instance['entity_type']) ->condition('bundle', $instance['bundle']) ->execute(); // Clear the cache. field_cache_clear(); // Mark instance data for deletion. $field = field_info_field($instance['field_name']); module_invoke($field['storage']['module'], 'field_storage_delete_instance', $instance); // Let modules react to the deletion of the instance. module_invoke_all('field_delete_instance', $instance); // Delete the field itself if we just deleted its last instance. if ($field_cleanup && count($field['bundles']) == 0) { field_delete_field($field['field_name']); } } /** * @} End of "defgroup field_crud". */ /** * @defgroup field_purge Field API bulk data deletion * @{ * Clean up after Field API bulk deletion operations. * * Field API provides functions for deleting data attached to individual * entities as well as deleting entire fields or field instances in a single * operation. * * Deleting field data items for an entity with field_attach_delete() involves * three separate operations: * - Invoking the Field Type API hook_field_delete() for each field on the * entity. The hook for each field type receives the entity and the specific * field being deleted. A file field module might use this hook to delete * uploaded files from the filesystem. * - Invoking the Field Storage API hook_field_storage_delete() to remove * data from the primary field storage. The hook implementation receives the * entity being deleted and deletes data for all of the entity's bundle's * fields. * - Invoking the global Field Attach API hook_field_attach_delete() for all * modules that implement it. Each hook implementation receives the entity * being deleted and can operate on whichever subset of the entity's bundle's * fields it chooses to. * * These hooks are invoked immediately when field_attach_delete() is * called. Similar operations are performed for field_attach_delete_revision(). * * When a field, bundle, or field instance is deleted, it is not practical to * invoke these hooks immediately on every affected entity in a single page * request; there could be thousands or millions of them. Instead, the * appropriate field data items, instances, and/or fields are marked as deleted * so that subsequent load or query operations will not return them. Later, a * separate process cleans up, or "purges", the marked-as-deleted data by going * through the three-step process described above and, finally, removing * deleted field and instance records. * * Purging field data is made somewhat tricky by the fact that, while * field_attach_delete() has a complete entity to pass to the various deletion * hooks, the Field API purge process only has the field data it has previously * stored. It cannot reconstruct complete original entities to pass to the * deletion hooks. It is even possible that the original entity to which some * Field API data was attached has been itself deleted before the field purge * operation takes place. * * Field API resolves this problem by using "pseudo-entities" during purge * operations. A pseudo-entity contains only the information from the original * entity that Field API knows about: entity type, id, revision id, and * bundle. It also contains the field data for whichever field instance is * currently being purged. For example, suppose that the node type 'story' used * to contain a field called 'subtitle' but the field was deleted. If node 37 * was a story with a subtitle, the pseudo-entity passed to the purge hooks * would look something like this: * * @code * $entity = stdClass Object( * [nid] => 37, * [vid] => 37, * [type] => 'story', * [subtitle] => array( * [0] => array( * 'value' => 'subtitle text', * ), * ), * ); * @endcode * * See @link field Field API @endlink for information about the other parts of * the Field API. */ /** * Purges a batch of deleted Field API data, instances, or fields. * * This function will purge deleted field data in batches. The batch size * is defined as an argument to the function, and once each batch is finished, * it continues with the next batch until all have completed. If a deleted field * instance with no remaining data records is found, the instance itself will * be purged. If a deleted field with no remaining field instances is found, the * field itself will be purged. * * @param $batch_size * The maximum number of field data records to purge before returning. */ function field_purge_batch($batch_size) { // Retrieve all deleted field instances. We cannot use field_info_instances() // because that function does not return deleted instances. $instances = field_read_instances(array('deleted' => 1), array('include_deleted' => 1)); foreach ($instances as $instance) { // field_purge_data() will need the field array. $field = field_info_field_by_id($instance['field_id']); // Retrieve some entities. $query = new EntityFieldQuery(); $results = $query ->fieldCondition($field) ->entityCondition('bundle', $instance['bundle']) ->deleted(TRUE) ->range(0, $batch_size) ->execute(); if ($results) { foreach ($results as $entity_type => $stub_entities) { field_attach_load($entity_type, $stub_entities, FIELD_LOAD_CURRENT, array('field_id' => $field['id'], 'deleted' => 1)); foreach ($stub_entities as $stub_entity) { // Purge the data for the entity. field_purge_data($entity_type, $stub_entity, $field, $instance); } } } else { // No field data remains for the instance, so we can remove it. field_purge_instance($instance); } } // Retrieve all deleted fields. Any that have no instances can be purged. $fields = field_read_fields(array('deleted' => 1), array('include_deleted' => 1)); foreach ($fields as $field) { $instances = field_read_instances(array('field_id' => $field['id']), array('include_deleted' => 1)); if (empty($instances)) { field_purge_field($field); } } } /** * Purges the field data for a single field on a single pseudo-entity. * * This is basically the same as field_attach_delete() except it only applies * to a single field. The entity itself is not being deleted, and it is quite * possible that other field data will remain attached to it. * * @param $entity_type * The type of $entity; e.g. 'node' or 'user'. * @param $entity * The pseudo-entity whose field data is being purged. * @param $field * The (possibly deleted) field whose data is being purged. * @param $instance * The deleted field instance whose data is being purged. */ function field_purge_data($entity_type, $entity, $field, $instance) { // Each field type's hook_field_delete() only expects to operate on a single // field at a time, so we can use it as-is for purging. $options = array('field_id' => $instance['field_id'], 'deleted' => TRUE); _field_invoke('delete', $entity_type, $entity, $dummy, $dummy, $options); // Tell the field storage system to purge the data. module_invoke($field['storage']['module'], 'field_storage_purge', $entity_type, $entity, $field, $instance); // Let other modules act on purging the data. foreach (module_implements('field_attach_purge') as $module) { $function = $module . '_field_attach_purge'; $function($entity_type, $entity, $field, $instance); } } /** * Purges a field instance record from the database. * * This function assumes all data for the instance has already been purged, and * should only be called by field_purge_batch(). * * @param $instance * The instance record to purge. */ function field_purge_instance($instance) { db_delete('field_config_instance') ->condition('id', $instance['id']) ->execute(); // Notify the storage engine. $field = field_info_field_by_id($instance['field_id']); module_invoke($field['storage']['module'], 'field_storage_purge_instance', $instance); // Clear the cache. field_info_cache_clear(); // Invoke external hooks after the cache is cleared for API consistency. module_invoke_all('field_purge_instance', $instance); } /** * Purges a field record from the database. * * This function assumes all instances for the field has already been purged, * and should only be called by field_purge_batch(). * * @param $field * The field record to purge. */ function field_purge_field($field) { $instances = field_read_instances(array('field_id' => $field['id']), array('include_deleted' => 1)); if (count($instances) > 0) { throw new FieldException(t('Attempt to purge a field @field_name that still has instances.', array('@field_name' => $field['field_name']))); } db_delete('field_config') ->condition('id', $field['id']) ->execute(); // Notify the storage engine. module_invoke($field['storage']['module'], 'field_storage_purge_field', $field); // Clear the cache. field_info_cache_clear(); // Invoke external hooks after the cache is cleared for API consistency. module_invoke_all('field_purge_field', $field); } /** * @} End of "defgroup field_purge". */