函数原型
register_meta( string $object_type, string $meta_key, array $args, string|array $deprecated = null ): bool
函数描述
Registers a meta key.
是否弃用
未弃用
函数参数
-
$object_type
string
Required - Type of object metadata is for. Accepts
'post','comment','term','user', or any other object type with an associated meta table. -
$meta_key
string
Required - Meta key to register.
-
$args
array
Required - Data used to describe the meta key when registered.
object_subtypestringA subtype; e.g. if the object type is "post", the post type. If left empty, the meta key will be registered on the entire object type. Default empty.typestringThe type of data associated with this meta key.
Valid values are'string','boolean','integer','number','array', and'object'.descriptionstringA description of the data attached to this meta key.singleboolWhether the meta key has one value per object, or an array of values per object.defaultmixedThe default value returned from get_metadata() if no value has been set yet.
When using a non-single meta key, the default value is for the first entry.
In other words, when calling get_metadata() with$singleset tofalse, the default value given here will be wrapped in an array.sanitize_callbackcallableA function or method to call when sanitizing$meta_keydata.auth_callbackcallableOptional. A function or method to call when performing edit_post_meta, add_post_meta, and delete_post_meta capability checks.show_in_restbool|arrayWhether data associated with this meta key can be considered public and should be accessible via the REST API. A custom post type must also declare support for custom fields for registered meta to be accessible via REST.
When registering complex meta values this argument may optionally be an array with'schema'or'prepare_callback'keys instead of a boolean.
-
$deprecated
string|array
Optional - Deprecated. Use
$argsinstead.Default:
null
函数返回值
bool True if the meta key was successfully registered in the global array, false if not.
Registering a meta key with distinct sanitize and auth callbacks will fire those callbacks, but will not add to the global registry.
函数位置
File: wp-includes/meta.php.
函数源码
function register_meta( $object_type, $meta_key, $args, $deprecated = null ) {
global $wp_meta_keys;
if ( ! is_array( $wp_meta_keys ) ) {
$wp_meta_keys = array();
}
$defaults = array(
'object_subtype' => '',
'type' => 'string',
'description' => '',
'default' => '',
'single' => false,
'sanitize_callback' => null,
'auth_callback' => null,
'show_in_rest' => false,
);
// There used to be individual args for sanitize and auth callbacks.
$has_old_sanitize_cb = false;
$has_old_auth_cb = false;
if ( is_callable( $args ) ) {
$args = array(
'sanitize_callback' => $args,
);
$has_old_sanitize_cb = true;
} else {
$args = (array) $args;
}
if ( is_callable( $deprecated ) ) {
$args['auth_callback'] = $deprecated;
$has_old_auth_cb = true;
}
/**
* Filters the registration arguments when registering meta.
*
* @since 4.6.0
*
* @param array $args Array of meta registration arguments.
* @param array $defaults Array of default arguments.
* @param string $object_type Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user',
* or any other object type with an associated meta table.
* @param string $meta_key Meta key.
*/
$args = apply_filters( 'register_meta_args', $args, $defaults, $object_type, $meta_key );
unset( $defaults['default'] );
$args = wp_parse_args( $args, $defaults );
// Require an item schema when registering array meta.
if ( false !== $args['show_in_rest'] && 'array' === $args['type'] ) {
if ( ! is_array( $args['show_in_rest'] ) || ! isset( $args['show_in_rest']['schema']['items'] ) ) {
_doing_it_wrong( __FUNCTION__, __( 'When registering an "array" meta type to show in the REST API, you must specify the schema for each array item in "show_in_rest.schema.items".' ), '5.3.0' );
return false;
}
}
$object_subtype = ! empty( $args['object_subtype'] ) ? $args['object_subtype'] : '';
// If `auth_callback` is not provided, fall back to `is_protected_meta()`.
if ( empty( $args['auth_callback'] ) ) {
if ( is_protected_meta( $meta_key, $object_type ) ) {
$args['auth_callback'] = '__return_false';
} else {
$args['auth_callback'] = '__return_true';
}
}
// Back-compat: old sanitize and auth callbacks are applied to all of an object type.
if ( is_callable( $args['sanitize_callback'] ) ) {
if ( ! empty( $object_subtype ) ) {
add_filter( "sanitize_{$object_type}_meta_{$meta_key}_for_{$object_subtype}", $args['sanitize_callback'], 10, 4 );
} else {
add_filter( "sanitize_{$object_type}_meta_{$meta_key}", $args['sanitize_callback'], 10, 3 );
}
}
if ( is_callable( $args['auth_callback'] ) ) {
if ( ! empty( $object_subtype ) ) {
add_filter( "auth_{$object_type}_meta_{$meta_key}_for_{$object_subtype}", $args['auth_callback'], 10, 6 );
} else {
add_filter( "auth_{$object_type}_meta_{$meta_key}", $args['auth_callback'], 10, 6 );
}
}
if ( array_key_exists( 'default', $args ) ) {
$schema = $args;
if ( is_array( $args['show_in_rest'] ) && isset( $args['show_in_rest']['schema'] ) ) {
$schema = array_merge( $schema, $args['show_in_rest']['schema'] );
}
$check = rest_validate_value_from_schema( $args['default'], $schema );
if ( is_wp_error( $check ) ) {
_doing_it_wrong( __FUNCTION__, __( 'When registering a default meta value the data must match the type provided.' ), '5.5.0' );
return false;
}
if ( ! has_filter( "default_{$object_type}_metadata", 'filter_default_metadata' ) ) {
add_filter( "default_{$object_type}_metadata", 'filter_default_metadata', 10, 5 );
}
}
// Global registry only contains meta keys registered with the array of arguments added in 4.6.0.
if ( ! $has_old_auth_cb && ! $has_old_sanitize_cb ) {
unset( $args['object_subtype'] );
$wp_meta_keys[ $object_type ][ $object_subtype ][ $meta_key ] = $args;
return true;
}
return false;
}
源码链接
变更日志
| Version | Description |
|---|---|
| 5.5.0 | The $default argument was added to the arguments array. |
| 5.3.0 | Valid meta types expanded to include "array" and "object". |
| 4.9.8 | The $object_subtype argument was added to the arguments array. |
| 4.6.0 | Modified to support an array of data to attach to registered meta keys. Previous arguments for $sanitize_callback and $auth_callback have been folded into this array. |
| 3.3.0 | Introduced. |

