register_post_meta() WP 4.9.8

Registers a meta key for posts (post custom field).

It is a wrapper for the register_meta function for easy registration of post meta-fields.

No Hooks.

Return

true|false. True if the meta key was successfully registered, false if not.

Usage

register_post_meta( $post_type, $meta_key, $args );

$post_type(string) (required)

Post type to register a meta key for. Pass an empty string to register the meta key across all existing post types.

$meta_key(string) (required)

The meta key to register.

$args(array) (required)

Data used to describe the meta key when registered. See register_meta() for a list of supported arguments.

#1 Register a meta-field for pages only

register_post_meta( 'page', 'my_meta_key', array(
	// Add to REST response
	'show_in_rest' => true,
	// Process the value of the field when saving it to the database, function absint()
	'sanitize_callback' => 'absint',
) );

Now the meta-field with the key my_meta_key will be registered for pages only.

The same can be done with register_meta(), like this:

register_meta( 'post', 'my_meta_key', array(
	'object_subtype' => 'page', // post type
	'show_in_rest' => true,
	'sanitize_callback' => 'absint',
) );

#2 More examples

See the register_meta() function for more examples and usage features.

Changelog

Code of register_post_meta() register post meta ^{WP 5.8.1}

function register_post_meta( $post_type, $meta_key, array $args ) {
	$args['object_subtype'] = $post_type;

	return register_meta( 'post', $meta_key, $args );
}

Related Functions

WP extension (enhancement)

Metadatas (any)