register_rest_field( string|array $object_type, string $attribute, array $args = array() )

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$object_typestring|array

Object(s) the field is being registered to, "post"|"term"|"comment" etc.

$attributestring

The attribute name.

$argsarrayoptional

An array of arguments used to handle the registered field.Default: array()

• $get_callbackcallable|null

  Optional. The callback function used to retrieve the field value. Default is 'null', the field will not be returned in the response. The function will be passed the prepared object data.

• $update_callbackcallable|null

  Optional. The callback function used to set and update the field value. Default is 'null', the value cannot be set or updated. The function will be passed the model object, like WP_Post.

• $schemaarray|nulldefault: is 'null', no schema entry will be returned

  Optional. The schema for this field.

Performance profile

How much work a call to register_rest_field() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Light

Touches nothing outside its own arguments.

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

14–15

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 19.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What one call costs · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost register_rest_field() can have, taken from its control-flow graph on PHP 8.5.

Uses · 1

• wp_parse_args()Merges user defined arguments into defaults array.

Used by · 1

• WP_REST_Meta_Fields::register_field()Registers the meta field.

Source code

View on Trac ↗View on GitHub ↗

182function register_rest_field( $object_type, $attribute, $args = array() ) {183	global $wp_rest_additional_fields;184 185	$defaults = array(186		'get_callback'    => null,187		'update_callback' => null,188		'schema'          => null,189	);190 191	$args = wp_parse_args( $args, $defaults );192 193	$object_types = (array) $object_type;194 195	foreach ( $object_types as $object_type ) {196		$wp_rest_additional_fields[ $object_type ][ $attribute ] = $args;197	}198}

Changelog

Introduced in 4.7.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/rest-api.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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