rest_api_init │ action-hook │ WP 4.4.0

Fires at the beginning of REST API request processing (when serving the REST request is being prepared).

New REST routes should be registered while this hook fires (see register_rest_route()) to ensure that they are available when a REST request is processed.

Usage

add_action( 'rest_api_init', 'wp_kama_rest_api_init_action' );

/**
 * Function for `rest_api_init` action-hook.
 * 
 * @param WP_REST_Server $wp_rest_server Server object.
 *
 * @return void
 */
function wp_kama_rest_api_init_action( $wp_rest_server ){
	// action...
}

$wp_rest_server(WP_REST_Server)

The REST server object.

Examples

#1 Create a new endpoint for a plugin

add_action( 'rest_api_init', function(){

	register_rest_route( 'myplug/v2', '/posts', array(
		'methods'  => 'GET',
		'callback' => 'myplug_get_post_items',
	) );

} );

function myplug_get_post_items(){
	$posts = get_posts( array (
		'post_status' => 'publish',
		'numberposts' => 100
	) ) ;

	$items = array();

	foreach( $posts as $post ){
		$items[] = array(
			'id'      => $post->ID,
			'title'   => $post->post_title,
			'author'  => get_the_author_meta( 'display_name', $post->post_author ),
			'content' => apply_filters( 'the_content', $post->post_content ),
			'teaser'  => $post->post_excerpt
		);
	}

	return $items;
}

After installing this code, the endpoint:

GET http://example.com/wp-json/myplug/v2/posts

Will return the site's posts in the specified format.