How to extend the WordPress Rest API

and do magic stuff

Created by Daniele Scasciafratte / Mte90Net

Now imagine

You have your amazing

custom post type

with custom fields

and you need a mobile app

and access that data also from

another website

How can you achieve that stuff?

Do you want an example?

mte90.net/wp-json

Add a post type in the Rest API

					add_action( 'init', 'my_book_cpt' );
function my_book_cpt() {

$args = array(
	'show_in_rest'       => true,
	/** 'rest_base'          => 'books',
	'rest_controller_class' => 'WP_REST_Posts_Controller' **/
);

register_post_type( 'book', $args );
					

Add an existing post type in the Rest API

					add_action( 'init', 'my_custom_post_type_rest_support', 25 );
function my_custom_post_type_rest_support() {
  	global $wp_post_types;
  
  	$post_type_name = 'book';
  	if( isset( $wp_post_types[ $post_type_name ] ) ) {
  		$wp_post_types[$post_type_name]->show_in_rest = true;
  		$wp_post_types[$post_type_name]->rest_base = $post_type_name;
  		$wp_post_types[$post_type_name]->rest_controller_class = 'WP_REST_Posts_Controller';
  	}
}
					

Add custom field to the Rest API

					add_action( 'rest_api_init', 'slug_register_book' );
function slug_register_starship() {
    register_rest_field( 'post',
        'book',
        array(
            'get_callback'    => 'slug_get_meta',
            'update_callback' => 'slug_update_book',
            'schema'          => null,
        )
    );
}

function slug_get_book( $object, $field_name, $request ) {
    return get_post_meta( $object[ 'id' ], $field_name );
}

function slug_update_book( $value, $object, $field_name ) {
    if ( ! $value || ! is_string( $value ) ) {
        return;
    }
    return update_post_meta( $object->ID, $field_name, strip_tags( $value ) );
}

					

Add a custom endpoint

add_action( 'rest_api_init', function () {
	register_rest_route( 'myplugin/v1', '/author/(?P< id>\d+)', array(
		'methods' => 'GET',
		'callback' => 'get_last_post_title_of_author',
	) );
} );
function get_last_post_title_of_author( $data ) {
	$posts = get_posts( array(
		'author' => $data['id'],
	) );

	if ( empty( $posts ) ) {
		return null;
	}

	return $posts[0]->post_title;
}
					

THE END

- http://v2.wp-api.org/