Extending The WordPress REST

APIJosh Pollock

Hi, I'm Josh

Slides: JoshPress.net/extending-rest-api-talk

What We Are Covering

Extending The Default Responses

v2.wp-api.org/extending/modifyi

ng/

Creating Your Own Endpoints

v2.wp-api.org/extending/adding/

We're Skipping To The Back of The Book:)

Download: wpeng.in/wp-api-ebook/

Let's Talk About Defaults

Why Extend The Defaults?

Are endpoints of a default endpoint close, but missing a field?Combine POST requests.

add_filter( 'the_content', function( $content ) { …

add_filter( 'template_includes', function( $template ) { ...

Why Make Your Own?

● Unique data sets -- custom queries, custom tables, wrapping existing classes.

● Just the data you need.● Replace admin-ajax$query = new WP_Query( $args );

$collection = new my_class( $params );

global $wpdb;

add_rewrite_rule('^leaf/([0-9]+)/?', 'index.php?page_id=$matches[1]', 'top');

Anatomy Of A REST Request

WP_REST_SERVER ??WP_REST_Request WP_REST_Response

Extending Defaults

Customizing Default Routes

● Add fields to response○ Custom field or any other data

● Applies to all read and/or write endpoints of route.

Meet register_api_field()

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

● Adds fields to one or more response● Arguments:

○ Object (post type name or "terms", "meta", "user" or "comments" )

○ Name of field○ Args

■ Read Callback■ Write Callback■ Schema Callback

Example Handlersfunction slug_get_meta_field( $object, $field_name, $request ) {

return get_post_meta( $object[ 'id' ], $field_name );

}

public function slug_update_meta( $value, $object, $field_name ) { if ( ! $value || ! is_string( $value ) ) { return; }

return update_post_meta( $object->ID, $field_name, strip_tags( $value ) );

}

Example Registration

add_action( 'rest_api_init', 'slug_register_spaceship' );function slug_register_spaceship() { register_api_field( 'post', 'starship', array( 'get_callback' => slug_get_meta_field, 'update_callback' => slug_update_meta_field, 'schema' => null, ) );}

Adding Your Own Endpoints

Anatomy Of A REST Request

WP_REST_SERVER Your RouteWP_REST_Request WP_REST_Response

Request -> Callback -> Response

Check Permission Validate Fields Sanitize Fields

Callback

Response

Meet register_rest_route()

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

Adds a collection of routes.add_action( 'rest_api_init', function () { register_rest_route( 'myplugin/v1', '/author/(?P<id>\d+)', array( 'methods' => 'GET', 'callback' => 'my_awesome_func', ) );} );

Namespacing & Versioning

register_rest_route() Defines

● Endpoints For Route● Permissions for endpoints● Transport methods for endpoints● Fields for endpoints● Callback for endpoints● Schema

Endpoint URL

public function the_route() { register_rest_route( 'swp_api', '/search',

array( ) );

}Namespace

Route

Transport Methodpublic function the_route() { register_rest_route( 'swp_api', '/search',

array( 'methods' => \WP_REST_Server::READABLE, )

);}

GET

Permissionspublic function the_route() { register_rest_route( 'swp_api', '/search',

array( 'methods' => \WP_REST_Server::READABLE, 'permission_callback' => array( $this, 'permissions_check' ) ));

}

Permissionspublic function permissions_check( $request ) {

$allowed = apply_filters( 'cwp_swp_api_allow_query', true, $request ); return (bool) $allowed;

}public function permissions_check( $request ) {

return current_user_can( 'something' );}

Standard WordPress Permissions/ Authentication!!!!!!!!!

Fieldspublic function the_route() { register_rest_route( 'swp_api', '/search', array(

'methods' => \WP_REST_Server::READABLE, 'permission_callback' => array( $this, 'permissions_check' ), 'args' => $this->the_args(),

) );}

Fields $args = array(

's' => array(

'default' => '', 'sanitize_callback' => 'sanitize_text_field',

),

'engine' => array(

'default' => 'default', 'sanitize_callback' => 'sanitize_text_field', 'validate_callback' => array( $this, 'validate_engine' ),

),

'page' => array(

'default' => 1,

'sanitize_callback' => 'absint', ),

);

Callbackpublic function the_route() { register_rest_route( 'swp_api', '/search', array( 'methods' => \WP_REST_Server::READABLE, 'permission_callback' => array( $this, 'permissions_check' ), 'args' => $this->the_args(), 'callback' => array( $this, 'callback' ), ) );}

Callbackpublic function callback( $request ) {

$params = $request->get_params();$cb_class = new class_that_does_something( $params );$results = $cb_class->get_results();if( is_array( $results ) {

return rest_ensure_response( $results, 200 );}elseif( is_wp_error( $results ) ) {

return rest_ensure_response( $results, 500 );}else{

return rest_ensure_response( __( 'FAIL!', 'text-domain' ), 500 );}

}

Response

Should be either:● An instance of WP_REST_Response● An instance of WP_Error

rest_ensure_response( $data, $code, $headers );

You're Ready To Learn MoreJoshPress.net/extending-rest-api-talkwpeng.in/wp-api-ebook/

That's About It

JoshPress.netCalderaWP.com@Josh412

Josh Pollock