WP REST API Extending existing controller

Question

My ideia is to get the list of categories but with only the fields that I need. The request parameters (exclude, include, order, per_page, etc.) should work as when using REST API.

So I am trying to extending the WP_REST_Terms_Controller.php controller. Here is the code I have so far:

<?php

if ( ! class_exists( 'WP_REST_Controller' ) ) {
    require_once ABSPATH. 'wp-content/plugins/rest-api/lib/endpoints/' . '/class-wp-rest-controller.php';
}
if ( ! class_exists( 'WP_REST_Taxonomies_Controller' ) ) {
    require_once ABSPATH. 'wp-content/plugins/rest-api/lib/endpoints/' . '/class-wp-rest-terms-controller.php';
}


class MyPlugin_Categories_Controller extends WP_REST_Terms_Controller
{

    public function __construct() {
        parent::__construct('category');
    }

    public function register_routes() {
        $version = '1';
        $namespace = 'myplugin-api/v' . $version;
        $base = 'categories';
        register_rest_route( $namespace, '/' . $base, array(
            array(
                'methods'         => WP_REST_Server::READABLE,
                'callback'        => array( $this, 'get_items' ),
                'args'            => array(

                ),
            ),
        ) );
    }

    /**
     * Get a collection of items
     *
     * @param WP_REST_Request $request Full data about the request.
     * @return WP_Error|WP_REST_Response
     */
    public function get_items( $request ) {

        var_dump($request);
        $items = parent::get_items($request);
        $data = array();
        foreach( $items as $item ) {
            $itemdata = $this->prepare_item_for_response( $item, $request );
            $data[] = $this->prepare_response_for_collection( $itemdata );
        }

        return $data;
    }

}

When the getItem() method executed, the following error is raised:

( ! ) Warning: Division by zero in E:\wamp64\www\wordpress\wp-content\plugins\rest-api\lib\endpoints\class-wp-rest-terms-controller.php on line 181

This is related to the execution of: $items = parent::get_items($request);

The problem seems to be the $request object as it does not contain the default properties (exclude, include, order, per_page, etc.).

Here is the dump of the $request:

E:\wamp64\www\wordpress\wp-content\plugins\myplugin-api\class-myplugin-categories-controller.php:46: object(WP_REST_Request)[65]   protected 'method' => string 'GET' (length=3)   protected 'params' => 
    array (size=6)
      'URL' => 
        array (size=0)
          empty
      'GET' => 
        array (size=0)
          empty
      'POST' => 
        array (size=0)
          empty
      'FILES' => 
        array (size=0)
          empty
      'JSON' => null
      'defaults' => 
        array (size=0)
          empty   protected 'headers' => 
    array (size=8)
      'host' => 
        array (size=1)
          0 => string 'localhost:8080' (length=14)
      'connection' => 
        array (size=1)
          0 => string 'keep-alive' (length=10)
      'cache_control' => 
        array (size=1)
          0 => string 'no-cache' (length=8)
      'user_agent' => 
        array (size=1)
          0 => string 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36' (length=114)
      'postman_token' => 
        array (size=1)
          0 => string '9c1726a9-b4ee-1d69-630f-c05bf1e85557' (length=36)
      'accept' => 
        array (size=1)
          0 => string '*/*' (length=3)
      'accept_encoding' => 
        array (size=1)
          0 => string 'gzip, deflate, sdch, br' (length=23)
      'accept_language' => 
        array (size=1)
          0 => string 'en-US,en;q=0.8,pt-PT;q=0.6,pt;q=0.4' (length=35)   protected 'body' => string '' (length=0)   protected 'route' => string '/myplugin-api/v1/categories' (length=27)   protected 'attributes' => 
    array (size=6)
      'methods' => 
        array (size=1)
          'GET' => boolean true
      'accept_json' => boolean false
      'accept_raw' => boolean false
      'show_in_index' => boolean true
      'args' => 
        array (size=0)
          empty
      'callback' => 
        array (size=2)
          0 => 
            object(MyPlugin_Categories_Controller)[67]
              ...
          1 => string 'get_items' (length=9)   protected 'parsed_json' => boolean false   protected 'parsed_body' => boolean false

What am I doing wrong?

I'm new in php so probably I'm missing something obvious.

Answer 1

After struggling a bit with this, I managed to send the result as I wanted:

<?php

if ( ! class_exists( 'WP_REST_Controller' ) ) {
    require_once ABSPATH. 'wp-content/plugins/rest-api/lib/endpoints/' . '/class-wp-rest-controller.php';
}
if ( ! class_exists( 'WP_REST_Taxonomies_Controller' ) ) {
    require_once ABSPATH. 'wp-content/plugins/rest-api/lib/endpoints/' . '/class-wp-rest-terms-controller.php';
}


class MyPlugin_Categories_Controller extends WP_REST_Terms_Controller
{

    public function __construct() {
        parent::__construct('category');
    }

    public function register_routes() {
        $version = '1';
        $namespace = 'myplugin-api/v' . $version;
        $base = 'categories';
        register_rest_route( $namespace, '/' . $base, array(
            array(
                'methods'         => WP_REST_Server::READABLE,
                'callback'        => array( $this, 'get_items' ),
                'args'            => parent::get_collection_params(),
            ),
        ) );
        register_rest_route( $namespace, '/' . $base . '/schema', array(
            'methods'         => WP_REST_Server::READABLE,
            'callback'        => array( $this, 'get_public_item_schema' ),
        ) );
    }

    /**
     * Get a collection of items
     *
     * @param WP_REST_Request $request Full data about the request.
     * @return WP_Error|WP_REST_Response
     */
    public function get_items( $request ) {

        $items = parent::get_items($request);

        if ( is_wp_error($items) ) {
            return $items;
        }

        $response = array();
        foreach( $items->get_data() as $item ) {
            $itemdata = $this->get_item_for_response( $item, $request );
            array_push($response,$itemdata);
        }

        $to_return = new WP_REST_Response($response,200);
        $to_return->set_headers($items->get_headers());
        return $to_return;
    }

    public function get_item_for_response( $item ) {
        $smalleritem = array();
        $smalleritem["id"] = $item["id"];
        $smalleritem["name"] = $item["name"];
        $smalleritem["count"] = $item["count"];
        return $smalleritem;
    }

}