CakePHP で任意のステータスコードで JSON レスポンスを返すサンプル

curl

$ curl -X POST http://localhost:8765/api/posts | jq .
{
  "status": "invalid"
}

PostsController.php

<?php


namespace App\Controller;


class PostsController extends AppController
{
    public function initialize()
    {
        parent::initialize();
        // Accept ヘッダの指定によらず JSON を返す
        $this->viewBuilder()->setClassName('Json');
    }

    public function add()
    {
        $this->set([
            'response' => ['status' => 'invalid'],
            '_serialize' => 'response'
        ]);
        $response = $this->response->withStatus(400);
        $this->setResponse($response);
        return $this->render();
    }
}

routes.php

Router::scope('/api', function(RouteBuilder $routes) {
    // Resources は fallback が効かないので inflect を指定する
    $routes->resources('Posts', ['inflect' => 'dasherize']);
});