having trouble with slimframework's Immutable responses - php

Question

I am trying to setup a project for an API using slim framework version 3, I don't know who made the PSR-7 and marked the response object as immutable, I don't see any use in that (IMHO. please explain me if I am wrong). Things were much easier when it was slim 2. Now I came back to slim after a long time.
I have a route which is a post method, I am getting data and saving it to the database and I am trying to send 201 as the response code. all the examples and the documentation is showing you how can you change the response code within the index.php file itself, But I am trying to change it from a response builder which I have tried to use the factory pattern to provide different responses. The problem is the response code always stays 200 no matter what function I call from the response builder class. I tried many forums and different ways of slim but still couldn't able to pull this up. I almost decided to give up on a PSR 7 router implementation and going to implement my own routing solution. But I remember not to reinvent the wheel again so I came here as a final try. Below is the code.
the route definition
$app->post('/users', function(ServerRequestInterface $req, ResponseInterface $res) {
$data = $req->getParsedBody();
$model = new \Apex\Models\User(ApexDB::getInstance());
$jsonBuilder = ApexResponse::getBuilder('JSON', $res);
$control = new \Apex\Controllers\User($model, $jsonBuilder);
$control->create($data);
});
the controller method (abstract I am just setting it up)
public function create($data) {
if($this->model->save($data)) {
$this->response->build($data,201);
} else {
$this->response->build('error',400);
}
}
the JSON builder
class JSONBuilder implements Response
{
public $response;
public function __construct($response)
{
$this->response = $response;
}
public function build($data, $status)
{
$response = $this->response->withJSON($data,$status);
return $response;
}
}
can anyone point me in the right direction?

Answer 1

The PSR-7 decision to use immutable objects for Request and Response is documented in the Why value objects? section of the Meta document.
With Slim 3, you must always return a Response instance from the controller method.
$app->post('/users', function(ServerRequestInterface $req, ResponseInterface $res) {
$data = $req->getParsedBody();
$model = new \Apex\Models\User(ApexDB::getInstance());
$jsonBuilder = ApexResponse::getBuilder('JSON', $res);
$control = new \Apex\Controllers\User($model, $jsonBuilder);
return $control->create($data);
});
and then your create method also needs to return the $response:
public function create($data) {
if($this->model->save($data)) {
$this->response->build($data,201);
} else {
$this->response->build('error',400);
}
return $this->response;
}
It should then work.
However, you can use the controller method directly from the route declaration and avoid the need for a the closure:
$app->post('/users', `Apex\Controllers\User::create`);
The controller's create method would then look like this:
namespace Apex\Controllers;
class User
{
public function create($request, $response)
{
$data = $request->getParsedBody();
$model = new \Apex\Models\User(ApexDB::getInstance());
$jsonBuilder = ApexResponse::getBuilder('JSON', $response);
if ($model->save($data)) {
$response = $jsonBuilder->build($data, 201);
} else {
$response = $jsonBuilder->build('error', 400);
}
return $response;
}
}
Finally, consider rka-content-type-renderer instead of JsonBuilder, though maybe it does more than you've shown.
Update:
Ideally you'd use constructor injection to inject the User model into the controller. To do this:
Update your controller:
namespace Apex\Controllers;
use Apex\Models\User as UserModel;
class User
{
protected $userModel;
public function __construct(UserModel $userModel)
{
$this->userModel = $userModel;
}
public function create($request, $response)
{
$data = $request->getParsedBody();
$jsonBuilder = ApexResponse::getBuilder('JSON', $response);
if ($this->userModel->save($data)) {
$response = $jsonBuilder->build($data, 201);
} else {
$response = $jsonBuilder->build('error', 400);
}
return $response;
}
}
Write a factory for the Pimple dependency injection container:
$container = $app->getContainer();
$container['Apex\Controllers\User'] = function ($c) {
$userModel = new \Apex\Models\User(ApexDB::getInstance());
return new \ApexController\User($userModel);
};