Symfony - how to call next service in chain - php

Question

I want to implement chain of responsibility pattern for authorization in my app. I have created four different chain services for authorization and they depends on which routes user want to access. I have a problem with chaining services. I want to chain services without explicitly naming them. For example:
class Authorization1:
public function auth($request){
if (isThisRoute){
$this->authorize($request);
}
$this->authorization2->authorize($request);
}
I want to know how can i replace last line: $this->authorization2->authorize($request); with $this->chain->authorize($request); so chain of responsibility pattern can be implemented completly.

Answer 1

Your code looks like Laravel middleware code.
Try to learn it: https://refactoring.guru/design-patterns/chain-of-responsibility
If your really want to use Chain of Responsibility instead of Strategy for your four different services it can look like the follow code (PHP v8.0).
Interface for chains
interface AuthorizationRequestHandlerInterface
{
public function auth(Request $request): bool;
// Option 2
public function setNext(AuthorizationRequestHandlerInterface $handler): void;
}
A handler for a condition or state
class Authorization1 implements AuthorizationRequestHandlerInterface
{
// Option 1
public function __construct(private AuthorizationRequestHandlerInterface $handler)
{
}
// Option 2
public function setNext(AuthorizationRequestHandlerInterface $handler): void
{
$this->handler = $handler;
}
public function auth(Request $request): bool
{
if (isThisRoute) {
// Check permissions here or call your private or protected method
return $this->authorize($request);
}
// Option 1: Call the next handler
return $this->handler->auth($request);
// Option 2: Call the next handler if it exists
return $this->handler ? $this->handler->auth($request) : false;
}
private function authorize(Request $request): bool
{
$result = false;
// Your code
return $result;
}
}
Other handlers looks like previous one.
You may do any operations with your object and return any type of value, but this example uses bool.
You should prepare configuration of your services in services.yml or another way which you use.
At the end PHP code may look like that:
// Initialization: Option 1
$authNull = new AuthNull();
$auth1 = new Authorization1($authNull);
$auth2 = new Authorization2($auth1);
$auth3 = new Authorization3($auth2);
return $auth3;
// Initialization: Option 2
$auth1 = new Authorization1($authNull);
$auth2 = new Authorization2($auth1);
$auth3 = new Authorization3($auth2);
$auth1->setNext($auth2);
$auth2->setNext($auth3);
// In this way you must add the `setNext` method and use its value as `handler` instead of that constructor value.
return $auth1;
// ...
// A class that has the main handler, like AbstractGuardAuthenticator, Controller, ArgumentResolver, ParamConverter, Middleware, etc.
if ($auth->handle($request)) {
// when it is authorizable, continues the request
} else {
// when it isn't authorizable, throws Exception, for example
}
// Different handling order that depends on the options.
// Option 1: Auth3 -> Auth2 -> Auth1 -> AuthNull
// Option 2: Auth1 -> Auth2 -> Auth3
As #alexcm mentioned, you should read some Symfony information:
https://symfony.com/doc/current/security/voters.html
https://symfony.com/doc/current/routing.html
https://symfony.com/doc/current/configuration.html
https://symfony.com/doc/current/components/http_kernel.html
https://symfony.com/doc/current/controller/argument_value_resolver.html
https://symfony.com/bundles/SensioFrameworkExtraBundle/current/annotations/converters.html