FOSRestBundle: partial response in function of attributes asked in the request - php

Question

Context
I found a lot of questions about partial API response with FOSRest and all the answers are based on the JMS serializer options (exlude, include, groups, etc). It works fine but I try to achieve something less "static".
Let's say I have a user with the following attributes: id username firstname lastname age sex
I retrieve this user with the endpoint GET /users/{id} and the following method:
/**
* #View
*
* GET /users/{id}
* #param integer $user (uses ParamConverter)
*/
public function getUserAction(User $user) {
return $user;
}
The method returns the user with all his attributes.
Now I want to allow something like that: GET /users/{id}?attributes=id,username,sex
Question
Did I missed a functionality of FOSRestBUndle, JMSserializer or SensioFrameworkExtraBundle to achieve it automatically? An annotation, a method, a keyword in the request or something else?
Otherwise, what is the best way to achieve it?
Code
I thought to do something like that:
/**
* #View
* #QueryParam(name="attributes")
*
* GET /users/{id}
*
* #param integer $user (uses ParamConverter)
*/
public function getUserAction(User $user, $attributes) {
$groups = $attributes ? explode(",", $attributes) : array("Default");
$view = $this->view($user, 200)
->setSerializationContext(SerializationContext::create()->setGroups($groups));
return $this->handleView($view);
}
And create a group for each attribute:
use JMS\Serializer\Annotation\Groups;
class User {
/** #Groups({"id"}) */
protected $id;
/** #Groups({"username"}) */
protected $username;
/** #Groups({"firstname"}) */
protected $firstname;
//etc
}

Answer 1

My implementation based on Igor's answer:
ExlusionStrategy:
use JMS\Serializer\Exclusion\ExclusionStrategyInterface;
use JMS\Serializer\Metadata\ClassMetadata;
use JMS\Serializer\Metadata\PropertyMetadata;
use JMS\Serializer\Context;
class FieldsExclusionStrategy implements ExclusionStrategyInterface {
private $fields = array();
public function __construct(array $fields) {
$this->fields = $fields;
}
public function shouldSkipClass(ClassMetadata $metadata, Context $navigatorContext) {
return false;
}
public function shouldSkipProperty(PropertyMetadata $property, Context $navigatorContext) {
if (empty($this->fields)) {
return false;
}
if (in_array($property->name, $this->fields)) {
return false;
}
return true;
}
}
Controller:
/**
* #View
* #QueryParam(name="fields")
*
* GET /users/{id}
*
* #param integer $user (uses ParamConverter)
*/
public function getUserAction(User $user, $fields) {
$context = new SerializationContext();
$context->addExclusionStrategy(new FieldsExclusionStrategy($fields ? explode(',', $fields) : array()));
return $this->handleView($this->view($user)->setSerializationContext($context));
}
Endpoint:
GET /users/{id}?fields=id,username,sex

Answer 2

You can do it like that through groups, as you've shown. Maybe a bit more elegant solution would be to implement your own ExclusionStrategy. #Groups and other are implementations of ExclusionStrategyInterface too.
So, say you called your strategy SelectFieldsStrategy. Once you implement it, you can add it to your serialization context very easy:
$context = new SerializationContext();
$context->addExclusionStrategy(new SelectFieldsStrategy(['id', 'name', 'someotherfield']));