How to update a Doctrine Entity from a serialized JSON?

Question

We are using Symfony2 to create an API. When updating a record, we expect the JSON input to represent a serialized updated entity. The JSON data will not contain some fields (for instance, CreatedAt should be set only once when the entity is created - and never updated). For instance, here is an example JSON PUT request:

{"id":"1","name":"anyname","description":"anydescription"}

Here is the PHP code on the Controller that should update the entity according to the JSON above (we are using JMS serializer Bundle):

$supplier = $serializer->deserialize(
    $this->get('request')->getContent(),
    'WhateverEntity',
    'json'
);

The EntityManger understands (correctly) that this is an update request (in fact, a SELECT query is implicitly triggered). The EntityManager also guess (not correctly) that CreatedAt property should be NULLified - it should instead keep the previous one.

How to fix this issue?

Answer 1

using the JMSSerializerBundle follow the install instructions at http://jmsyst.com/bundles/JMSSerializerBundle

either create your own serializer service or alter the JMSSerializerBundle to use the doctrine object constructor instead of the simple object constructor.

<service id="jms_serializer.object_constructor" alias="jms_serializer.doctrine_object_constructor" public="false"/>

This basically handles exactly what Ocramius solution does but using the JMSSerializerBundles deserialize.

Answer 2

It's possible as well to do it with Symfony Serializer using object_to_populate option.

Example: I receive JSON request. If record exists in database I want to update fields received in body, if it does not exist I want to create new one.

/**
 * @Route("/{id}", methods={"PUT"})
 */
public function upsert(string $id, Request $request, SerializerInterface $serializer)
{
  $content = $request->getContent(); // Get json from request

  $product = $this->getDoctrine()->getRepository(Product::class)->findOne($id); // Try to find product in database with provided id

  if (!$product) { // If product does not exist, create fresh entity
      $product = new Product();
  }

  $product = $serializer->deserialize(
            $content,
            Product::class,
            'json',
            ['object_to_populate' => $product] // Populate deserialized JSON content into existing/new entity
        );
  // validation, etc...
  $this->getDoctrine()->getManager()->persist($product); // Will produce update/instert statement 
  $this->getDoctrine()->getManager()->flush($product);

// (...)