@@ -238,14 +238,107 @@ When serializing, you can set a callback to format a specific object property::
238238 $serializer->serialize($person, 'json');
239239 // Output: {"name":"cordoval", "age": 34, "createdAt": "2014-03-22T09:43:12-0500"}
240240
241+ Handling Circular References
242+ ----------------------------
243+
244+ ..versionadded ::2.6
245+ Handling of circular references was introduced in Symfony 2.6. In previous versions of Symfony, circular references
246+ lead to infinite loops.
247+
248+ Circular references are common when dealing with entities relations::
249+
250+ class Organization
251+ {
252+ private $name;
253+ private $members;
254+
255+ public function setName($name)
256+ {
257+ $this->name = $name;
258+ }
259+
260+ public function getName()
261+ {
262+ return $this->name;
263+ }
264+
265+ public function setMembers(array $members)
266+ {
267+ $this->members = $members;
268+ }
269+
270+ public function getMembers()
271+ {
272+ return $this->members;
273+ }
274+ }
275+
276+ class Member
277+ {
278+ private $name;
279+ private $organization;
280+
281+ public function setName($name)
282+ {
283+ $this->name = $name;
284+ }
285+
286+ public function getName()
287+ {
288+ return $this->name;
289+ }
290+
291+ public function setOrganization(Organization $organization)
292+ {
293+ $this->organization = $organization;
294+ }
295+
296+ public function getOrganization()
297+ {
298+ return $this->organization;
299+ }
300+ }
301+
302+ To avoid infinite loops,:class: `Symfony\\ Component\\ Serializer\\ Normalizer\\ GetSetMethodNormalizer ` throws a
303+ :class: `Symfony\\ Component\\ Serializer\\ Exception\\ CircularReferenceException ` when such case is encountered::
304+
305+ $member = new Member();
306+ $member->setName('Kévin');
307+
308+ $org = new Organization();
309+ $org->setName('Les-Tilleuls.coop');
310+ $org->setMembers(array($member));
311+
312+ $member->setOrganization($kevin);
313+
314+ echo $serializer->serialize($org, 'json'); // Throws a CircularReferenceException
315+
316+
317+ The `setCircularReferenceLimit() ` method of this normalizer sets the number of times serializing the same object must
318+ occur before considering being in a circular reference. Its default value is `1 `.
319+
320+ Instead of throwing an exception, circular references can also be handled by custom callables. This is especially useful
321+ when serializing entities having unique identifiers::
322+
323+ $encoder = new JsonEncoder();
324+ $normalizer = new GetSetMethodNormalizer();
325+
326+ $normalizer->setCircularReferenceHandler(function ($object) {
327+ return $object->getName();
328+ });
329+
330+ $serializer = new Serializer(array($normalizer), array($encoder));
331+ echo $serializer->serialize($org, 'json');
332+ // {"name":"Les-Tilleuls.coop","members":[{"name":"K\u00e9vin", organization: "Les-Tilleuls.coop"]}
333+
241334JMSSerializer
242335-------------
243336
244337A popular third-party library, `JMS serializer `_, provides a more
245338sophisticated albeit more complex solution. This library includes the
246339ability to configure how your objects should be serialized/deserialized via
247340annotations (as well as YAML, XML and PHP), integration with the Doctrine ORM,
248- and handling of other complex cases (e.g. circular references) .
341+ and handling of other complex cases.
249342
250343.. _`JMS serializer` :https://github.com/schmittjoh/serializer
251344.. _Packagist :https://packagist.org/packages/symfony/serializer