Online PHP editor | refs for DBFJT

<?php class Foo implements JsonSerializable { private $foo = 1; private $serializer; public function setSerializer(Closure $serializer) { $this->serializer = $serializer; } public function jsonSerialize() { if (method_exists($this->serializer, 'call')) { return $this->serializer->call($this); } return call_user_func($this->serializer->bindTo($this, $this)); } } class Serializer { public function formatThisWay() { return function() { return $this->foo * 10; }; } public function formatThatWay() { return function() { return ['foo' => $this->foo * 10]; }; } } $foo = new Foo; $serializer = new Serializer; $foo->setSerializer($serializer->formatThisWay()); echo json_encode($foo); $foo->setSerializer($serializer->formatThatWay()); echo json_encode($foo);