json_encode on class with magic properties

Question

I am trying to json_encode an array of objects who all have magic properties using __get and __set. json_encode completely ignores these, resulting in an array of empty objects (all the normal properties are private or protected).

So, imagine this class:

class Foo
{
    public function __get($sProperty)
    {
        if ($sProperty == 'foo')
        {
            return 'bar!';
        }
        return null;
    }
}

$object = new Foo();
echo $object->foo; // echoes "foo"
echo $object->bar; // warning
echo json_encode($object); // "{}"

I've tried implementing IteratorAggregate and Serializable for the class, but json_encode still doesn't see my magic properties. Since I am trying to encode an array of these objects, an AsJSON()-method on the class won't work either.

Update! It seems the question is easy to misunderstand. How can I tell json_encode which "magic properties" exist? IteratorAggregate didn't work.

BTW: The term from the PHP documentation is "dynamic entities". Whether or not the magic properties actually exist is arguing about semantics.

Answer 1

PHP 5.4 has an interface called JsonSerializable. It has one method, jsonSerialize which will return the data to be encoded. This problem would be easily fixed by implementing it.