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Encoders basically turn arrays into formats and vice versa. They implement Symfony\Component\Serializer\Encoder\EncoderInterface for encoding (array to format) and Symfony\Component\Serializer\Encoder\DecoderInterface for decoding (format to array).

You can add new encoders to a Serializer instance by using its second constructor argument:

use Symfony\Component\Serializer\Serializer;
use Symfony\Component\Serializer\Encoder\XmlEncoder;
use Symfony\Component\Serializer\Encoder\JsonEncoder;

$encoders = array(new XmlEncoder(), new JsonEncoder());
$serializer = new Serializer(array(), $encoders);

Built-in Encoders

Two encoders are used in the example above:

  • Symfony\Component\Serializer\Encoder\XmlEncoder to encode/decode XML
  • Symfony\Component\Serializer\Encoder\JsonEncoder to encode/decode JSON

The XmlEncoder

This encoder transforms arrays into XML and vice versa.

For example, take an object normalized as following:

array('foo' => array(1, 2), 'bar' => true);

The XmlEncoder will encode this object like that:

<?xml version="1.0"?>

Be aware that this encoder will consider keys beginning with @ as attributes:

$encoder = new XmlEncoder();
$encoder->encode(array('foo' => array('@bar' => 'value')));
// will return:
// <?xml version="1.0"?>
// <response>
//     <foo bar="value" />
// </response>

The JsonEncoder

The JsonEncoder is much simpler and is based on the PHP json_encode and json_decode functions.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.