Serializers

The client has three serializers available. You will most likely never need to change the serializer, unless you have special requirements or are implementing a new protocol.

The job of the serializer is to encode the outgoing request body and decode the incoming response body. In 99% of cases, this is a simple conversion to/from JSON.

The default serializer is the SmartSerializer.

The SmartSerializer inspects the data to be encoded. If the request body is provided as a string, it is passed directly to Elasticsearch as a string. This allows users to provide raw JSON, or raw strings for certain endpoints that don’t have structure (such as the Analyze endpoint).

If the data is an array, it is converted to JSON. If the data provided was an empty array, the serializer manually converts the JSON from an empty array ([]) to an empty object ({}) so that it is valid JSON for Elasticsearch request bodies.

When decoding the response body, the SmartSerializer introspects the content_type headers to determine the appropriate encoding. If the data is encoded as JSON, it is decoded into an array using json_decode. Otherwise, it is returned as a string.

This functionality is required to cooperate with endpoints such as the Cat endpoints, which return tabular text instead of JSON.

The SmartSerializer is selected by default, but if you wish to manually configure it for explicitness, you can do so by using the setSerializer() method on the ClientBuilder object:

$client = ClientBuilder::create()
            ->setSerializer('\Elasticsearch\Serializers\SmartSerializer');
            ->build();

Note that the serializer is configured by specifying a namespace path to the serializer.

The ArrayToJSONSerializer inspects the data to be encoded. If the request body is provided as a string, it is passed directly to Elasticsearch as a string. This allows users to provide raw JSON, or raw strings for certain endpoints that don’t have structure (such as the Analyze endpoint).

If the data is an array, it is converted to json. If the data provided was an empty array, the serializer manually converts the JSON from an empty array ([]) to an empty object ({}) so that it is valid JSON for Elasticsearch request bodies.

When decoding the response body, everything is decoded to JSON from JSON. If the data is not valid JSON, null will be returned.

You can select ArrayToJSONSerializer by using the setSerializer() method on the ClientBuilder object:

$client = ClientBuilder::create()
            ->setSerializer('\Elasticsearch\Serializers\ArrayToJSONSerializer');
            ->build();

Note that the serializer is configured by specifying a namespace path to the serializer.

The EverythingToJSONSerializer tries to convert everything to JSON.

If the data provided was an empty array, the serializer manually converts the JSON from an empty array ([]) to an empty object ({}) so that it is valid JSON for Elasticsearch request bodies.

If the data was not an array and/or not convertible to JSON, the method returns null.

When decoding the response body, everything is decoded to JSON from JSON. If the data is not valid JSON, null is returned.

You can select EverythingToJSONSerializer by using the setSerializer() method on the ClientBuilder object:

$client = ClientBuilder::create()
            ->setSerializer('\Elasticsearch\Serializers\EverythingToJSONSerializer');
            ->build();

Note that the serializer is configured by specifying a namespace path to the serializer.

If you want to use your own custom serializer, you need to implement the SerializerInterface interface. Please keep in mind that the client uses a single Serializer object for all endpoints and all connections.

class MyCustomSerializer implements SerializerInterface
{

    /**
     * Serialize request body
     *
     * @param string|array $data Request body
     *
     * @return string
     */
    public function serialize($data)
    {
        // code here
    }

    /**
     * Deserialize response body
     *
     * @param string $data Response body
     * @param array  $headers Response Headers
     *
     * @return array|string
     */
    public function deserialize($data, $headers)
    {
        // code here
    }
}

​

To then use your custom serializer, you can specify the namespace path in the setSerializer() method of the ClientBuilder object:

$client = ClientBuilder::create()
            ->setSerializer('\MyProject\Serializers\MyCustomSerializer');
            ->build();

Alternatively, if your serializer has a constructor or further initialization that should occur before given to the client, you can instantiate an object and provide that instead:

$mySerializer = new MyCustomSerializer($a, $b, $c);
$mySerializer->setFoo("bar");

$client = ClientBuilder::create()
            ->setSerializer($mySerializer);
            ->build();

The majority of people will never need to change the default Serializer (SmartSerializer), but if you need to, it can be done via the setSerializer() method:

$serializer = '\Elasticsearch\Serializers\SmartSerializer';
$client = ClientBuilder::create()
            ->setSerializer($serializer)
            ->build();