7-custom-deserializers.md

title	weight
Custom deserializers	7

To create a custom deserializer, you need to create a class that implements the \Junges\Kafka\Contracts\MessageDeserializer contract. This interface force you to declare the deserialize method.

To set the deserializer you want to use, use the usingDeserializer method:

$consumer = \Junges\Kafka\Facades\Kafka::consumer()->usingDeserializer(new MyCustomDeserializer());

NOTE: The deserializer class must use the same algorithm as the serializer used to produce this message.

Using AVRO deserializer

To use the AVRO deserializer on your consumer, add the Avro deserializer:

use FlixTech\AvroSerializer\Objects\RecordSerializer;
use FlixTech\SchemaRegistryApi\Registry\CachedRegistry;
use FlixTech\SchemaRegistryApi\Registry\BlockingRegistry;
use FlixTech\SchemaRegistryApi\Registry\PromisingRegistry;
use FlixTech\SchemaRegistryApi\Registry\Cache\AvroObjectCacheAdapter;
use GuzzleHttp\Client;


$cachedRegistry = new CachedRegistry(
    new BlockingRegistry(
        new PromisingRegistry(
            new Client(['base_uri' => 'kafka-schema-registry:9081'])
        )
    ),
    new AvroObjectCacheAdapter()
);

$registry = new \Junges\Kafka\Message\Registry\AvroSchemaRegistry($cachedRegistry);
$recordSerializer = new RecordSerializer($cachedRegistry);

//if no version is defined, latest version will be used
//if no schema definition is defined, the appropriate version will be fetched form the registry
$registry->addBodySchemaMappingForTopic(
    'test-topic',
    new \Junges\Kafka\Message\KafkaAvroSchema('bodySchema' , 9 /* , AvroSchema $definition */)
);
$registry->addKeySchemaMappingForTopic(
    'test-topic',
    new \Junges\Kafka\Message\KafkaAvroSchema('keySchema' , 9 /* , AvroSchema $definition */)
);

// if you are only decoding key or value, you can pass that mode as additional third argument
// per default both key and body will get decoded
$deserializer = new \Junges\Kafka\Message\Deserializers\AvroDeserializer($registry, $recordSerializer /*, AvroDecoderInterface::DECODE_BODY */);

$consumer = \Junges\Kafka\Facades\Kafka::consumer()->usingDeserializer($deserializer);