Migration to Version 3.0

Upgrading laminas-serializer will require some code changes, depending on how the serializers were used.

Breaking Changes

Static Methods in Serializer Implementation

The biggest breaking change in v3 relates to the Laminas\Serializer\Serializer. This class has been removed due to its potential side-effects and for not following the S within SOLID.

This class was:

• a registry (by providing a method to both persist and provide a "default" serializer instance)
• a factory (by providing methods to create objects based on arguments passed to methods)
• a serializer (by providing serialize and unserialize which then called magically an AdapterInterface implementation)

To enable projects and 3rd-party libraries to provide their own serializer implementations (which are also available via the AdapterPluginManager), this class was removed in favor of dependency injection.

The amount of work to migrate projects consuming the Laminas\Serializer\Serializer class depends on the way how it was used in projects.

Projects Making Use of Serializer#setDefaultAdapter

In case you are using this method within a laminas-mvc or mezzio project, laminas got your back. You can now configure the projects default adapter by using the dependency configuration. If your project uses Serializer#setDefaultAdapter outside of laminas-mvc or mezzio projects, you have to provide your own registry. You can either copy the current implementation into your project or implement an own minimal implementation such as:

namespace MyNamespace;

use Laminas\Serializer\Adapter\AdapterInterface;use Laminas\Serializer\Adapter\PhpSerialize;

final class SerializerRegistry
{
     private static null|AdapterInterface $adapter = null;
     
     public static function getDefaultAdapter(): AdapterInterface
     {
        if (self::$adapter) {
            return self::$adapter;
        }
        
        return self::$adapter = new PhpSerialize();
     }
     
     public static function setDefaultAdapter(AdapterInterface $adapter): void
     {
        self::$adapter = $adapter;
     }
}

It is highly recommended to use dependency injection over a registry.

Projects Making Use of Serializer#getDefaultAdapter

In case you are using this method within a laminas-mvc or mezzio project, laminas got your back. You can now retrieve the projects default adapter by using the container: $container->get(\Laminas\Serializer\Adapter\AdapterInterface::class);. This will always provide an instance of AdapterInterface (PhpSerialize by-default unless configured otherwise) and therefore provides the same value as Serializer#getDefaultAdapter.

Outside of laminas frameworks, the changes are depending on how the project is interacting with the Serializer class. If your project does not call Serializer#setDefaultAdapter, code can be replaced with new \Laminas\Serializer\Adapter\PhpSerialize(). If you think that is not a good solution, feel free to implement your own registry. Refer to the section above on how to do so.

Projects Making Use of Serializer#serialize or Serializer#unserialize

There are no replacements for these methods. You can either instantiate PhpSerialize adapter (which is the default) or, in case your projects uses Serializer#setDefaultAdapter, please refer to the section above.

Projects Making Use of Serializer#factory

This method has multiple ways to get called:

Passing an Instance of AdapterInterface

use Laminas\Serializer\Adapter\PhpSerialize;

$adapter = new PhpSerialize();
$adapter = Serializer::factory($adapter); // unnecessary method call
$adapter = Serializer::factory($adapter, ['unserialize_class_whitelist' => false]); // unnecessary method call

In both cases, the $adapter was already an instance of an adapter prior calling the factory method. The factory method always immediately returned the $adapter in case it was not a string and therefore, the method calls can be simply removed.

Passing an Already Known class-string

use Laminas\Serializer\Adapter\PhpSerialize;

$adapterClassName = PhpSerialize::class;
$adapter = Serializer::factory($adapterClassName);
$adapter = Serializer::factory($adapterClassName, ['unserialize_class_whitelist' => false]);

In this example, we obviously are aware that we want a PhpSerialize serializer. Please directly instantiate the serializer instead of calling the factory method.

Passing a Service Alias

$adapterAlias = 'phpserialize';
$adapter = Serializer::factory($adapterAlias);
$adapter = Serializer::factory($adapterAlias, ['unserialize_class_whitelist' => false]);

Same as the example where we pass class-string. Please refactor your code to directly instantiate the serializer instead.

Passing an Unknown Value

use Laminas\Serializer\Adapter\AdapterInterface;

function myfunction(string|AdapterInterface $adapterAliasOrClassStringOrInstance, ?array $adapterOptions = null): string
{
    $adapter = Serializer::factory($adapterAliasOrClassStringOrInstance, $adapterOptions);
    
    return $adapter->serialize(new stdClass());
}

This will require you to use the Laminas\Serializer\AdapterPluginManager.

use Laminas\Serializer\Adapter\AdapterInterface;
use Laminas\Serializer\AdapterPluginManager;

function myfunction(string|AdapterInterface $adapterAliasOrClassStringOrInstance, ?array $adapterOptions = null): string
{
    $adapter = $adapterAliasOrClassStringOrInstance;
    if (!$adapter instanceof AdapterInterface) {
        $plugins = new AdapterPluginManager();
        $adapter = $plugins->build($adapterAliasOrClassStringOrInstance, $adapterOptions);
    }
    
    return $adapter->serialize(new stdClass());
}

Niche Serializer Implementations

With v3, some of the more niche serializer implementations were removed.

• MsgPack
• PythonPickle
• Wddx

All of these serializers were already deprecated in v2.15.0. For a more detailed reasoning on why these were removed please refer to the RFC. In case your project is still depending on these implementations, feel free to copy the adapter source from latest 2.x and adapt the required type-additions to comply with v3.0+.

Checklist

1. laminas-serializer is updated to the latest version from within 2.x
2. Search your code for the usage of Laminas\Serializer\Serializer, if this class is in-use, please refer to its dedicated migration section
3. If your project provides an implementation of AdapterInterface or AbstractAdapter, please migrate your code to comply with the latest type-additions
4. Check if your project is using one of the niche serializer implementations which were removed with this release