Serialization

Serialization involves converting an object into a format that can be easily stored or transmitted. On the receiving end, the object is reconstructed back into its original form through deserialization. These two operations complement each other and can be important for dynamic, data-rich applications.

Uno.Extensions.Serialization allows for simplified access to serializer objects as dependencies. This library supports the new serialization technique powered by code generation.

Using a Serializer

The ISerializer interface provides a simple API for serializing and deserializing objects. Once serialization is enabled for an application, the ISerializer can be accessed as a dependency. The following example shows how to enable serialization for an application with the UseSerialization() extension method.

protected override void OnLaunched(LaunchActivatedEventArgs e)
{
    var appBuilder = this.CreateBuilder(args)
        .Configure(host => {
            host
            .UseSerialization()
        });
...

This extension method registers the ISerializer interface as a singleton service. The ISerializer interface can then be accessed as a dependency in any class that is registered with the host to serialize or deserialize objects.

public class MyViewModel : ObservableObject
{
    private ISerializer _serializer;

    public MyViewModel(ISerializer serializer)
    {
        this._serializer = serializer;
    }

    public void Serialize()
    {
        var myObject = new Person();
        var json = _serializer.Serialize(myObject);
    }
}

Configuring ISerializer

JSON

The default serializer implementation only supports serializing to JSON. Because it uses System.Text.Json, the specifics of this behavior can be configured with JsonSerializerOptions. The following example shows how to register an instance of JsonSerializerOptions with the host.

protected override void OnLaunched(LaunchActivatedEventArgs e)
{
    var appBuilder = this.CreateBuilder(args)
        .Configure(host => {
            host
            .UseSerialization(services =>
            {
                services
                    .AddSingleton(new JsonSerializerOptions { PropertyNameCaseInsensitive = true });
            });
        });
...

Source Generation

As of .NET 6, a code generation-enabled serializer is supported. The type to serialize is named Person in this example.

public record Person(string name, int age, double height, double weight);

To leverage the source generation feature for JSON serialization in an Uno.Extensions application, define a partial class which derives from a JsonSerializerContext, and specify which type is serializable with the JsonSerializable attribute:

using System.Text.Json.Serialization;

[JsonSerializable(typeof(Person))]
public partial class PersonJsonContext : JsonSerializerContext
{
}

This partial class can then be registered with the host using the AddJsonTypeInfo extension method:

protected override void OnLaunched(LaunchActivatedEventArgs e)
{
    var appBuilder = this.CreateBuilder(args)
        .Configure(host => {
            host
            .UseSerialization(services =>
            {
                services
                    .AddJsonTypeInfo(PersonJsonContext.Default.Person)
            });
        });
...

It follows that the PersonJsonContext will be automatically used by the injected ISerializer to serialize and deserialize instances of Person:

Person person = new("Megan", 23, 1.8, 90.0);

var json = _serializer.ToString<Person>(person);

Custom

The ISerializer interface can be implemented to support custom serialization to formats like XML or binary. This example shows how to register a custom ISerializer based type named XmlSerializerImpl with the host.