Faactory.RestClient 0.3.0-preview-2

REST Client for .NET

This projects contains the implementation for a REST Client for .NET. It's built on top of the original HttpClient and fully supports IHttpClientFactory for dependency injection.

Getting started

Install the package.

$ dotnet add package Faactory.RestClient

To create a client instance using dependency injection

IServiceCollection services = new ServiceCollection()
    ...
    .AddRestClient( "jsonplaceholder", "https://jsonplaceholder.typicode.com" )
    ...

This will give you access to an IRestClientFactory interface. Then, wherever you need a client

public class MyClass
{
    private readonly IRestClient client;

    public MyClass( IRestClientFactory clientFactory )
    {
        client = clientFactory.CreateClient( "jsonplaceholder" );
    }
    ...
}

If creating the client manually, an HttpClient instance needs to be passed through

var httpClient = ...
var restClient = new RestClient( httpClient, "https://jsonplaceholder.typicode.com" );

Using

All request operations respond with a RestResponse or RestObjectResponse, containing the status code of the operation and the content, if any.

var response = await restClient.GetAsync( "todos/1" );

if ( response.IsOk() )
{
    // do something with the content only if response is a 200 OK
}

Configuring

It is possible to customize a request's configuration, such as headers or query parameters. We do that by invoking Configure and a configuration method, which returns an IRestRequest instance.

IRestRequest request = restClient.Configure( options =>
{
    options.QueryParameters.Add( "address.city", "Bartholomebury" );
} );

var response = request.GetAsync( "users" );

// or directly with a fluent syntax

var response = await restClient.Configure( options =>
{
    options.QueryParameters.Add( "address.city", "Bartholomebury" );
})
.GetAsync( "users" );

It's worth noting that IRestRequest instances are reusable and multiple operations can be performed with the same instance. Here's an example

var request = restClient.Configure( options =>
{
    options.Headers.Add( "X-Custom-Header", "custom header value" );
} );

var ids = new int[] { 1, 2, 3 };

var getTasks = ids.Select( id => request.GetAsync( $"users/{id}" ) )
    .ToArray();

var responses = await Task.WhenAll( getTasks );

Working with JSON

The client includes extensions to serialize and deserialize JSON content. This can be done by manually deserializing a RestResponse instance

var response = await restClient.GetAsync( "todos/1" );

var todo = response.Deserialize<Todo>();

Or directly with the request extension, which returns the deserialized instance instead; be aware that this method will only deserialize the content if the response's status code is a 200 (Ok), otherwise it will return default<T>. Something else to consider is that this method doesn't give us access to the response's status code and headers.

var todo = await restClient.GetJsonAsync<Todo>( "todos/1" );

For the other request operations, the serialization process is applied the other way around and the response is always a RestResponse. For example, a POST request

Todo todo = ...;

var response = await restClient.PostJsonAsync( "todos", todo );

Polymorphic JSON Serialization

By default, the client uses Microsoft's JSON serializer, therefore, there is limited support for polymorphic serialization and deserialization is not supported at all. You can find more information in this article where you will also find a few workarounds, including writing a custom converter.

If you rather use Newtonsoft's Json.NET (or any other), you can easilly write a custom serializer. Here's an example for Newtonsoft's

public class NewtonsoftJsonSerializer : ISerializer
{
    public byte[] SerializeObject<T>( T value )
    {
        var json = JsonConvert.SerializeObject( value );

        return Encoding.UTF8.GetBytes( json );
    }
    
    public T DeserializeObject<T>( byte[] content )
    {
        var json = Encoding.UTF8.GetString( content );

        return JsonConvert.DeserializeObject<T>( json );
    }
}

If you are using dependency injection, you can add the serializer by injecting it into the container services.

IServiceCollection services = new ServiceCollection()
...
services.AddRestClient( "jsonplaceholder", "https://jsonplaceholder.typicode.com" )

// add our custom serializer
services.AddSingleton<IJsonSerializer, NewtonsoftJsonSerializer>();

If you are not using dependency injection, just pass it into the constructor.

var httpClient = ...
var restClient = new RestClient( 
    httpClient,
    "https://jsonplaceholder.typicode.com",
    new NewtonsoftJsonSerializer() );

You can also pass a custom serializer if deserializing from a RestResponse instance

var customSerializer = new NewtonsoftJsonSerializer();

var response = await restClient.GetAsync( "todos/1" );

var todo = response.Deserialize<Todo>( customSerializer );

Authorization header

You can use extension methods to configure the Authorization header. Currently, the supported schemes are

• Basic authentication
• Bearer token

This can be applied to the entire client, when configuring the underlying HttpClient instance with dependency injection

IServiceCollection services = new ServiceCollection()
    ...
    .AddRestClient( "jsonplaceholder", "https://jsonplaceholder.typicode.com", httpClient =>
    {
        httpClient.AddBasicAuthentication( "username", "password" );
    } )
    ...

when manually creating the client instance, by accessing the underlying client extensions

var httpClient = ...

httpClient.AddBasicAuthentication( "username", "password" );

var restClient = new RestClient( httpClient, "https://jsonplaceholder.typicode.com" );

// accessing the underlying client instance works the same
// restClient.HttpClient.AddBasicAuthentication( "username", "password" );

or when customizing/scoping a request

var response = await restClient.Configure( "users", options =>
{
    options.AddBasicAuthentication( "username", "password" );
})
.GetAsync();

Note: These extensions require adding the namespace Faactory.RestClient

EXPERIMENTAL: REST-Schema Extensions

If you are working with an API that is compatible with REST-Schema, there are a few extensions that you can use. These are experimental features, so they might change in the future, disappear or not function properly.

We can send a map schema spec through the headers by customizing a request with the available extensions.

var response = await restClient.Configure( "users", options =>
{
    options.SchemaMap( new {
        spec = new {
            _ = new string[] { "id", "name", "email", "address" },
            address = new string[] { "street", "city", "zipcode" }
        }
    } );
})
.GetAsync();

Similarly we can send an include schema spec.

var response = await restClient.Configure( "users", options =>
{
    options.SchemaInclude( new {
        spec = new {
            _ = new string[] { "address" }
        }
    } );
})
.GetAsync();