CustomizingNetworkingBackend.md

Customizing Networking Backend

APIKit uses NSURLSession as networking backend by default. Since Session has abstraction layer of backend called SessionAdapterType, you can change the backend of Session like below:

• Third party HTTP client like Alamofire
• Mock backend like TestSessionAdapter
• NSURLSession with custom configuration and delegate

Demo implementation of Alamofire adapter is available here.

SessionAdapterType

SessionAdapterType provides an interface to get (NSData?, NSURLResponse?, NSError?) from NSURLRequest and returns SessionTaskType for cancellation.

public protocol SessionAdapterType {
    func resumedTaskWithURLRequest(URLRequest: NSURLRequest, handler: (NSData?, NSURLResponse?, NSError?) -> Void) -> SessionTaskType
    func getTasksWithHandler(handler: [SessionTaskType] -> Void)
}

public protocol SessionTaskType: class {
    func cancel()
}

How Session works with SessionAdapterType

Session takes an instance of type that conforms SessionAdapterType as a parameter of initializer.

public class Session {
    public let adapter: SessionAdapterType

    public init(adapter: SessionAdapterType) {
        self.adapter = adapter
    }

    ...
}

Once it is initialized with a session adapter, it sends NSURLRequest and receives (NSData?, NSURLResponse?, NSError?) via the interfaces which are defined in SessionAdapterType.

func sendRequest<T: RequestType>(request: T, handler: (Result<T.Response, APIError>) -> Void = {r in}) -> SessionTaskType? {
    let URLRequest: NSURLRequest = ...
    let task = adapter.resumedTaskWithURLRequest(URLRequest) { data, URLResponse, error in
        ...
    }
}