NetworkingX

Introduction

NetworkingX is a clean, lightweight framework for making HTTP requests built over the URLSession of swift language. The main objective of this framework is to separate the networking protocols in smaller steps, giving us extra flexibility in code management.

Requirements

• iOS 10.0+ / macOS 10.12+ / tvOS 10.0+ / watchOS 3.0+
• Xcode 11+
• Swift 5.1+

Installation

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. To install NetworkingX, simply add the following line to your Podfile:

pod 'NetworkingX'

Swift Package Manager

The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler. NetworkingX also support its use on supported platforms.

Once you have your Swift package set up, adding NetworkingX as a dependency is as easy as adding it to the dependencies value of your Package.swift.

dependencies: [
    .package(url: "https://github.com/prashantLalShrestha/NetworkingX.git", .upToNextMajor(from: "1.3.0"))
]

Usage

NetworkingX is quite simple to use. However there are some of the protocols and classes to take notes of.

NetworkConfigurable

It is a protocol implemented to configure the base HTTP network configurations. This includes the base url of the hosted address, common headers and common query parameters.

public protocol NetworkConfigurable {
    var baseURL: URL { get }
    var headers: [String: String] { get }
    var queryParameters: [String: String] { get }
}

We can create an object from it's default implementation ApiDataNetworkConfig.

let config = ApiDataNetworkConfig(baseURL: URL(string: "https://url.to.api/"))

NetworkService

A service protocols used to make HTTP requests. It's default implementation DefaultNetworkService wraps the URLSession().dataTask function. You can use this protocol to create your own implementation, for example, using Alamofire.

public protocol NetworkService {
    typealias CompletionHandler = (Result<Data?, NetworkError>) -> Void
    
    func request(endpoint: Requestable, completion: @escaping CompletionHandler) -> NetworkCallable?
}

The above made network config object is used in NetworkService. We can create a NetworkService object as:

let networkService = DefaultNetworkService(config: config)

NetworkSessionManager

NetworkSessionManager works as an interceptor in between HTTP requests. We can use this protocol to maintain the access tokens, authentications.

public protocol NetworkSessionManager {
    var acceptableStatusCodes: [Int] { get }
    typealias CompletionHandler = (Data?, URLResponse?, Error?) -> Void
    
    func request(_ request: URLRequest,
                 completion: @escaping CompletionHandler) -> NetworkCallable
}

Typically, we use NetworkSessionManager in our NetworkService class.

let networkService = DefaultNetworkService(config: config, sessionManager: DefaultNetworkSessionManager())

Endpoint

We create an endpoint for each network api calls. Endpoint implements the protocol Requestable

public protocol Requestable {
    var path: String { get }
    var isFullPath: Bool { get }
    var method: HTTPMethodType { get }
    var headerParamaters: [String: String] { get }
    var queryParametersEncodable: Encodable? { get }
    var queryParameters: [String: Any] { get }
    var bodyParamatersEncodable: Encodable? { get }
    var bodyParamaters: [String: Any] { get }
    var bodyEncoding: ParameterEncoding { get }

    func urlRequest(with networkConfig: NetworkConfigurable) throws -> URLRequest
}

As you can see in the above protocol, we will be defining our api call configurations in here.

struct Endpoints {
    static func authenticateUser(request: UserAuthenticationRequest) -> Endpoint<UserAuthenticationResponse> {
        return Endpoint(path: "path/of/login",
                        method: .post,
                        bodyParamatersEncodable: request,
                        bodyEncoding: URLEncoding.default
        )
    }
}

ParameterEncoding

A type used to define how a set of parameters are applied to a URLRequest. There are some inbuilt ParameterEncoding implementations in the framework.

• URLEncoding
• JSONEncoding
• XMLEncoding
• MultiPartEncoding

However, you can create your own Encoding implementation using this protocol and use it in your Endpoint.

DataTransferService

DataTransferService is a place where most of the work is done with the help of Endpoint, NetworkService and ErrorResolver.

public protocol DataTransferService {
    typealias CompletionHandler<T> = (Result<T, DataTransferError>) -> Void
    
    @discardableResult
    func request<T: Decodable, E: ResponseRequestable>(with endpoint: E,
                                                       completion: @escaping CompletionHandler<T>) -> NetworkCallable? where E.Response == T
                                                       
    @discardableResult
    func request<E: ResponseRequestable>(with endpoint: E,
                                         completion: @escaping CompletionHandler<Void>) -> NetworkCallable? where E.Response == Void
}

For simplicity, you can use the default implementation DefaultDataTransferService as:

let dataTransferService = DefaultDataTransferService(with: networkService)

DataTransferErrorResolver

It is used to resolve the NetworkError in the form of DataTransferError. We can create an implementation class for this protocol to map our errors.

public protocol DataTransferErrorResolver {
    func resolve(error: NetworkError) -> Error
}

And, use it in DefaultDataTransferService as:

let dataTransferService = DefaultDataTransferService(with: networkService,
                                                             errorResolver: DefaultDataTransferErrorResolver())

Now the sweet part,

After setting up our NetworkConfig, NetworkSessionManager, NetworkService, Endpoint, DataTransferService, we are now ready to make our network request,

let request = UserAuthenticationRequest(userName: "username", loginPassword: "password")

let endpoint = Endpoints.authenticateUser(request: request)
let task = dataTransferService.request(with: endpoint) { result in
    switch result {
    case .success(let response):
        // TODO: Update UI 
    case .failure(let error):
        // TODO: Handle Errors in UI
    }
}
task?.resume()

The main objective of this framework is to separate the networking protocols in smaller steps, giving us extra flexibility in code management expecially in, Clean Architecture.