Hands-On Design Patterns with Swift

Parsing responses with Decodable

A Decodable object is an object that can be transformed from Data to a pure Swift object or struct, through Decoder. This section will not provide a full coverage of codables, but rather, a quick example that shows how you can leverage this when communicating with a server in a generic way.

Let's re-work the previous example a bit and improve the code; instead of returning data, we want to return a pure Swift object:

func get<T>(url: URL, callback: @escaping (T?, Error?) -> Void) -> URLSessionTask where T: Decodable {    let task = URLSession.shared.dataTask(with: url) { data, response, error in        if let error = error {            callback(nil, error)            return        }        // Very simple handling of errors, you may wanna  // have a more ...