A swift package for adding decoding functionality to URLSession. It is a very small but handful library, that solves the common pattern of deserialization of a response, and fallback on another message format in case of an HTTP error.
We have been using it in some form over the years at former Viacom, now Paramount. Since Swift Package Manager support in Xcode 11.0, we use it on production in several projects.
Add to your Package.swift:
dependencies: [
.package(url: "https://github.com/ViacomInc/URLSessionDecodable.git", .upToNextMajor(from: "0.1.0"))
]
Example usage, fetching a response that has a specific error format if error is handled by a backend:
struct AnimalsResponse: Decodable {
let name: String
}
struct AnimalsError: Error {
// optional, there are also other errors than the ones handled by a backend
let errorResponse: ErrorResponse?
}
struct ErrorResponse: Decodable {
let userMessage: String
}
func getFavoriteAnimals(urlSession: URLSession = .shared,
completionHandler: (Result<AnimalsResponse, AnimalsError>) -> Void) -> Cancelable {
let url = URL(string: "https://myservice.com/favoriteAnimals")!
return urlSession.decodableTask(with: url,
method: .get,
parameters: nil,
headers: nil,
decoder: JSONDecoder()) { result in
switch result {
case .success(let animals):
completionHandler(.success(animals))
case .failure(let error):
let animalsFetchError: ErrorResponse? = error.decodeResponse(using: JSONDecoder())
completionHandler(.failure(AnimalsError(errorResponse: animalsFetchError)))
}
}
}
Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.
URLSessionDecodable is released under the Apache 2.0 license. See LICENSE for details.