Vapor API client for auth-template: Create User - part 2

.swift

import Combine

// With Combine we return a DataTaskPublisher instead of using the completion handler of the DataTask
func postUser(user: User) throws -> URLSession.DataTaskPublisher {
    let headers = [
        "Content-Type": "application/json",
        "cache-control": "no-cache",
    ]
    let encoder = JSONEncoder()
    guard let postData = try? encoder.encode(user) else {
        throw APIError.invalidBody
    }
    guard let url = URL(string: baseURL + "/users" ) else {
        throw APIError.invalidEndpoint
    }
    var request = URLRequest(url: url,
                             cachePolicy: .useProtocolCachePolicy,
                             timeoutInterval: 10.0)
    request.httpMethod = "POST"
    request.allHTTPHeaderFields = headers
    request.httpBody = postData as Data
    
    let session = URLSession.shared
    return session.dataTaskPublisher(for: request)
}

// Basic usage of the API client with dataTaskPublisher

// Create a DataTaskPublisher
let postUserPublisher = try? postUser(user: User(id:3))

// Use the sink Subscriber to complete the Publisher -> Subscriber pipeline
let cancellable = postUserPublisher?.sink(receiveCompletion: { (completion) in
    switch completion {
    case .failure(let error):
        print(error)
    case .finished:
        print("DONE - postUserPublisher")
    }
}, receiveValue: { (data, response) in
    if let string = String(data: data, encoding: .utf8) {
        print(string)
    }
})