APIClient.playground

//: Playground - noun: a place where people can play

// From That Thing in Swift
// https://thatthinginswift.com

import UIKit
import XCPlayground

XCPlaygroundPage.currentPage.needsIndefiniteExecution = true

class ClientAPI {
    
    func login(email: String, password: String, completion: (success: Bool, message: String?) -> ()) {
        let loginObject = ["email": email, "password": password]

        post(clientURLRequest("auth/local", params: loginObject)) { (success, object) -> () in

            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                if success {
                    completion(success: true, message: nil)
                } else {
                    var message = "there was an error"
                    if let object = object, let passedMessage = object["message"] as? String {
                        message = passedMessage
                    }
                    completion(success: true, message: message)
                }
            })
        }
    }

    // MARK: private composition methods

    private func post(request: NSMutableURLRequest, completion: (success: Bool, object: AnyObject?) -> ()) {
        dataTask(request, method: "POST", completion: completion)
    }

    private func put(request: NSMutableURLRequest, completion: (success: Bool, object: AnyObject?) -> ()) {
        dataTask(request, method: "PUT", completion: completion)
    }

    private func get(request: NSMutableURLRequest, completion: (success: Bool, object: AnyObject?) -> ()) {
        dataTask(request, method: "GET", completion: completion)
    }

    private func dataTask(request: NSMutableURLRequest, method: String, completion: (success: Bool, object: AnyObject?) -> ()) {
        request.HTTPMethod = method

        let session = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration())

        session.dataTaskWithRequest(request) { (data, response, error) -> Void in
            if let data = data {
                let json = try? NSJSONSerialization.JSONObjectWithData(data, options: [])
                if let response = response as? NSHTTPURLResponse where 200...299 ~= response.statusCode {
                    completion(success: true, object: json)
                } else {
                    completion(success: false, object: json)
                }
            }
        }.resume()
    }

    private func clientURLRequest(path: String, params: Dictionary<String, AnyObject>? = nil) -> NSMutableURLRequest {
        let request = NSMutableURLRequest(URL: NSURL(string: "http://api.example.com/"+path)!)
        if let params = params {
            var paramString = ""
            for (key, value) in params {
                let escapedKey = key.stringByAddingPercentEncodingWithAllowedCharacters(.URLQueryAllowedCharacterSet())
                let escapedValue = value.stringByAddingPercentEncodingWithAllowedCharacters(.URLQueryAllowedCharacterSet())
                paramString += "\(escapedKey)=\(escapedValue)&"
            }

            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
            request.HTTPBody = paramString.dataUsingEncoding(NSUTF8StringEncoding)
        }

        return request
    }
}

let client = ClientAPI()
client.login("[email protected]", password: "password") { (success, message) -> () in
    if success {
        print("logged in successfully!")
    } else {
        print("there was an error:", message)
    }

    XCPlaygroundPage.currentPage.finishExecution()
}