Quick & dirty REST API calls with Swift. See http://grokswift.com/simple-rest-with-swift/

UISwiftRestDemo

// MARK: Using NSURLSession
  
// Get first todo item
let todoEndpoint: String = "http://jsonplaceholder.typicode.com/todos/1"
guard let url = NSURL(string: todoEndpoint) else {
  print("Error: cannot create URL")
  return
}
let urlRequest = NSURLRequest(URL: url)

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

let task = session.dataTaskWithRequest(urlRequest) {
  (data, response, error) in
  guard let responseData = data else {
    print("Error: did not receive data")
    return
  }
  guard error == nil else {
    print("error calling GET on /todos/1")
    print(error)
    return
  }
  // parse the result as JSON, since that's what the API provides
  do {
    guard let todo = try NSJSONSerialization.JSONObjectWithData(responseData, options: []) as? [String: AnyObject] else {
      // TODO: handle
      print("Couldn't convert received data to JSON dictionary")
      return
    }
    // now we have the todo, let's just print it to prove we can access it
    print("The todo is: " + todo.description)
    
    // the todo object is a dictionary
    // so we just access the title using the "title" key
    // so check for a title and print it if we have one
    guard let todoTitle = todo["title"] as? String else {
      print("Could not get todo title from JSON")
    }
    print("The title is: " + todoTitle)
  } catch  {
    print("error trying to convert data to JSON")
  }
}
task.resume()

// Create new todo
let todosEndpoint: String = "http://jsonplaceholder.typicode.com/todos"
guard let todosURL = NSURL(string: todosEndpoint) else {
  print("Error: cannot create URL")
  return
}
let todosUrlRequest = NSMutableURLRequest(URL: todosURL)
todosUrlRequest.HTTPMethod = "POST"
let newTodo: NSDictionary = ["title": "Frist todo", "body": "I iz fisrt", "userId": 1, "completed": 0]
let jsonTodo: NSData
do {
  jsonTodo = try NSJSONSerialization.dataWithJSONObject(newTodo, options: [])
  todosUrlRequest.HTTPBody = jsonTodo
} catch {
  print("Error: cannot create JSON from todo")
  return
}
todosUrlRequest.HTTPBody = jsonTodo

let session = NSURLSession()

let task = session.dataTaskWithRequest(todosUrlRequest) {
  (data, response, error) in
  guard let responseData = data else {
    print("Error: did not receive data")
    return
  }
  guard error == nil else {
    print("error calling POST on /todos/1")
    print(error)
    return
  }
  
  // parse the result as JSON, since that's what the API provides
  do {
    guard let receivedTodo = try NSJSONSerialization.JSONObjectWithData(responseData,
    options: []) as? [String: AnyObject] else {
      print("Could not get JSON from responseData as dictionary")
      return
    }
    print("The todo is: " + receivedTodo.description)
    
    guard let todoID = receivedTodo["id"] as? Int else {
      print("Could not get todoID as int from JSON")
      return
    }
    print("The ID is: \(todoID)")
  } catch  {
    print("error parsing response from POST on /todos")
    return
  }
}
task.resume()
  
// Delete first todo
let firstTodoEndpoint: String = "http://jsonplaceholder.typicode.com/todos/1"
let firstTodoUrlRequest = NSMutableURLRequest(URL: NSURL(string: firstTodoEndpoint)!)
firstTodoUrlRequest.HTTPMethod = "DELETE"

let session = NSURLSession()

let task = session.dataTaskWithRequest(firstTodoUrlRequest, completionHandler: {
  (data, response, error) in
  guard let _ = data else {
    print("error calling DELETE on /todos/1")
    return
  }
  print("DELETE ok")
})
task.resume()

// MARK: Using Alamofire

// Get first todo
let todoEndpoint: String = "http://jsonplaceholder.typicode.com/todos/1"
Alamofire.request(.GET, todoEndpoint)
  .responseJSON { response in
    guard response.result.error == nil else {
      // got an error in getting the data, need to handle it
      print("error calling GET on /todos/1")
      print(response.result.error!)
      return
    }
    
    guard let value = response.result.value else {
      print("no result data received when calling GET on /todos/1")
      return
    }
    // handle the results as JSON
    let todo = JSON(value)
    // now we have the results, let's just print them though a tableview would definitely be better UI:
    print("The todo is: " + todo.description)
    guard let title = todo["title"].string else {
      print("error parsing /todos/1")
      return
    }
    // to access a field:
    print("The title is: " + title)
}

// Create new todo
let todosEndpoint: String = "http://jsonplaceholder.typicode.com/todos"
let newTodo = ["title": "Frist Psot", "completed": 0, "userId": 1]
Alamofire.request(.POST, todosEndpoint, parameters: newTodo, encoding: .JSON)
  .responseJSON { response in
    guard response.result.error == nil else {
      // got an error in getting the data, need to handle it
      print("error calling POST on /todos/1")
      print(response.result.error!)
      return
    }
    
    guard let value = response.result.value else {
      print("no result data received when calling GET on /todos/1")
      return
    }
    let todo = JSON(value)
    print("The todo is: " + todo.description)
}

// Delete first todo
let firstTodoEndpoint: String = "http://jsonplaceholder.typicode.com/todos/1"
Alamofire.request(.DELETE, firstTodoEndpoint)
  .responseJSON { response in
    guard response.result.error == nil else {
      // got an error in getting the data, need to handle it
      print("error calling DELETE on /todos/1")
      print(response.result.error!)
      return
    }
    print("DELETE ok")
}