MyRESTClient.swift

import Foundation
import Alamofire

struct MyRESTClient {

    let url: NSURL // this, being in a struct, will become a parameter of the initializer automatically

    func getAvailableItems(completion: ((items: [MyItem]?) -> ())) {
        Alamofire.request(.GET, url.absoluteString + "/items", parameters: nil)
            .validate(statusCode: 200..<300)
            .validate(contentType: ["application/json"])
            .responseJSON { response in
                if let JSON = response.result.value as? [String : AnyObject],
                    items = JSON["items"] as? [String] {
                        var returnArray = [MyItem]()
                        for item in items {
                            returnArray.append(MyItem(name: item))
                        }
                        completion(items: returnArray)
                } else {
                    completion(items: nil)
                }
        }
    }

}