ruby-on-rails - Rails JSON 到 Swift 2 JSON

Question

我正在尝试使用 JSON 将数据从 Rails Web 服务器共享到 swift 应用程序。我正在努力建立这种联系。

从 Rails Controller :

    ...
    output = x.to_json
    render :json => output 
    ...

在 Swift iOS 应用程序中:

import UIKit
class FirstViewController: UIViewController {
override func viewDidLoad() {
    super.viewDidLoad()
    reachForWebsite()
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}
func reachForWebsite(){
    let url = NSURL(string: "myURL")
    let request = NSURLRequest(URL: url!)
    let task = NSURLSession.sharedSession().dataTaskWithURL(url!) {(data, response, error) in
        println(NSString(data: data!, encoding: NSUTF8StringEncoding))
        var error: NSError? = nil
        if let jsonObject = NSJSONSerialization.JSONObjectWithData(data!, options: nil, error = &error){
            if let dict = jsonObject as? NSDictionary {
                println(dict)
            } else {
                println("not a dictionary")
            }
        } else {
            println("Could not parse JSON: \(error!)")
        }
            println(data.dynamicType)
        }
    }
    task!.resume()
}
}

我可以验证我是否成功接收数据，因为我可以将其转换为字符串并将其打印到应用程序上的控制台。但是我无法从中创建 NSDictionary 对象。错误随着每个修补程序的不同而变化，但与Options和try catch相关。

JSON

{"inside":[{"name":"BOB"}, ...],"outside":[{"name":"TIM","type":"HUMAN","id":1}, ...],"info":{"time":"2015-07-02"}}

Answer 1

为什么不尝试用 Swift 2 解析 JSON

guard let task = NSURLSession.sharedSession().dataTaskWithURL(URL) {(data, response, error) in
guard let data = data, error == nil 
else 
{
    // Checks for errors if the task fails like for bad connectivity.
    print(error);
    return;
}
do 
{
    guard let JSONDict = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [NSObject: AnyObject] 
    else
    {
        // The JSONDict wasn't a dictionary. Maybe its an array here? If it is change the structure of the parsing.
        print("The JSON wasn't a dictionary. Try array by optional casting to [AnyObject] instead of the cast above to [NSObject: AnyObject]")
        return
    }
    print("Parsed JSON successfully as dictionary: \(JSONDict)")
    // Do stuff with the JSONDict which is a Swift dictionary.
    // For example: let some = JSONDict["key"] as? ValueType will allow you to access the key of the JSONDict
}
catch 
{ 
    // JSON parsing error. 
    print(error) 
}
else 
{ 
     // Error task wasn't created that's unusual unless the URL was bad.
     // Fail here so that you can trace the stack and debug.
     assertionFailure();
}
task.resume()

如果它不起作用，请告诉我哪里失败以及控制台会打印什么内容。