使用Alamofire和SwiftyJson从函数返回值 [英] Returning a value from a function with Alamofire and SwiftyJson

问题描述

我有一个返回信息菜单（基本上是菜单，menu_headers和项）的应用。我想要这样的东西：

I have an app that returns a menu of information (basically menus, menu_headers, and items). I'd like to have something like this:

EKMenu.getMenu(menu_id: Int)

这将返回一个菜单，但我想我需要在此处添加完成处理程序。

that would return a menu but I think I would need a completion handler in here.

我目前有：

class func getMenu(menu_id: Int){
//class func getMenu(menu_id: Int, completionHandler:(NSArray -> Void)){

  let url="https://www.example.com/arc/v1/api/menus/\(menu_id)/mobile"
  Alamofire.request(.GET, url).responseJSON() {
    (_, _, data, _) in
    println("within menu request")
    var json=JSON(data!)
    var menu=EKMenu()
    menu.name=json["menu"]["name"].stringValue
    for (key, subJson) in json["menu"]["menu_headers"]{
      EKMenu.processMenuHeaders(subJson)
    }
    // how would we return a value here ?????
  }
}

  class func processMenuHeaders(menu_header: JSON){
    let mh_name=menu_header["name"].stringValue
    println("mh_name: \(mh_name)")
    for (key, subJson) in menu_header["menu_headers"]{
      EKMenu.processMenuHeaders(subJson)
    }
  }

但是我实际上如何在这里退货？我99％确信它是某种类型的完成处理程序，但是对于Swift和Alamofire来说，这是我的新手，我有点迷失了。我见过我不会能够在Swift中使用Alamofire返回值，但是知道其中某些值很快就会过期（例如，Swift 1.1）

but how do I actually return something here? I am 99% sure that it's some type of completion handler but, being new to Swift and Alamofire, I'm a bit lost. I've seen I won't be able to return a value with Alamofire in Swift but know that some of this is going out of date very quickly (ie Swift 1.1)

推荐答案

getMenu函数的完成处理程序示例，假设菜单是您要返回的值：

An example of a completion handler for your getMenu function, assuming menu is the value you want to "return":

class MenuManager {

    // the handler takes an EKMenu argument
    class func getMenu(menu_id: Int, completionHandler: (menu: EKMenu) -> ()) {

        let url="https://www.domain.com/arc/v1/api/menus/\(menu_id)/mobile"
        Alamofire.request(.GET, url).responseJSON() {
            (_, _, data, _) in
            println("within menu request")
            var json=JSON(data!)
            var menu=EKMenu()
            menu.name=json["menu"]["name"].stringValue
            for (key, subJson) in json["menu"]["menu_headers"]{
                EKMenu.processMenuHeaders(subJson)
            }

            // wrap the resulting EKMenu in the handler
            completionHandler(menu)

        }
    }

    class func processMenuHeaders(menu_header: JSON){
        let mh_name=menu_header["name"].stringValue
        println("mh_name: \(mh_name)")
        for (key, subJson) in menu_header["menu_headers"]{
            EKMenu.processMenuHeaders(subJson)
        }
    }

}

MenuManager.getMenu(42, completionHandler: { menu in
    // here the handler gives you back the value
    println(menu)
})

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