我如何在firebase .ref闭包内部访问变量并在外部使用它们

Question

I declared a variable inside a firebase function i would like to use it outside of the function. I already declare the variable outside of the function and then set it inside of the firebase function but Im still not able to retrieve how can i process this.

let ref = firebasehelper.firebaseURL()
    var userDict = [String:String]()
    var name:String!

override func viewDidLoad() {
    super.viewDidLoad()

    ref.childByAppendingPath("backend/posts").queryOrderedByChild("jobOfferFromId").queryEqualToValue(ref.authData.uid).observeEventType(.ChildAdded, withBlock: {snapshot in


     self.name =  snapshot.value["jobDescribe"] as! String


 // work greate in here
        print(self.name)


    })

    // does not work outside of the Firebase function I want to access the data out here
        print(self.name)

}

Answer 1

that is because you do the print(self.name) before you have the data back from Firebase.

You could put the query in viewWillAppear and then do the print(self.name) in viewDidAppear or viewDidLoad. best would be to actually use the closure and only trigger the next step (print) once the data is back, so by putting a reference to a function (with the print(self.name) or any other use you have for the data) outside viewDidLoad.

Answer 2

在类中创建一个func ，然后将该func放在类中，这将允许您在函子中设置该变量