如何將數據傳遞給從Firebase中檢索信息的閉包？

Question

我試圖將我從我的firebase數據庫檢索到的數據傳遞到我的單身人員的字段中。數據通過閉包接收，並在該閉包中傳遞一些數據到我的單身人士的屬性。如果我在封閉內部打印數據結構（在分配了所有東西之後），我得到了我期望的輸出，但是如果我在所有數據傳入之後將其打印在初始化程序的末尾，則它是空的。

import Foundation 
import Firebase 

class EmployeeList { 
    static let sharedInstance = EmployeeList() 
    var employeeDictionary: [String: [EmployeeData]] 
    var ref: DatabaseReference! 

    private init() { 
     employeeDictionary = [String: [EmployeeData]]() 
     ref = Database.database().reference() 

     ref.child("employeeList").observeSingleEvent(of: .value, with: { snapshot in 
      if let dictionary = snapshot.value as? [String: [String: AnyObject]] { 
       for subsection in dictionary { 
        var subsectionEmployees: [EmployeeData] = [] 

        for item in subsection.value { 
         self.ref.child("employeeList/\(subsection.key)/\(item.key)").observeSingleEvent(of: .value, with: { employeeSnapshot in 
          let employeeObject = EmployeeData(snapshot: employeeSnapshot) 
          subsectionEmployees.append(employeeObject) 
          self.employeeDictionary[subsection.key] = subsectionEmployees 
          //print(self.employeeDictionary) This print statement prints out the expected data every time another employee is appended 
         }) 
        } 
       } 
      } 
      //print(self.employeeDictionary) This print statement prints an empty data structure 
     }) 
    } 
} 

Answer 1

得到火力地堡數據如下

var messagedata = [String:AnyObject]() 

let databaseReff = Database.database().reference().child("message") 

databaseReff.queryOrdered(byChild: "fromId").queryEqual(toValue: self.recieverId).observe(.value, with: { snapshot in 
     if snapshot.exists(){ 
      self.messagedata = snapshot.value! as! [String : AnyObject]   
      self.getAllMessagesSent(snapshot: self.messagedata) 
     } else 
      self.getAllMessagesSent(snapshot: self.messagedata) //Function Created 
     } 
}) 

傳球Clousre獲取到字典和數據字典傳遞給一個函數，做你想做的事，或者使用轉義塊什麼

func getAllMessagesSent(snapshot: [String:AnyObject]) { 
    //data is here 
}