从insert getdocuments的getdocument获取数组中的0值

Question

我与Firestore合作我有两个结构 一个叫做历史 另一个叫购物车 只是历史结构是

struct UserOrderHistoryModel {
    var id : String? = ""
    var dateOrderCreated : String? = ""
    var cartArray : [CartItemModel]
}

struct CartItemModel {
    var id : String? = ""
    var restaurantImageUrl : String
    var restaurantTitle : String
    var menuItemImageUrl : String
    var menuItemTitle : String
    var countOfMenuItemSelected : Int
}

我要执行的操作是加载历史记录，因此我使用getdocument获取ID和日期

我想获取历史记录文件中的订单集合 所以我在第一个里面使用了另一个getdocuments

func loadUserOrderHistory(completion : @escaping (_ error :Error? ,_ userHistoryArray : [UserOrderHistoryModel]?) -> ()) {

    var historyArray = [UserOrderHistoryModel]()


    let userHistoryRef = USERS.document(UserConfigurations.currentUserID!).collection("history")

    userHistoryRef.getDocuments { (snapShots, error) in

        if error != nil {
              completion(error , nil)
        }else {

            historyArray.removeAll()

            for document in snapShots!.documents {

                let historyId = document.documentID
                let historyData = document.data()
                let historyDate = historyData["date_order_created"] as? Timestamp ?? nil

                let historyDateToString = String(describing: historyDate?.dateValue())

                var orderArray = [CartItemModel]()

                self.loadUserHistoryOrders(histroyDocumentReference: userHistoryRef.document(historyId), completion: { (error, cartArray) in

                    if error != nil {
                        print(error!)
                    }else {
                        orderArray = cartArray!
                    }

                })

                let userHistory = UserOrderHistoryModel(id: historyId, dateOrderCreated: historyDateToString , cartArray: self.orderArray)

                historyArray.append(userHistory)

            }

            completion(nil , historyArray)
        }
    }

}


private  func loadUserHistoryOrders( histroyDocumentReference : DocumentReference, completion : @escaping (_ error : Error? ,_ historyOrders : [CartItemModel]? ) -> ())  {

var cartArray = [CartItemModel]()

histroyDocumentReference.collection("orders").getDocuments  { (snapShot, error) in
    if error != nil {
        completion(error,nil)
    }else {

        for document in snapShot!.documents {

            let id = document.documentID

            let cartDictionary = document.data()

            let restaurantImageUrl = cartDictionary["restaurant_imageurl"] as? String ?? "none"
            let restaurantName = cartDictionary["restaurant_title"] as? String ?? "none"
            let menuItemImageUrl = cartDictionary["menuItem_imageurl"] as? String ?? "none"
            let menuItemName = cartDictionary["menuItem_title"] as? String ?? "none"
            let count = cartDictionary["number_of_selected_menuitem"] as? Int ?? 0

            let cart = CartItemModel(id: id, restaurantImageUrl: restaurantImageUrl, restaurantTitle: restaurantName, menuItemImageUrl: menuItemImageUrl, menuItemTitle: menuItemName, countOfMenuItemSelected: count)

            cartArray.append(cart)
        }

        completion(nil , cartArray)
    }
  }
}

第二个getdocumnet中的orderArray，我将它放在另一个名为loadUserHistoryOrders的函数中

我调试了代码，发现 一旦我到达该函数的末尾，orderArray将返回到0值

这是我的消防站的照片

图片网址：https://drive.google.com/open?id=1NX8NIUN2Yb9m3_7A8EnZgAxWe8xuhNDh

更新： 我通过在第二个方法loadUserHistoryOrders的调用内添加loadUserOrderHistory完成来解决了这个问题

    func loadUserOrderHistory(completion : @escaping (_ error :Error? ,_ userHistoryArray : [UserOrderHistoryModel]?) -> ()) {

    var historyArray = [UserOrderHistoryModel]()


    let userHistoryRef = USERS.document(UserConfigurations.currentUserID!).collection("history")

    userHistoryRef.getDocuments { (snapShots, error) in

        if error != nil {
              completion(error , nil)
        }else {

            historyArray.removeAll()

            for document in snapShots!.documents {

                let historyId = document.documentID
                let historyData = document.data()
                let historyDate = historyData["date_order_created"] as? Timestamp ?? nil

                let historyDateToString = String(describing: historyDate?.dateValue())

                var orderArray = [CartItemModel]()

                self.loadUserHistoryOrders(histroyDocumentReference: userHistoryRef.document(historyId), completion: { (error, cartArray) in

                    if error != nil {
                        print(error!)
                    }else {
                        orderArray = cartArray!

                       let userHistory = UserOrderHistoryModel(id: historyId, dateOrderCreated: historyDateToString , cartArray: self.orderArray)

                       historyArray.append(userHistory)

                       completion(nil , historyArray)

                    }

                })



            }


        }
    }

}