Firebase dataSnapshot 子节点

Question

我正在尝试对用户的购物清单进行快照。快照工作正常，除了产品节点。

Link 到数据库：

这是我的观察员：

func observeLists(callBack: @escaping (_ list: [List]) -> Void){
        let dbRef = database.child("list").child(ShareData.shared.userId)
        
        dbRef.queryOrdered(byChild: "completed").observe(.value, with: { snapshot in
            var newItems: [List] = []
            for child in snapshot.children {
                if let snapshot = child as? DataSnapshot {
                    let groceryItem = List(snapshot: snapshot)
                    newItems.append(groceryItem)
                }
            }
            callBack(newItems)
        })
    }

这是我从 struct List

初始化（快照）

init(snapshot: DataSnapshot) {
        
        let id = snapshot.key
        let value = snapshot.value as? NSDictionary
        let products = value?["products"] as? [Product] ?? []
        let completed = value?["completed"] as? Bool ?? false
        let storeId = value?["storeId"] as? String ?? ""
        let name = value?["name"] as? String ?? ""

        self.init(id, products, completed, storeId, name)
    }

Answer 1

您数据库中的 products 节点不是产品数组 ([Product])，而是 dictionary/map ([String: Product])。

Firebase dataSnapshot 子节点

Firebase dataSnapshot sub-node

firebase

swift

firebase-realtime-database