Firebase - 获取对存储在childByAutoID下的值的引用

Question

我一直在关注制作聊天应用程序的教程,该应用程序有单独的"房间",但它只是每个用户的一个中心列表 - 我正在尝试改变它,以便每个用户看到他们自己的房间列表(房间那个他们创造,并由朋友添加他们的房间).

这是处理创建房间并将其添加到列表的代码:

// Create new room
@IBAction func createRoom(_ sender: Any) {
    if let name = newRoomTextField?.text {
        let newRoomRef = roomRef.childByAutoId()
        let roomItem = [
            "name": name
        ]
        newRoomRef.setValue(roomItem)

        // How to add room to user's room?
        let userRef: FIRDatabaseReference = FIRDatabase.database().reference().child("users")
    }
}

private func observeRooms() {
    // Observe method to listen for new channels being written to Firebase
    roomRefHandle = roomRef.observe(.childAdded, with: { (snapshot) -> Void in
        let roomData = snapshot.value as! Dictionary<String, AnyObject>
        let id = snapshot.key
        if let name = roomData["name"] as! String!, name.characters.count > 0 {
            self.rooms.append(Room(id: id, name: name))
            self.tableView.reloadData()
        } else {
            print("Error! Could not decode channel data")
        }
    })
}

创建一个房间时,我想将新创建的房间添加到Firebase中用户的"房间"节点(我将尝试用它来创建用户的参与房间列表),但每个用户都有使用创建的唯一ID childByAutoID,因此我不确定如何访问它.这就是我的Firebase数据库结构的样子:

{
  "rooms" : {
    "-KgK418WuJGjYw27Tg1-" : {
      "messages" : {
        "-KgK42e1zl3xxUS0E0C0" : {
          "senderId" : "2q4VCKu1e7hiL84ObdzgQcQ0pH63",
          "senderName" : "Timothy",
          "text" : "Hi"
        },
        "-KgK45LTf3R439mOMpvE" : {
          "senderId" : "2q4VCKu1e7hiL84ObdzgQcQ0pH63",
          "senderName" : "Timothy",
          "text" : "Testing"
        }
      },
      "name" : "Room One"
    }
  },
  "users" : {
    "-KgK3zXgap-iRFsbpv8D" : {
      "gender" : "male",
      "handle" : "TestHandle123",
      "name" : "Timothy",
      "profilePicture" : "https://graph.facebook.com/*removed for privacy*/picture?type=large&return_ssl_resources=1",
      "rooms" : {
        "roomName" : ""
      }
    }
   }
}

如何将房间正确添加到在Firebase中创建房间的用户？

编辑:

试过这个

        let userRef: FIRDatabaseReference = FIRDatabase.database().reference().child("users")
        let key = userRef.key
        let childUpdates = ["/\(key)/rooms/": roomItem]
        userRef.updateChildValues(childUpdates)

它最终在"用户"下创建了第二个节点,而不是在该特定用户中.

{
  "rooms" : {
    "-KgKS0VN65GS2r-Cz6K0" : {
      "name" : "Room Two"
    }
  },
  "users" : {
    "-KgKS-X63uSOMnpDWtDn" : {
      "gender" : "male",
      "handle" : "TestHandle123",
      "name" : "Timothy",
      "profilePicture" : "https://graph.facebook.com/*removed for privacy*/picture?type=large&return_ssl_resources=1"
        },
    "users" : {
         "rooms" : {
            "name" : "Room Two"
          }
        }
      }
    }

Answer 1

您应该阅读文档,以下是如何存储该密钥:

let key = ref.child("posts").childByAutoId().key