Firebase连接管理器应只返回一个结果 [英] Firebase Connection manager should return only one result

问题描述

以下文档位于以下位置： https ：//www.firebase.com/docs/ios/guide/offline-capabilities.html#section-connection-state

然而，我的实施和测试：

  connectionCheck.observeEventType（.Value，withBlock：{snapshot in 
 let connected = snapshot.value as ？bool 
如果已连接！= nil&& connected！{
 print（Connected）
} else {
 print（Not connected）
 
 
 
 
 
 $ b $ p $ X $的输出注释：
 
 
 未连接
连接
  
如果我关掉了wifi，结果很简单： 
 
 
 未连接
   
解决方案
作为建议，您可能需要添加一些附加功能; 
 
 
 
如果您想了解用户与Firebase的连接，请注意.info / connected路径，如文档中所述。
 
 
我使用的设计模式是设置一个名为isConnected的全局应用程序变量，并将Firebase观察者附加到.info / connected路径。
 
 
然后，在我的应用程序中，无论我需要知道用户是否连接，我都将KVO Observer附加到我的全局isConnected var。
 
 
 
当用户断开连接（或连接）时，Firebase观察者被调用哪些设置isConnected = false（或者true）。
 
 
然后，在我的应用程序中，观察isConnected var的任何地方都会收到断开/连接的通知，并且可以采取适当的措施。
 
 
 
下面是代码 
 
 
  let connectedRef = rootRef.childByAppendingPath（。info / connected）
 
 connectedRef.observeEventType（.Value，withBlock：{snapshot in 
 
 self.isConnected = snapshot.value as！ Bool // KVO属性
 
 //这只是所以你可以看到它正在被设置，删除
 if（self.isConnected == true）{
 print（connected ）
} else {
 print（not connected）
} 
 //测试代码
}）
  
 
I am following documentation located at: https://www.firebase.com/docs/ios/guide/offline-capabilities.html#section-connection-state


However, my implementation and test of:
        connectionCheck.observeEventType(.Value, withBlock: { snapshot in
            let connected = snapshot.value as? Bool
            if connected != nil && connected! {
                print("Connected")
            } else {
                print("Not connected")
            }
        })
The output in Xcode notes:
Not connected
Connected
If however I turn off the wifi, the result is simply:
Not connected
Given I wish to allow actions to occur and present to the user if there is not a connection, how can I ensure that this Firebase listener only returns the correct response once?
解决方案
As a suggestion, you may want to add some additional functionality;

If you want to know about the users connection to Firebase, you should observe the .info/connected path, as stated in the docs.

The design pattern I use is to set up a global app variable called isConnected, and attach a Firebase observer to the .info/connected path.

Then in my app wherever I need to know if the user is connected or not, I attach a KVO Observer to my global isConnected var.

When the user disconnects (or connects), the Firebase observer is called which sets isConnected = false (or true).

Then, any places in my app that are observing the isConnected var is notified of the disconnect/connect and can take appropriate action.

Here's the code
let connectedRef = rootRef.childByAppendingPath(".info/connected")

connectedRef.observeEventType(.Value, withBlock: { snapshot in

  self.isConnected = snapshot.value as! Bool //KVO property

        //this is just so you can see it's being set, remove
        if ( self.isConnected == true ) {
            print("connected")
        } else {
            print("not connected")
        }
        // testing code
})


                        
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