检查我是否有观察者在Firebase Swift中监听

Question

Before detaching a firebase handle or removing all observers, I want to check if there are observers listening in my app or I want to check if specific handle/observer is listening. How do I achieve this?

Answer 1

I could not find a firebase api to achieve this. I solved it using this workaround

var handle = ref.child("child").observe()

// check if nil before detaching listener
guard self.handle != nil else { return }
self.ref.removeObserver(withHandle: self.handle)

Answer 2

Alternatively,
If you are not setting multiple observers on the same reference, you can simply keep track of all your references with observers and just call removeAllObservers() on each of them. That way you don't have to keep track of handles and worry about checking for nil values.
For example,

var handle = ref.child("child").observe()
handle.removeAllObservers()