取消订阅 Firestore 文档快照侦听器

Question

Is there a way to unsubscribe to snapshot updates for a listener I have put on a Firestore document? The documentation about this only shows how to unsubscribe to snapshot updates on a collection . It says an unsubscribe function is sent back when the snapshot listener is set. However, it does not look thats the case for snapshot listeners on a document. I dont get any unsubscribe function back, I only get an object that looks like this:

If it counts for anything, I am using the firebase emulator

Answer 1

The onSnapshot method returns a function that, when called, will unsubscribe:

const unsubscribe = firebase.firestore().doc('path/to/some/doc').onSnapshot(...);

// later
unsubscribe();