This works:
db.collection('users').doc('id').get()
.then((docSnapshot) => {
if (docSnapshot.exists) {
db.collection('users').doc('id')
.onSnapshot((doc) => {
// do stuff with the data
});
}
});
... but it seems verbose. I tried doc.exists, but that didn't work. I just want to check if the document exists, before subscribing to realtime updates on it. That initial get seems like a wasted call to the db.
Is there a better way?
Your initial approach is right, but it may be less verbose to assign the document reference to a variable like so:
const usersRef = db.collection('users').doc('id')
usersRef.get()
.then((docSnapshot) => {
if (docSnapshot.exists) {
usersRef.onSnapshot((doc) => {
// do stuff with the data
});
} else {
usersRef.set({...}) // create the document
}
});
Reference: Get a document
Please check following code. It may help you.
const userDocRef = FirebaseFirestore.instance.collection('collection_name').doc('doc_id');
const doc = await userDocRef.get();
if (!doc.exists) {
console.log('No such document exista!');
} else {
console.log('Document data:', doc.data());
}
I know its late, but it's actually snapshot.empty not snapshot.exists . snapshot.empty checks if a doc exists and returns accordingly. happy coding 😊