How to check if a cloud firestore document exists when using realtime updates

Question

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?

Answer 1

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

Answer 2

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());    }