Flutter firestore - Check if document ID already exists

Question

I want to add data into the firestore database if the document ID doesn\'t already exists. What I\'ve tried so far:

// varuId == the ID that is set to the do         


        

Answer 1

To check if document exists in firestore. Trick use .exists method

Firestore.instance.document('collection/$docId').get().then((onValue){
onValue.exists ? //exists : //not exist ;
});