CODEWITHSUNDEEP
javafirebasekotlingoogle-cloud-firestore
Rehan
Rehan

Reputation: 181

Finding random (auto) id assigned to our document by Firestore

I know its a bit weird question but how can I access the unique (auto) id google firebase generates for my document whenever I create new document. For example this is my code

val postCollections = db.collection("posts")
val newPost = Post(text, user, currentTime)
postCollections.document().set(newPost)

How can I know that what is the id generated for this document of "newPost" because i want to use that id in my code and at the same time i dont want to send custom id because it won't be unique

Upvotes: 0

Views: 159

Answers (1)

LeadDreamer
LeadDreamer

Reputation: 3499

val postCollections = db.collection("posts")
val newPost = Post(text, user, currentTime)
postCollections.document().set(newPost)

As you've likely discovered, .set() returns a Promise <void> .

But what you've ignored is .set() only operates on a DocumentReference - which is what you get from postCollections.document(). A DocumentReference has properties id and path - it is the .document() that creates a new, unique, documentId.

So:

val postCollections = db.collection("posts")
val newPost = Post(text, user, currentTime)
val newRef = postCollections.document()
newRef.set(newPost)

And now you have the document id (and path) available as properties of newRef.

https://firebase.google.com/docs/reference/js/firebase.firestore.DocumentReference

Upvotes: 2

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