CODEWITHSUNDEEP
javascriptfirebasegoogle-cloud-firestore
Huy Jayden Nguyen
Huy Jayden Nguyen

Reputation: 55

Take one specific auto-generated ID of a document in Cloud firestore

I'm new to making a simple website that use cloud firestore as a database. When the user add new data, I let firestore generating the document ID automatically (as the image). Now I want to get that document ID but I have no idea about that. Here is my code:

  db.collection("todos").add({
    content: input.value,
    name: name.value,
    time_update: time
  })
  .then(function(docRef) {
    console.log("Document written with ID: ", docRef.id);
    return documentId = docRef.id // i try to do this but it does not return the documentID outside this promise
  })
  .catch(function(error) {
    console.error("Error adding document: ", error);
  });

image for more understandable

when I use console.log(documentId) outside that promise, it returned "undefined". Please help, thank you!

Upvotes: 2

Views: 255

Answers (1)

Doug Stevenson
Doug Stevenson

Reputation: 317392

You don't need to wait for the callback. You can get a random ID immediately:

const docRef = db.collection("todos").doc()
const id = docRef.id

Then add the data using set():

docRef.set(...)

The random IDs are generated on the client, not on the server.

Upvotes: 1

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