Accessing Firestore Document data within JavaScript https on request function-CodePudding

I am working on a piece of my app where I need to make a call to a Firebase Function, which parses through Firestore data to return a dictionary that I will use to populate UI in Swift.

My function is declared as so: exports.getUIBetData = functions.https.onRequest( (request, response) => {

This function takes in a userID as body parameter. Then, I need to hit firebase to get a specific document's data tied to this userId and perform some actions on it. I believe I am running into some issues with the async functionality behind getting data from a document, as I keep getting errors or simple promises that haven't been resolved. Here is my query:

const body = request.body;
const userId = body.data.userId;
  const bettorIdDoc = admin.firestore()
      .collection("user_dim").doc(userId).get().data();

I can confirm that "user_dim" is a valid collection, and the userId is a key to a document within it. However, I can't access the fields tied to this doc.

I was originally trying with just .data(), and realized from the official documentation that you need to do .get().data(), however this is async. How do I handle the async nature when I am attempting to do this within my main function (exports.getUIBetData = functions.https.onRequest( (request, response) => {)?

Error: TypeError: admin.firestore(...).collection(...).doc(...).get(...).data is not a function

CodePudding user response：

Loading data from Firestore (and pretty much any cloud API) is an asynchronous operation. You can see this by checking the return type of get(), which is Promise<DocumentSnapshot> and not just DocumentSnapshot.

This means you'll have to use then or await (if you're in an async context) to be able call data():

const bettorIdRef = admin.firestore()
   .collection("user_dim").doc(userId)
ref.get().then((snapshot) => console.log(snapshot.data());