Get async value from firestore

Question

I am struggling with async operations. I am trying to simply get a value from firestore and storing it in a var.

I manage to receive the value, I can even save it in

Answer 1

Since getValues function returns a promise, you need to await getValues function while calling it.

Change getValues like so -

function getValues(collectionName, docName,) {
  console.log("start")
  var result;
  return db.collection(collectionName).doc(docName).get()
    .then(function (doc) {
      if (doc.exists) {
        console.log("Document data:", doc.data());
        result = doc.data().text;
        console.log(result);
        return result;
      } else {
        // doc.data() will be undefined in this case
        console.log("No such document!");
        result = "No such document!";
        return result;
      }
    }).catch (function (err) {
      console.log('Error getting documents', err);
    });
  };

Then use getValues like so -

helpMessage = await getValues('configuration','helpMessage');

Explanation -

async, await are just syntactic sugar for Promises. async functions return a promise (or AsyncFunction more accurately) which needs to be resolved to use its enclosed value.

See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function