firebase functions: automatically update fields

June 6, 2023

In my app I’ve been able to automatically update a single field using firebase function with this code:

const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();
const database = admin.firestore();
const path = "ADS/3rVdtNp4RfMXUXFj5ElNOjjcMuT2";
exports.scheduled = functions.pubsub.schedule("* * * * *").onRun((context) => {
  database.doc(path).update({"updateTime": admin.firestore.Timestamp.now()});
  return console.log("Successfully Updated"+admin.firestore.Timestamp.now());
});

This works perfectly as in the picture. But it’s for a single ID.

I however, want to write the code that will apply to all the ID’s and any future ID that will that may appear later. I tried the following codes as suggested by someone from this platform almost three years ago. But it didn’t help.

const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();
const database = admin.firestore();
exports.scheduled = functions.pubsub.schedule("* * * * *").onRun((context) => {
  database.collection("ADS").get().then((snapshot) => {
    snapshot.forEach((doc)=>doc.update({t: admin.firestore.Timestamp.now()}));
  });
});

I also used this link but I didn’t really understand it.
link to schedule function

Any help, please?

>Solution :

Instead of updating your document in each loop iteration you should considerate using batch writes.

const functions = require("firebase-functions");
const admin = require("firebase-admin");
admin.initializeApp();
const database = admin.firestore();

exports.scheduled = functions.pubsub.schedule("* * * * *").onRun(async (context) => {
  const batch = database.batch()
  const {docs} = await database.collection("ADS").get()
  docs.map(doc => {
    batch.set(
      database.doc(`ADS/${doc.id}`),{
         updateTime: admin.firestore.Timestamp.now()
      }, {
        merge: true
      }
    )
  })

  await batch.commit()
})