Nsryjdtyk

When a child is updated or created in firebase database, I need to trigger a REST API. How to go about it?
Tried using "stream" function, but in order to invoke stream everysec will have to create a cron job. I would like some trigger to be done through firebase to call API.

If you are using the Firebase Realtime database you can use Cloud Functions that trigger on a write to your database. Here is some docs that explain it a bit more. An example from the docs is below. Basically on a create to the database at /messages/{pushId}/original it will trigger this code that you could process your logic in or call your rest api. You can also do this with Firestore as well.

exports.makeUppercase = functions.database.ref('/messages/{pushId}/original')

    .onCreate((snapshot, context) => {

      // Grab the current value of what was written to the Realtime Database.

      const original = snapshot.val();

      console.log('Uppercasing', context.params.pushId, original);

      const uppercase = original.toUpperCase();

      // You must return a Promise when performing asynchronous tasks inside a Functions such as

      // writing to the Firebase Realtime Database.

      // Setting an "uppercase" sibling in the Realtime Database returns a Promise.

      return snapshot.ref.parent.child('uppercase').set(uppercase);

    });

https://firebase.google.com/docs/reference/js/firebase.database.Reference#on

const ref = firebase.database().ref("node/you/want/to/observe");

ref.on('value', function(dataSnapshot) { //here you do your API call });

BTW - you don't have to 'invoke stream every sec'. You create on listener that will trigger whenever condition is met. Juts remember to turn it off when you're done.