Removing Firebase Realtime Database node using Cloud Function

Question

I can successfully get a query param and post it into my realtime database at a path defined by the query param itself, using this code:

'use strict';

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();

exports.emptyHat = functions.https.onRequest(async (req, res) => {
  // Grab the group parameter.
  const group = req.query.group;
  // Push the new message into the Realtime Database using the Firebase Admin SDK.
  const snapshot = await admin.database().ref('/group').push({list: group});
  // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
  res.redirect(303, snapshot.ref.toString());
});

If the query param was 'test', the result would be a new entry at /test/{firebaseID}/{'list':'test'}

When I tried to modify it to remove the node named in the query parameter I get errors. (I'm trying to remove that top level /test node

'use strict';

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();


exports.emptyHat = functions.https.onRequest(async (req, res) => {
  // Grab the group parameter.
  const group = req.query.group;
  // Remove the node at the location 'group'.
  functions.database().ref('/group').remove();
  // Redirect with 303 SEE OTHER to the URL of the pushed object in the Firebase console.
  //res.redirect(303, snapshot.ref.toString());
});

Error message in the logs:

    at exports.emptyHat.functions.https.onRequest (/srv/index.js:95:13)
    at cloudFunction (/srv/node_modules/firebase-functions/lib/providers/https.js:49:9)
    at /worker/worker.js:783:7
    at /worker/worker.js:766:11
    at _combinedTickCallback (internal/process/next_tick.js:132:7)
    at process._tickDomainCallback (internal/process/next_tick.js:219:9)

Doug Stevenson · Accepted Answer · 2020-04-01 18:58:48Z

1

Your second function is ignoring the promise returned by the Firebase API. This makes it unlikely to work in Cloud Functions. Cloud Functions HTTP triggers require that you only send a response only after all the asynchronous work is complete. After your function generates a response, it will terminate and clean up any async work still in progress. That work might not complete.

Your second function should be more like your first one, and use the promise returned by remove() and wait for it to complete before sending the response:

exports.emptyHat = functions.https.onRequest(async (req, res) => {
  const group = req.query.group;
  await admin.database().ref('/group').remove();
  // send the response here.
});

edited Apr 1, 2020 at 18:58

answered Apr 1, 2020 at 17:32

Doug Stevenson

321k37 gold badges458 silver badges474 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Chris Jacobs Over a year ago

Thank you! I've updated to

exports.emptyHat = functions.https.onRequest(async (req, res) => {   const group = req.query.group;   const snapshot = await functions.database().ref('/group').remove();   // send the response here.   res.redirect(303, snapshot.ref.toString()); });

but still getting this error:

Chris Jacobs Over a year ago

error:

TypeError: functions.database is not a function     at exports.emptyHat.functions.https.onRequest (/srv/index.js:102:36)     at cloudFunction (/srv/node_modules/firebase-functions/lib/providers/https.js:49:9)     at /worker/worker.js:783:7     at /worker/worker.js:766:11     at _combinedTickCallback (internal/process/next_tick.js:132:7)     at process._tickDomainCallback (internal/process/next_tick.js:219:9)

Doug Stevenson Over a year ago

Actually, your code was also incorrect trying to use functions to delete anything. You need to use admin.

Chris Jacobs Over a year ago

that seems to have helped a bit with the errors...! still not working though, getting this in the logs:

TypeError: Cannot read property 'ref' of undefined     at exports.emptyHat.functions.https.onRequest (/srv/index.js:104:30)     at <anonymous>     at process._tickDomainCallback (internal/process/next_tick.js:229:7)

Collectives™ on Stack Overflow

Removing Firebase Realtime Database node using Cloud Function

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related