How to delete image stored in Firebase storage after triggering Firestore onDelete in Cloud Function?
How to delete image stored in Firebase storage after triggering Firestore onDelete in Cloud Function?
I want to use a cloud function background trigger, so when I delete a user data in Firestore, I want to also delete their profile picture in the Firebase storage.
the userID is used as the image name of that picture. and the image is located inside the profilepicture folder
export const removeProfilePictureWhenDeletingUserData = functions.firestore
.document('userss/userID')
.onDelete((snap, context) =>
const userID = context.params.userID
// how to delete the image in here?
);
I have tried to read the documentation, but I am confused about how to implement that method :(. really need your help. thanks in advance
1 Answer
1
The following Cloud Function code will do the job.
// Adapted following Doug's advice in his comment //
....
const admin = require('firebase-admin');
admin.initializeApp();
....
var defaultStorage = admin.storage();
exports.removeProfilePictureWhenDeletingUserData = functions.firestore
.document('users/userID')
.onDelete((snap, context) =>
const userID = context.params.userID;
const bucket = defaultStorage.bucket();
const file = bucket.file('profilePicture/' + userID + '.png');
// Delete the file
return file.delete();
);
See the following doc items for more detail:
https://firebase.google.com/docs/reference/admin/node/admin.storage.Storage
https://cloud.google.com/nodejs/docs/reference/storage/1.7.x/File#delete
Thanks for your precious advice @DougStevenson. So if I understand correctly returning just
file.delete() is the correct way. If I am not mistaking, there was a time when the CF samples were catching errors with return false;. I understand that we don't need to do that anymore for CFs that must return a promise.– Renaud Tarnec
Sep 9 '18 at 18:38
file.delete()
return false;
Yes, just return the promise in this case. I don't recall the history of the official samples (I didn't write them), but they have improved over time.
– Doug Stevenson
Sep 9 '18 at 18:46
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When using the Admin SDK in Cloud Functions, it's not necessary to call out the bucket name if you have only one (the default) in the project. Also, it's an anti-pattern to just log an error if you catch it. The more correct solution is to just return the rejected promise, then Cloud Functions will log it. It will also retry the function if retry is enabled. Returning the promise from catch() will prevent the retry system from working. It's better to return the rejected error unless you really have done something to handle the error.
– Doug Stevenson
Sep 9 '18 at 17:23