How to create UNDO button, flutter firebase-CodePudding

In my project I have a delete button that deletes some data from firebase firestore, what i'm trying to do is showing a snackbar with undo word, when it's pressed the process will be cancelled and no data will be deleted. I haven't found a solution yet. Is it possible?

CodePudding user response：

Deletes in Firestore are permanent; once you delete a document it is gone.

If you want to give the option to undo the deletion, you'll want to:

Either create the document in another collection before deleting it from the main one. For example, a common implementation is to have a subcollection with deleted documents, or even the entire history of each document.
Or you mark the documents as deleted, instead of really deleting them. This type of marking is typically referred to as a tombstone.

CodePudding user response：

You can use a Timer to create a callback that can be canceled anytime before the timer runs out.

import 'dart:async';

void main() {
  
  final cancelable = Timer(Duration(seconds: 5), () {
      // The delete function should be here
      print('canceled after 3 seconds');
    });
    
  Timer(Duration(seconds: 3), cancelable.cancel);
  
}

In this example the print() callback gets canceled after three seconds, but you could pass the cancelable.cancel() function as a callback for the undo button and cancel the deletion on Firestore by clicking it before the Timer runs out