CODEWITHSUNDEEP
flutterfirebasedartgoogle-cloud-platformoffline-mode
Haizad Annuar
Haizad Annuar

Reputation: 191

Firebase Flutter Offline Capability - to get accurate timestamp for offline records

Can Firebase get accurate time for offline records which have been stored in device when the device's clock has been changed? The device's clock might be changed when the user rebooted the device or when the user adjusts the date time manually.

My case is quite similar to Get actual DateTime of a device in Offline Mode which I can quote here 1) The application can work in online as well as offline. The app has a feature to create and save the NOTES inside the application. Also, When the app gets internet connection, I need to send the NOTES to backend server. I have a field called 'DATECREATED' in each NOTE (the datetime where the actual NOTE was created) ISSUE: If the User has set the DateTime wrongly in the device, My application sends the incorrect DATETIME to server.

I am going to handle the offline issue on Android and IOS platform, so I came out with another possible solution such as get the GPS time, using some sort of background counter, etc. Based on my experiment, the solution are not reliable enough and some might difficult to do. That's why I decided to get the accurate timestamp using Firebase.

I read a reference https://firebase.google.com/docs/database/flutter/offline-capabilities#clock_skew, but I am not quite sure whether it can help me to get accurate time for offline records.

Upvotes: 1

Views: 254

Answers (1)

Alex Mamo
Alex Mamo

Reputation: 138824

There is no way you can get a server timestamp while offline. Why? Simply because the timestamp is totally generated on the server. And since you're offline and cannot communicate with the server, you cannot get an estimation. So there is no other system that can generate a timestamp other than the Firebase server.

Besides that, a date that can be generated on the client can be manipulated, so you cannot rely on that.

The option that you have in my opinion would be to have two fields. One is for the real timestamp, which you'll be received when you're back online and the other one is what the client provides. In that way, you make a comparison, if this is what you want.

Edit:

Firestore, is a Cloud hosted NoSQL database. So there is no way you can generate an accurate time while the user is offline. What you can certainly do is calculate the period of time while the user is offline. This means that you have to calculate the number of minutes the user has lost connectivity. Let's say a user losses connectivity for 10 minutes, when it regains connectivity, you receive the Firestore timestamp. Now, all you have to do is to subtract those 10 minutes from the received timestamp in order to have the accurate time that you're looking for.

Upvotes: 2

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