I am building a mobile app using Flutter. All user's data is stored online in a MySQL database, so the app needs an internet connection for almost every user interaction (there is a backend REST API).
Users have to be able to create some lists of tasks, update and delete every task and list, and so on. But from the user's perspective, the need for an internet connection for every simple operation like adding or deleting a task is a bad experience. I need a way to support these operations even without connection with the backend and to apply these changes later when it is possible. But what is the best practice to handle this case?
How to keep the app behaving like normal even without an internet connection and sync all changes that the user has done with the backend when the internet is available again?
For example, if the user creates a new list the app expects to receive the new list's object (with id) from the backend. Later this id is used for every backend call about this list like adding a task in it.