Throbber and message for server data sync

[medikoo]

As reported in https://github.com/egovernment/eregistrations-salvador/issues/1150

[vianneyl]

@medikoo @melux We can also have this in the Part B for each process role, and, for the revision role, have it for each document validation.

[medikoo]

@vianneyl yes we'll assure it automatically appears for every form

[medikoo]

@vianneyl I thought more about that, and I'm not sure whether proposed solution is indeed the best one. There are some factors that need to be taken into account:

User should not feel blocked if data has not been saved to server. He may continue with saving other forms, navigating to other pages, and even closing his browser. As data he input, is saved in local storage of browser, and will be propagated to server as soon as server is accessible again, even if it's in another session.

By providing a throbber we may make him feel blocked to proceed with next section, and I'm not sure if it's right idea, concerning how technically this application works.

It might be better to put some global indicator somewhere in header of a page, some green/yellow/red light bulb that will indicate states: "Some saved data not propagated to the server" (red), "Data in process of propagation" (yellow), "All data propagated" (green). In normal connection it will be just yellow and green indicators, but when there would be problems with connections (or our server would be down) it'll be red.

Such approach, if provided well to user, will give better sense on how this application works.

Let me know.

[vianneyl]

@medikoo We decided on displaying those 2 messages when applicable:

• Your data has been saved locally. Please connect to the internet to save it to the server.
• Your data has been saved. Those 2 messages would be on a notification box on the top-right corner (below the menu).

We would like also to have a throbber when we click on the save button.

[medikoo]

Implementation notes: It requires front-end handling