problem

Although if we use the maintenance mode, it can happen that a user does have out dated JS source code in the browser.

This can happen if the user log into translate5, then he does nothing (going out to lunch) and in that time, the maintenance starts, the update is done, the maintenance stops. Since the browser makes no request to the server, the GUI does not notice the maintenance mode, therefore no reload, no update of the JS files.

solution

1. Verify if we already have a similar algorithm!
2. If not:
   1. implement, that the GUI always sends the application version as HTTP header in the Ajax requests.
   2. On the server side check for that version, if it does not match the server version throw an exception.
   3. In the GUI handle that special exception with a popup and after confirming the popup a reload