MBS-8967: Add modal to show errors when trying to change sth

[sh-csg]

Implements #14

[sh-csg]

Failing GHA is not related to this PR

[PhMemmel]

This fixes part of the issue when trying to do for example things you aren't allowed to.

However, the error handling should be implemented for every webservices call, also for the permanent update polls for example. Currently, if for testing purposes I insert an exception into get_kanban_content_update the app will just crash.

The error handling should properly handle the issue of connection loss.

Maybe it's also possible/easier to use displayException function?

[sh-csg]

Added an alert for displaying connection loss.

[PhMemmel]

I left a few comments. Have not tested yet.

[PhMemmel]

Seems to work well so far, good job!

Would it be difficult to implement a feedback for actions the user is doing? If he tries to create a card for example there is no feedback if this action is being queued or it's just being ignored or what happens with it.

Another solution would be to disable the UI completely until the connection is back up.

Thoughts?

[sh-csg]

Seems to work well so far, good job!

Would it be difficult to implement a feedback for actions the user is doing? If he tries to create a card for example there is no feedback if this action is being queued or it's just being ignored or what happens with it.

Another solution would be to disable the UI completely until the connection is back up.

Thoughts?

Yes

[PhMemmel]

Would it be difficult to implement a feedback for actions the user is doing? If he tries to create a card for example there is no feedback if this action is being queued or it's just being ignored or what happens with it.
Another solution would be to disable the UI completely until the connection is back up.
Thoughts?

Yes

What a pity! Then I'll raise a separate ticket for this ;-)

[PhMemmel]

In theory we would have to wrap each ajax with a try catch to avoid all JS console errors. The major ones now have been wrapped, rest is fine for throwing JS console errors when there's a big red banner showing that connection has been lost :)