Make exception information more user friendly

From #279. Author: @lresende

Looks like we are receiving more details on the client-side, but I would like to make this a little more user-friendly. Maybe we could get inspired on the old Windows error dialog boxes:

And have something like:

Error title
Error Message ...
Error details in a collapsable section (closed by default)?

In order to accomplish this, we might need to send more specific error details from the backend. In the past, I have accomplished something similar by distilling some of this info into specific response HTTP headers.

[kevin-bates]

Hi @karlaspuldaro - I hope to get some time to look into things on the back end tomorrow. I think we could probably define a mixin class that the back-end handlers can derive from that deals with exception formatting.

Three obvious fields are things like ‘title’, ‘message’ and ‘details’. I’m not sure about ‘error code’ since the handlers don’t necessarily have the context of what happened and trap general exception instances, but I’ll look into the viability of that. If an error code thing is ‘where we want to go with this’ then that usually implies a “registry” of codes, and I’d prefer we not go there outside of the general HTTP error codes (of which only a few are applicable).

At any rate, my plan would be to provide you with a branch on my fork that you can use to develop a front-end solution.

[karlaspuldaro]

Here’s what the most updated version looks like Details collapsed by default: In case we don’t receive a traceback, we won’t see the “Error details:” line/button

Details expanded with auto scroll: