[Table] Unresolved request spins indefinitely

[VWoeltjen]

Observed during VISTA R3.4 testing; a URL used for a historical telemetry request gave a 400 response, but the Telemetry Table continued showing a wait spinner indefinitely afterward.

[aayusharora]

Hi @akhenry Can I work on this issue?
@VWoeltjen Will you please provide some steps to reproduce this issue?

[akhenry]

@aayusharora Please do! I've provided some information below to get you started.

Not sure if it's the exact same issue, but I was able to create similar behavior using the openmct tutorials - https://github.com/nasa/openmct-tutorial . Steps for recreating below.

Once you've got the tutorial up and running (if you haven't already done it, this is also a good way to learn the basics of developing for Open MCT), the following steps will result in a table with a persistent spinner icon -

1. Create a new telemetry table (Create menu -> Telemetry Table).
2. Expand "Example Spacecraft", and drag Generator Temperature into the table.
3. Save the table under My Items
4. Navigate back to My Items
5. Open the Chrome debugger (cmd-opt-i on mac, or ctrl-shift-i on windows) and in the "Network" tab, check the box that says "Offline"
6. Back in Open MCT, navigate to the table you created previously. Observe that the spinner remains indefinitely.

If you go back to the Chrome console you will notice that there are a number of error messages, and one of them relates to a line in the http.js library that we provide with the tutorials.

CAUTION!! Although the bug in http.js should be corrected at some point, it's out of scope for this issue. Fixing this error won't fix the issue as originally reported. http.js is only used by the tutorials, and nowhere else. But...

It does provide a handy way of recreating the issue.

The issue, at its heart, is that the telemetry table is not handling errors gracefully, despite having code specifically for this purpose. Some investigation needs to be done to try and figure out why exceptions such as the one caused by http.js do not trigger the error handling in the telemetry table.

[aayusharora]

Thanks for the explanation @akhenry I will look into it.

[akhenry]

Testing notes:

This fixes an issue in tables where an error would not cause the wait spinner to dismissed from a table. This condition can be reproduced by checking offline in the Network tab of Chrome dev tools and then viewing a table of telemetry data. Previously a wait spinner would display indefinitely.