Handle missing objects gracefully in Open MCT

[shefalijoshi]

Summary

When objects in views are missing, we should not fail but handle the issue gracefully.

Expected vs Current Behavior

Currently several views fail with console errors and Open MCT shows an endless spinner when objects are missing.
We should ensure that views load even when objects are missing.

Impact Check List

• Data loss or misrepresented data?
• Regression? Did this used to work or has it always been broken?
• Is there a workaround available?
• Does this impact a critical component?
• Is this just a visual bug?

Steps to Reproduce

1. In LocalStorage or in CouchDB, create an object / telemetry like a sine wave generator
2. Add this object to several views - Display Layout, Flexible Layout, Telemetry Table, Overlay / Stacked Plots, LAD Tables etc.
3. Delete the object from the persistence storage
4. Lots of console errors are displayed in different views.

Environment

• Open MCT Version: 1.7.8
• Deployment Type: /testathon
• OS: Mac
• Browser: All

Additional Information

[khalidadil]

I'm still seeing a few errors

in a Display Layout:

in a Overlay Plot:

in a Stacked Plot:

[unlikelyzero]

@alizenguyen @shefalijoshi are there 4 or more possible scenarios to test?

1. LocalStorage
2. CouchDB
3. Removed/updated from dictionary
4. Removed/updated from Import/Export

[alizenguyen]

@unlikelyzero I'm not sure exactly how many ways you can remove data, I went with the instructions in the 'steps to reproduce' above.

[akhenry]

@alizenguyen @unlikelyzero Should this be closed for testathon?

[akhenry]

ALMOST fixed :) Just one edge case:

1. Created a sinewave generator object in Couch DB
2. Added the SWG to an overlay plot, stacked plot, display layout (ie. telemetry view), LAD Table, and LAD Table Set
3. From the Couch admin interface, deleted the previously created SWG object
4. Navigated to the various views that include the now deleted object and observed no visual issues.

Verified all cases except for LADTableSet. In the case of LADTableSets the LadTable containing the missing object does not render at all, and the following error appears in the console:

Note that there is still an error message being produced by the LADTableSet:

TypeError: Cannot read properties of undefined (reading 'valueMetadatas')
    at a.hasUnits (LadTableSet.vue?3c5d:86:1)
    at pn.get (vue.min.js?8f59:6:26853)
    at pn.evaluate (vue.min.js?8f59:6:27991)
    at a.eval [as hasUnits] (vue.min.js?8f59:6:29888)
    at a.LadTableSetvue_type_template_id_2afd3da8_render (LadTableSet.vue?4eb8:1:143)
    at e._render (vue.min.js?8f59:6:35545)
    at a.r (vue.min.js?8f59:6:68553)
    at pn.get (vue.min.js?8f59:6:26853)
    at pn.run (vue.min.js?8f59:6:27740)
    at ln (vue.min.js?8f59:6:25804)

Will file a followup issue for a future release to fix this. It appears to be otherwise benign

[akhenry]

Verified fixed. Nice work!