[BUG] Prev/next canvas buttons break

[elynema]

Description

For some records the prev and / or next canvas buttons in the Ramp media player cause the screen to go blank and generate null pointer errors in the developer's console. Dananji thinks it's a bug with markers used in VideoJS to highlight the structure in the progress bar.

Note that this does not necessarily happen when navigating between every canvas on the media object.

Here is an example of what happens after clicking on prev and / or next.

Private Zenhub Image

To Reproduce

Here are some example records that have this issue as you use the prev / next canvas buttons:

• https://avalon-dev.dlib.indiana.edu/media_objects/3n203z084
• https://avalon-dev.dlib.indiana.edu/media_objects/000000000
• https://avalon-dev.dlib.indiana.edu/media_objects/m900nt40f (note, this has multiple sections, but no structure?)

Environment

Mac OS laptop, Chrome, avalon-dev

Release

Avalon 7.7

[elynema]

Could be a simple check to see whether there is structure or it could be some type of merge conflict.

[elynema]

Ready to QA on avalon-dev.

[charumitraravi]

I performed QA on the 3 items mentioned in the bug, and there were no issues.
Although, I could still find the null pointer issue happening for the 4th section in this item - https://avalon-dev.dlib.indiana.edu/media_objects/g158bh28p - and the page becomes blank
@Dananji @elynema

[elynema]

@charumitraravi @Dananji I believe that is a known issue -- the third section on that item is missing derivatives; there is a placeholderCanvas message in the IIIF manifest, but Ramp is not displaying that yet.

Charu, are you sure it's the 4th section? I had the issue with the 3rd section.

[charumitraravi]

@elynema It is the 3rd section. Thanks for noting it.