Behavior (viewingHint) value "continuous" no longer working

[kirschbombe]

UV version:

 universalviewer@v4.0.21

I'm submitting a:

• bug report => please fork one of these codesandbox examples with a repro of your issue and include a link to it below
• feature request => please use the user stories repo
• support request => Please do not submit support requests here, use stackoverflow

Current behavior:
When loading a Manifest with the viewingHint/behavior "continuous", UV only displays the first image of the sequence.

Expected behavior:
The images in the sequence should display as if stitched together into one long image (either horizontally or vertically depending on viewingDirection.

Steps to reproduce:
Here is the cookbook recipe with a sample Manifest and links to the functionality in Mirador and Theseus (the UV link was removed a while ago since it wasn't working properly, but it was when the recipe was first created): https://iiif.io/api/cookbook/recipe/0011-book-3-behavior/

[demiankatz]

Thanks for the report, @kirschbombe -- it looks like this has been broken for a long time. It works in 3.x, but hasn't worked in any release of 4.x (at least, it's broken in 4.0.0, and it's broken in the latest, which seems like a bad sign for everything in between).

We've been talking about trying to devote some effort to investigating and fixing open bug issues in the coming months, so I have labeled this issue accordingly to be sure it gets some attention. Unfortunately, I suspect this one is not going to be a straightforward/trivial fix, though I'd love to be proven wrong about that! :-)

[kirschbombe]

Thanks for the quick reply! If it's OK, I'm going to remove the UCLA example so I can revert it back to "individuals" for now so all of the images display :) But the cookbook recipe manifest should be enough to test.

I hope it's not an onerous fix!

[jamesmisson]

Possibly related to #627 so I'm just leaving this reminder to myself to look into it when I'm looking at #627

[jamesmisson]

I've had a chance to look into this today and I think it's just a case of UV (and Manifold) not being fully up to date with v3 behaviour. Continuous viewing is determined by the Manifold Helper's isContinuous, and this has so far just checked viewingHint. So that means that v2 manifests with viewingHint: "continuous" still work in UV, e.g.:

https://uv-v4.netlify.app/#?manifest=https://librarylabs.ed.ac.uk/iiif/manifest/mahabharataFinal.json

So to get started fixing this, I've begun a PR in Manifold to check the behavior as well as the viewingHint: IIIF-Commons/manifold#64

[kirschbombe]

Hi, @jamesmisson - the UCLA v2 manifests with continuous are not working either - that was the original example I used for this ticket. These same UCLA manifests displayed correctly before UV v4.x, so I think there is still something going on for v2, not just v3. If v3 gets fixed, I can live with migrating our v2 manifests with continuous to v3 though :)

UCLA v2 example: https://digital.library.ucla.edu/catalog/ark:/21198/zz001nwthk
...and the Manifest: https://iiif.library.ucla.edu/ark%3A%2F21198%2Fzz001nwthk/manifest

[jamesmisson]

Thanks @kirschbombe , that's useful! I think I've identified the problem(s), and have opened a draft PR to get this fixed (still some work to be done which I can return to at the end of next week).