Investigation needed: Alt text for images

[chrisrlc]

Questions came up during stakeholder meeting:

• Do images have alt text?
  • If so, how is that alt text generated?
  • How difficult would it be to give curators/admins the ability to apply their own alt text rather than automatically pulling from existing metadata fields?

Preliminary investigation: elements seem to have alt text automatically generated from item title. Example: https://exhibits.library.cornell.edu/vintage-vision <img class="img-thumbnail" alt="Billiards scene" src="https://exhibits.library.cornell.edu/images/16/full/!400,400/0/default.jpg">

But elements that display in the individual item pages do not have the right aria labels. Example: https://exhibits.library.cornell.edu/vintage-vision/catalog/5-14 <canvas width="553" height="498" style="..."></canvas>

Related to #526

[chrisrlc]

For images that are directly uploaded to feature pages (vs embedded exhibit items), image alt text comes from the optional "caption" field, but there may be a bug here where this alt text only populates if both the "caption" AND "Link URL" fields are filled in?

[chrisrlc]

Note from Emily!: Regarding alt-text for embedded exhibit items, is there a way to change the field that's pulled from? Most titles will match that of the item in our own catalogue. But this means that we may often have to use titles that are not descriptive and do not meet best practices for alt-text.

[chrisrlc]

Handled in https://culibrary.atlassian.net/issues/LP-476

This will also soon be handled in spotlight core code, and the overrides from LP-476 can be removed.