Fix #12303: Evaluating IIIF metadata values dspace.iiif.enabled and iiif.search.enabled correctly

[marsaoua]

Using the double negation (!!) in

dspace-angular/src/app/core/utilities/item-iiif-utils.ts

Line 16 in ffcca7d

return !!item.firstMetadataValue('dspace.iiif.enabled');

converts the value into a strict boolean. In case of dspace.iiif.enabled = false the check will incorrectly treat false as enabled resulting to the error described in DSpace/DSpace#12303

References

Add references/links to any related issues or PRs. These may include:

• Fixes IIIF viewer not evaluating variable correctly DSpace#12303

Description

False/false, null, and undefined are handled safely. Only True\true is matched.

Instructions for Reviewers

Edit an existing or create an item with a metadata value dspace.iiif.enabled = false

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[nwoodward]

Thanks @marsaoua. This fixes an obvious bug with dspace.iiif.enabled being interpreted incorrectly. I tested it locally, and it fixes the behavior of the IIIF viewer for values like false, null, true, etc.

There is still a problem when an item has the metadata field dspace.iiif.enabled set to to true, but iiif.enabled = false in [dspace]/config/modules/iiif.cfg is set for the entire repository. In that case the IIIF viewer appears on the simple item page even though it shouldn't, and it's empty.

[marsaoua]

@nwoodward Thank you for the review it's much appreciated!

Good point!
In my understanding the viewer is only needed if IIIF is enabled. I guess there may be resons to disable IIIF but keep the viewer running. I will look into it.