Add Unsplash illustration collection mode (and fix import)

[k4m454k]

This PR updates the Unsplash plugin so it can load not only regular photos, but also Unsplash illustration assets from collections.

Previously, the plugin used /photos/random when no search query was provided. That works for photo collections, but Unsplash does not return asset_type: illustration items through that endpoint. Collections that contain only illustrations therefore failed with No photos found, even though /collections/{id}/photos returned valid items.

The plugin now supports an explicit content type setting:

• Photos keeps the existing behavior.
• Illustrations from collections loads only asset_type: illustration items.
• Photos and illustrations from collections loads both photos and illustrations.

Key Changes

• Added asset_type handling in src/plugins/unsplash/unsplash.py.
• Preserved existing photo behavior via:
  • /search/photos when search_query is set.
  • /photos/random otherwise.
• Added collection-based loading for illustration and mixed modes using:
  • /collections/{collection_id}/photos
• Added support for multiple comma-separated collection IDs.
• Added filtering by asset_type.
• Added image URL fallback order:
  • selected size (regular on low-resource devices, full otherwise)
  • regular
  • small
  • full
  • raw
• Added clear runtime errors for invalid combinations:
  • illustration or mixed without collections.
  • illustration or mixed with search_query.
  • collections with no matching assets.
• Updated src/plugins/unsplash/settings.html with a new Content Type select.
• Added tests/test_unsplash_plugin.py covering the new behavior.

Behavior Notes

• Illustration support intentionally uses the documented collection photos endpoint rather than an undocumented /illustrations/random endpoint.
• Search remains photo-only because Unsplash’s documented public search endpoint is /search/photos.
• In collection-based illustration and mixed modes, orientation is passed through, but color is not sent because the collection photos endpoint does not document a color parameter.
• No separate SVG/vector conversion is needed: Unsplash returns raster image URLs in urls.regular, urls.full, etc., and the existing image loader already downloads and converts them through Pillow.

Testing
Ran:

PYTHONDONTWRITEBYTECODE=1 python3 -m unittest tests.test_unsplash_plugin -v

Result:

Ran 5 tests in 0.054s

OK

Covered scenarios:

• Existing photo random endpoint behavior is preserved.
• Illustration mode uses collection endpoint and selects only illustrations.
• Mixed mode combines photos and illustrations across multiple collections.
• Illustration mode rejects search_query.
• Empty/no-match illustration collections produce a clear error.

[saulobenignoBraza]

Where can I find the collection ID? I can't seem to find it anywhere on the Unsplash website. All collections appear to be identified by name now

[k4m454k]

Where can I find the collection ID? I can't seem to find it anywhere on the Unsplash website. All collections appear to be identified by name now

The collection ID is the part immediately after /collections/ in the URL. For example, in /collections/QZU1xPqbVYM/its-getting-dark, the ID is QZU1xPqbVYM. I’ll update the helper text to make this clearer.

[saulobenignoBraza]

Got it, thanks for the explanation

It worked with numeric IDs, for example:
https://unsplash.com/pt-br/cole%C3%A7%C3%B5es/3660951/world
https://unsplash.com/pt-br/cole%C3%A7%C3%B5es/4885435/pastel

But IDs containing underscores, hyphens, or letters failed, for example:

https://unsplash.com/pt-br/cole%C3%A7%C3%B5es/2_1SzDWjSSs/travel
https://unsplash.com/pt-br/cole%C3%A7%C3%B5es/_GoY-Muh7Po/business

The example you gave also did not work for me: QZU1xPqbVYM

/collections/QZU1xPqbVYM/its-getting-dark

The error I get is:

Error! An error occurred: Failed to fetch image from Unsplash API, please check logs