IIIF Manifest Service

Specification Draft:

• This service returns a specification conformant JSON IIIF Manifest from a web application query request.
• The service response will return either:
• a static Manifest resource from a known URI e.g.
• <http://m.blumenbach.org/static/manifest_601.json>
  OR
• a query generated object based on an a Fedora RDF resource identifier e.g.
  • <http://f.blumenbach.org/fcrepo/rest/<edition>/{id}/manifest>

Manifest SPARQL CONSTRUCT query

• The query request is a parameterized API call
• (e.g. http://blumenbach.org/<datasource>?subject=<subject>&template=manifest )
• The service routes the template parameter to a datasource with a matching query template.
• template options: [manifest, canvas, range, layer]
• Only one <resource> is allowed for the SPARQL CONSTRUCT query.
• The service then with an XHR calls the SPARQL endpoint with an Accept: JSON-LD header and POSTs the query.

JSON-LD Response Transformation

• The endpoint JSON-LD response is transformed by the service in a multi-step process:

1. compacted
   [compacted example]: gist
2. framed
   [framed example]: gist
3. "de-normalized"

The de-normalization involves parsing the object, removing blank node @id references, replacing prefixed elements with aliases, removing rdf:first and rdf:rest elements, and serializing and validating the output as JSON.

• The serialized JSON output response should conform exactly to the IIIF standard that dictates the expectations of the client viewer. typical manifest example

Problem

• The complexity of the "de-normalization" of JSON-LD lists.
• For large manifests, SPARQL CONSTRUCT is a very expensive query operation.

Solution

• Use the Linked Data Fragments Client SPARQL iterator to traverse "typed" RDF sequences and assemble them as javascript arrays:
• example chaining
  ?subject -> ?object -> ?subject and pushing the ?objects.
• the array is then framed into JSON according to the "type" of the sequence.
  • list types include: sequences (ranges), canvases, images, lists

All Objects in IIIF Manifest

<img src="https://github.com/blumenbach/iiif-manifest-service/blob/master/spec/objects-all.png"alt="" />