ULCC/iiif_manifest

IIIFManifest

IIIF http://iiif.io/ defines an API for presenting related images in a viewer. This transforms Hydra::Works objects into that format usable by players such as http://universalviewer.io/

Usage

Your application must have an object that implements #file_set_presenters and #work_presenters. The former method should return as set of leaf nodes and the later any interstitial nodes. If none are found an empty array should be returned.

Additionally, it must have a #description method that returns a string.

Additionally it should implement #manifest_url that shows where the manifest can be found.

Additionally it should implement #manifest_metadata to provide an array containing hashes of metadata Label/Value pairs.

Additionally it may implement #sequence_rendering to contain an array of hashes for file downloads to be offered at sequences level. Each hash must contain "@id", "format" (mime type) and "label" (eg. { "@id" => "download url", "format" => "application/pdf", "label" => "user friendly label" }).

Finally, It may implement ranges, which returns an array of objects which represent a table of contents or similar structure, each of which responds to label, ranges, and file_set_presenters.

For example:

 class Book
   def initialize(id, pages = [])
     @id = id
     @pages = pages
   end

   def file_set_presenters
     @pages
   end

   def work_presenters
     []
   end

   def manifest_url
     "http://test.host/books/#{@id}/manifest"
   end

   def description
     'a brief description'
   end
   
   def manifest_metadata
         [
           { "label" => "Title", "value" => "Title of the Item" },
           { "label" => "Creator", "value" => "Morrissey, Stephen Patrick" }
         ]
   end

   def sequence_rendering
     [{"@id" => "http://test.host/file_set/id/download", "format" => "application/pdf", "label" => "Download"}]
   end

   def ranges
     [
       ManifestRange.new(
         label: "Table of Contents",
         ranges: [
           ManifestRange.new(
             label: "Chapter 1",
             file_set_presenters: @pages
           )
         ]
       )
     ]
   end
 end

 class ManifestRange
   attr_reader :label, :ranges, :file_set_presenters
   def initialize(label:, ranges: [], file_set_presenters: [])
     @label = label
     @ranges = ranges
     @file_set_presenters = file_set_presenters
   end
 end

The class that represents the leaf nodes, must implement #id. It must also implement #display_image which returns an instance of IIIFManifest::DisplayImage

  class Page
    def initialize(id)
      @id = id
    end

    def id
      @id
    end

    def display_image
      IIIFManifest::DisplayImage.new(id,
                                     width: 100,
                                     height: 100,
                                     format: "image/jpeg",
                                     iiif_endpoint: endpoint
                                     )
    end

    private

      def endpoint
        IIIFManifest::IIIFEndpoint.new("http://test.host/images/#{id}",
                                       profile: "http://iiif.io/api/image/2/level2.json")
      end
  end

Then you can produce the manifest on the book object like this:

  book = Book.new('book-77',[Page.new('page-99')])
  IIIFManifest::ManifestFactory.new(book).to_h.to_json

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/projecthydra-labs/iiif_manifest. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.