Merge pull request #5 from samvera-labs/ranges

Add support for Structural Metadata.

.rubocop_todo.yml

@@ -38,6 +38,10 @@ RSpec/VerifiedDoubles:
   Exclude:
     - 'spec/lib/iiif_manifest/display_image_spec.rb'
 
+RSpec/ExampleLength:
+  Exclude:
+    - 'spec/lib/iiif_manifest/manifest_factory_spec.rb'
+
 # Offense count: 20
 Style/Documentation:
   Exclude:
@@ -56,6 +60,7 @@ Style/Documentation:
     - 'lib/iiif_manifest/manifest_builder/record_property_builder.rb'
     - 'lib/iiif_manifest/manifest_builder/resource_builder.rb'
     - 'lib/iiif_manifest/manifest_builder/sequence_builder.rb'
+    - 'lib/iiif_manifest/manifest_builder/structure_builder.rb'
     - 'lib/iiif_manifest/manifest_builder.rb'
     - 'lib/iiif_manifest/manifest_factory.rb'
     - 'lib/iiif_manifest/manifest_service_locator.rb'
@@ -67,6 +72,10 @@ Style/MethodMissing:
   Exclude:
     - 'lib/iiif_manifest/manifest_builder/composite_builder.rb'
 
+Metrics/ClassLength:
+  Exclude:
+    - 'lib/iiif_manifest/manifest_service_locator.rb'
+
 # Offense count: 1
 # Cop supports --auto-correct.
 # Configuration parameters: MinSize, SupportedStyles.

README.md

@@ -11,7 +11,12 @@ 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. 
 
-Finally, 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" }`). 
+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:
 
@@ -37,10 +42,33 @@ For example:
     def description
       'a brief description'
     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
 ```
 

iiif_manifest.gemspec

@@ -27,4 +27,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rspec', '~> 3.0'
   spec.add_development_dependency 'rubocop'
   spec.add_development_dependency 'rubocop-rspec'
+  spec.add_development_dependency 'pry-byebug'
 end

lib/iiif_manifest/manifest_builder.rb

@@ -9,6 +9,7 @@
 require_relative 'manifest_builder/record_property_builder'
 require_relative 'manifest_builder/resource_builder'
 require_relative 'manifest_builder/sequence_builder'
+require_relative 'manifest_builder/structure_builder'
 
 module IIIFManifest
   class ManifestBuilder

lib/iiif_manifest/manifest_builder/structure_builder.rb

@@ -0,0 +1,76 @@
+module IIIFManifest
+  class ManifestBuilder
+    class StructureBuilder
+      attr_reader :record
+      def initialize(record)
+        @record = record
+      end
+
+      def apply(manifest)
+        top_ranges.each_with_index do |top_range|
+          manifest['structures'] ||= []
+          manifest['structures'] = RangeBuilder.new(top_range, record, true).apply(manifest['structures'])
+        end
+        manifest
+      end
+
+      def top_ranges
+        record.try(:ranges) || []
+      end
+    end
+    class RangeBuilder
+      attr_reader :record, :parent
+      delegate :file_set_presenters, to: :record
+      def initialize(record, parent, top = false)
+        @record = record
+        @parent = parent
+        @top = top
+        build_range
+      end
+
+      def path
+        "#{parent.manifest_url}/range/r#{index}"
+      end
+
+      def index
+        @index ||= SecureRandom.uuid
+      end
+
+      def apply(manifest)
+        manifest << range
+        sub_ranges.map do |sub_range|
+          manifest = sub_range.apply(manifest)
+        end
+        manifest
+      end
+
+      def build_range
+        range['@id'] = path
+        range['label'] = record.label
+        range['viewingHint'] = 'top' if top?
+        range['ranges'] = sub_ranges.map(&:path)
+        range['canvases'] = canvas_builders.map(&:path)
+      end
+
+      def sub_ranges
+        @sub_ranges ||= record.ranges.map do |sub_range|
+          RangeBuilder.new(sub_range, parent)
+        end
+      end
+
+      def canvas_builders
+        @canvas_builders ||= file_set_presenters.map do |file_set_presenter|
+          CanvasBuilder.new(file_set_presenter, parent)
+        end
+      end
+
+      def range
+        @range ||= IIIF::Presentation::Range.new
+      end
+
+      def top?
+        @top
+      end
+    end
+  end
+end

lib/iiif_manifest/manifest_service_locator.rb

@@ -39,6 +39,7 @@ def manifest_builders
         composite_builder_factory.new(
           record_property_builder,
           sequence_builder,
+          structure_builder,
           composite_builder: composite_builder
         )
       end
@@ -82,6 +83,10 @@ def record_property_builder
         ManifestBuilder::RecordPropertyBuilder
       end
 
+      def structure_builder
+        ManifestBuilder::StructureBuilder
+      end
+
       def sequence_builder
         InjectedFactory.new(
           ManifestBuilder::SequenceBuilder,

spec/lib/iiif_manifest/manifest_factory_spec.rb

@@ -27,6 +27,24 @@ def work_presenters
       def manifest_url
         "http://test.host/books/#{@id}/manifest"
       end
+
+      def ranges
+        @ranges ||=
+          [
+            ManifestRange.new(label: 'Table of Contents', ranges: [
+                                ManifestRange.new(label: 'Chapter 1', file_set_presenters: [])
+                              ])
+          ]
+      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
 
     class DisplayImagePresenter
@@ -74,6 +92,22 @@ def display_image
         expect(IIIFManifest::ManifestBuilder::CanvasBuilder).to have_received(:new)
           .exactly(1).times.with(file_presenter, anything)
       end
+      it 'builds a structure if it can' do
+        allow(book_presenter).to receive(:file_set_presenters).and_return([file_presenter])
+        allow(book_presenter.ranges[0].ranges[0]).to receive(:file_set_presenters).and_return([file_presenter])
+
+        expect(result['structures'].length).to eq 2
+        structure = result['structures'].first
+        expect(structure['label']).to eq 'Table of Contents'
+        expect(structure['viewingHint']).to eq 'top'
+        expect(structure['canvases']).to be_blank
+        expect(structure['ranges'].length).to eq 1
+        expect(structure['ranges'][0]).not_to eq structure['@id']
+
+        sub_range = result['structures'].last
+        expect(sub_range['ranges']).to be_blank
+        expect(sub_range['canvases'].length).to eq 1
+      end
     end
 
     context 'where there is a no sequence_rendering method' do

spec/spec_helper.rb

@@ -1,2 +1,3 @@
 $LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)
 require 'iiif_manifest'
+require 'pry'