LD4L::OpenAnnotationRDF

LD4L Open Annotation RDF provides tools for modeling annotations based on the Open Annotation ontology and persisting to a triplestore.

Installation

Add this line to your application's Gemfile:

gem 'ld4l-open_annotation_rdf'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install ld4l-open_annotation_rdf

Primary Dependencies

Usage

Caveat: This gem is part of the LD4L Project and is being used in that context. There is no guarantee that the code will work in a usable way outside of its use in LD4L Use Cases.

Examples

Setup required for all examples.

require 'ld4l/open_annotation_rdf'

# create an in-memory repository
ActiveTriples::Repositories.add_repository :default, RDF::Repository.new

p = LD4L::FoafRDF::Person.new('p4')

Example creating a comment annotation.

ca = LD4L::OpenAnnotationRDF::CommentAnnotation.new('c10')
ca.hasTarget = RDF::URI("http://example.org/bibref/br3")
cb = ca.setComment("This book is a good resource on archery technique.")
ca.annotatedBy = p
ca.setAnnotatedAtNow
ca.persist!

puts ca.dump :ttl
puts cb.dump :ttl

Example triples created for a comment annotation.

<http://localhost/c10> a <http://www.w3.org/ns/oa#Annotation>;
   <http://www.w3.org/ns/oa#annotatedAt> "2014-11-26T15:53:49Z";
   <http://www.w3.org/ns/oa#annotatedBy> <http://localhost/p4>;
   <http://www.w3.org/ns/oa#hasBody> <http://localhost/9c8c8126-2d31-48be-81d8-3cd4748a3351>;
   <http://www.w3.org/ns/oa#hasTarget> <http://example.org/bibref/br3>;
   <http://www.w3.org/ns/oa#motivatedBy> <http://www.w3.org/ns/oa#commenting> .

<http://localhost/9c8c8126-2d31-48be-81d8-3cd4748a3351> a <http://www.w3.org/2011/content#ContentAsText>,
                                                          <http://purl.org/dc/dcmitype/Text>;
   <http://purl.org/dc/terms/format> "text/plain";
   <http://www.w3.org/2011/content#chars> "This book is a good resource on archery technique." .

Example creating a tag annotation.

ta = LD4L::OpenAnnotationRDF::TagAnnotation.new('t10')
ta.hasTarget = RDF::URI("http://example.org/bibref/br3")
tb = ta.setTag("archery")
ta.annotatedBy = p
ta.setAnnotatedAtNow
ta.persist!

puts ta.dump :ttl
puts tb.dump :ttl

Example triples created for a tag annotation.

<http://localhost/t10> a <http://www.w3.org/ns/oa#Annotation>;
   <http://www.w3.org/ns/oa#annotatedAt> "2014-11-26T15:56:32Z";
   <http://www.w3.org/ns/oa#annotatedBy> <http://localhost/p4>;
   <http://www.w3.org/ns/oa#hasBody> <http://localhost/88db4b38-8b99-4939-b376-1392019aa30c>;
   <http://www.w3.org/ns/oa#hasTarget> <http://example.org/bibref/br3>;
   <http://www.w3.org/ns/oa#motivatedBy> <http://www.w3.org/ns/oa#tagging> .

<http://localhost/88db4b38-8b99-4939-b376-1392019aa30c> a <http://www.w3.org/ns/oa#Tag>,
                                                          <http://www.w3.org/2011/content#ContentAsText>;
   <http://www.w3.org/2011/content#chars> "archery" .

Example creating a semantic tag annotation.

sta = LD4L::OpenAnnotationRDF::SemanticTagAnnotation.new('st10')
sta.hasTarget = RDF::URI("http://example.org/bibref/br3")
stb = sta.setTerm(RDF::URI("http://example.org/term/engineering"))
sta.annotatedBy = p
sta.setAnnotatedAtNow
sta.persist!

puts sta.dump :ttl
puts stb.dump :ttl

Example triples created for a semantic tag annotation.

<http://localhost/st10> a <http://www.w3.org/ns/oa#Annotation>;
   <http://www.w3.org/ns/oa#annotatedAt> "2014-11-26T15:59:01Z";
   <http://www.w3.org/ns/oa#annotatedBy> <http://localhost/p4>;
   <http://www.w3.org/ns/oa#hasBody> <http://example.org/term/engineering>;
   <http://www.w3.org/ns/oa#hasTarget> <http://example.org/bibref/br3>;
   <http://www.w3.org/ns/oa#motivatedBy> <http://www.w3.org/ns/oa#tagging> .

<http://example.org/term/engineering> a <http://www.w3.org/ns/oa#SemanticTag> .

Resume annotation of known type. This is the more efficient approach and should be used if the type of the annotation is known.

a1 = LD4L::OpenAnnotationRDF::CommentAnnotation.resume(RDF::URI('http://localhost/c10'))
# => #<LD4L::OpenAnnotationRDF::CommentAnnotation:0x3fdd8267adc8(default)>
comment = a1.getComment
# => "This book is a good resource on archery technique."

a2 = LD4L::OpenAnnotationRDF::TagAnnotation.resume(RDF::URI('http://localhost/t10'))
# => #<LD4L::OpenAnnotationRDF::TagAnnotation:0x3fdd826073f0(default)>
tag = a2.getTag
# => "archery"

a3 = LD4L::OpenAnnotationRDF::SemanticTagAnnotation.resume(RDF::URI('http://localhost/st10'))
# => #<LD4L::OpenAnnotationRDF::SemanticTagAnnotation:0x3fdd8259c7a8(default)>
term = a2.getTerm
# => #<RDF::URI:0x3fdbb4f37300 URI:http://example.org/term/engineering>

Resume annotation of unknown type.

## Using RDF::URI
# Create the annotations first using previous examples.
a1 = LD4L::OpenAnnotationRDF::Annotation.resume(RDF::URI('http://localhost/c10'))
# => #<LD4L::OpenAnnotationRDF::CommentAnnotation:0x3fdd8267adc8(default)>
comment = a1.getComment
# => "This book is a good resource on archery technique."

a2 = LD4L::OpenAnnotationRDF::Annotation.resume(RDF::URI('http://localhost/t10'))
# => #<LD4L::OpenAnnotationRDF::TagAnnotation:0x3fdd826073f0(default)>
tag = a2.getTag
# => "archery"

a3 = LD4L::OpenAnnotationRDF::Annotation.resume(RDF::URI('http://localhost/st10'))
# => #<LD4L::OpenAnnotationRDF::SemanticTagAnnotation:0x3fdd8259c7a8(default)>
term = a2.getTerm
# => #<RDF::URI:0x3fdbb4f37300 URI:http://example.org/term/engineering>


## Using string URI
# Create the annotations first using previous examples.
a1 = LD4L::OpenAnnotationRDF::Annotation.resume('http://localhost/c10')
# => #<LD4L::OpenAnnotationRDF::CommentAnnotation:0x3fdd8267adc8(default)>
# => #<LD4L::OpenAnnotationRDF::CommentAnnotation:0x3fdd8267adc8(default)>
comment = a1.getComment

a2 = LD4L::OpenAnnotationRDF::Annotation.resume('http://localhost/t10')
# => #<LD4L::OpenAnnotationRDF::TagAnnotation:0x3fdd826073f0(default)>
tag = a2.getTag
# => "archery"

a3 = LD4L::OpenAnnotationRDF::Annotation.resume('http://localhost/st10')
# => #<LD4L::OpenAnnotationRDF::SemanticTagAnnotation:0x3fdd8259c7a8(default)>
term = a2.getTerm
# => #<RDF::URI:0x3fdbb4f37300 URI:http://example.org/term/engineering>


## Using localname expanded using configured base_uri
# Create the annotations first using previous examples.
a1 = LD4L::OpenAnnotationRDF::Annotation.resume('c10')
# => #<LD4L::OpenAnnotationRDF::CommentAnnotation:0x3fdd8267adc8(default)>
comment = a1.getComment
# => "This book is a good resource on archery technique."

a2 = LD4L::OpenAnnotationRDF::Annotation.resume('t10')
# => #<LD4L::OpenAnnotationRDF::TagAnnotation:0x3fdd826073f0(default)>
tag = a2.getTag
# => "archery"

a3 = LD4L::OpenAnnotationRDF::Annotation.resume('st10')
# => #<LD4L::OpenAnnotationRDF::SemanticTagAnnotation:0x3fdd8259c7a8(default)>
term = a2.getTerm
# => #<RDF::URI:0x3fdbb4f37300 URI:http://example.org/term/engineering>

Configurations

base_uri - base URI used when new resources are created (default="http://localhost/")
localname_minter - minter function to use for creating unique local names (default=nil which uses default minter in active_triples-local_name gem)
unique_tags - if true, re-use existing TagBodies only creating a new TagBody if one doesn't exist with the tag value being set; otherwise, if false, create new TagBody when tag value is updated (default=true)

Setup for all examples.

Restart your interactive session (e.g. irb, pry).
Use the Setup for all examples in main Examples section above.

Example usage using configured base_uri and default localname_minter.

LD4L::OpenAnnotationRDF.reset
LD4L::OpenAnnotationRDF.configure do |config|
  config.base_uri = "http://example.org/"
end

ca = LD4L::OpenAnnotationRDF::CommentAnnotation.new(ActiveTriples::LocalName::Minter.generate_local_name(
              LD4L::OpenAnnotationRDF::CommentAnnotation, 10, {:prefix=>'ca'} ))

puts ca.dump :ttl

ca = LD4L::OpenAnnotationRDF::CommentAnnotation.new(ActiveTriples::LocalName::Minter.generate_local_name(
              LD4L::OpenAnnotationRDF::CommentAnnotation, 10, {:prefix=>'ca'},
              &LD4L::OpenAnnotationRDF.configuration.localname_minter ))

puts ca.dump :ttl

NOTE: If base_uri is not used, you need to restart your interactive environment (e.g. irb, pry). Once the CommentAnnotation class is instantiated the first time, the base_uri for the class is set. If you ran through the main Examples, the base_uri was set to the default base_uri.

Example triples created for a person with configured base_uri and default minter.

<http://example.org/ca45c9c85b-25af-4c52-96a4-cf0d8b70a768> a <http://www.w3.org/ns/oa#Annotation>;
   <http://www.w3.org/ns/oa#motivatedBy> <http://www.w3.org/ns/oa#commenting> .

Example usage using configured base_uri and configured localname_minter.

LD4L::OpenAnnotationRDF.configure do |config|
  config.base_uri = "http://example.org/"
  config.localname_minter = lambda { |prefix=""| prefix+'_configured_'+SecureRandom.uuid }
end

ca = LD4L::OpenAnnotationRDF::CommentAnnotation.new(ActiveTriples::LocalName::Minter.generate_local_name(
              LD4L::OpenAnnotationRDF::CommentAnnotation, 10, 'ca',
              &LD4L::OpenAnnotationRDF.configuration.localname_minter ))

puts ca.dump :ttl

Example triples created for a person with configured base_uri and configured minter.

<http://example.org/ca_configured_6498ba05-8b21-4e8c-b9d4-a6d5d2180966> a <http://www.w3.org/ns/oa#Annotation>;
   <http://www.w3.org/ns/oa#motivatedBy> <http://www.w3.org/ns/oa#commenting> .

Example configuring unique_tags

# Any of these are valid and will change the configuration of unique_tags
LD4L::OpenAnnotationRDF.configuration.unique_tags = true
LD4L::OpenAnnotationRDF.configuration.unique_tags = false
LD4L::OpenAnnotationRDF.configuration.reset_unique_tags

Models

The LD4L::OpenAnnotationRDF gem provides model definitions using the ActiveTriples framework extension of ruby-rdf/rdf. The following models are provided:

LD4L::OpenAnnotationRDF::Annotation - Implements an open annotation.
LD4L::OpenAnnotationRDF::CommentAnnotation - Extends Annotation to implement a comment annotation of free-form text.
LD4L::OpenAnnotationRDF::CommentBody - Implements a body holding free-form text.
LD4L::OpenAnnotationRDF::TagAnnotation - Extends Annotation to implement a tag annotation of user specified short phrase tag.
LD4L::OpenAnnotationRDF::TagBody - Implements a body holding the short phrase tag.
LD4L::OpenAnnotationRDF::SemanticTagAnnotation - Extends Annotation to implement a semantic tag annotation with values limited to a controlled vocabulary.
LD4L::OpenAnnotationRDF::SemanticTagBody - Implements a body with rdf_subject equal to the URI of the controlled vocabulary term .

Ontologies

The listed ontologies are used to represent the primary metadata about the annotations. Other ontologies may also be used that aren't listed.

Contributing

Fork it ( https://github.com/[my-github-username]/ld4l-open_annotation_rdf/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request