#LD4L::OreRDF

LD4L ORE RDF provides tools for modeling list triples based on the ORE ontology and persisting to a triplestore.

Installation

Temporary get the gem from github until the gem is released publicly.

Add this line to your application's Gemfile:

gem 'ld4l-ore_rdf'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install ld4l-ore_rdf

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/ore_rdf'

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

# configure the solr url
ActiveTriples::Solrizer.configure do |config|
  config.solr_uri = "http://localhost:8983/solr/#/~cores/active_triples"
end


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

Example creating an aggregation with items individually.

agg10 = LD4L::OreRDF::CreateAggregation.call( :id=>'agg10', :title=>'My Resources', :description=>'Resources that I like', :owner=>p )

LD4L::OreRDF::AddAggregatedResource.call( agg10,'http://exmple.org/resource_1')
LD4L::OreRDF::AddAggregatedResource.call( agg10,'http://exmple.org/resource_2')
LD4L::OreRDF::AddAggregatedResource.call( agg10,'http://exmple.org/resource_3')

LD4L::OreRDF::PersistAggregation.call(agg10)

# To resume the aggregation at a later time, use...
agg = LD4L::OreRDF::ResumeAggregation.call( 'agg10' )

Example triples created for an aggregation.

puts agg.dump :ttl

<http://localhost/agg10> a <http://www.openarchives.org/ore/terms/Aggregation>;
   <http://purl.org/dc/terms/title> "My Resources";
   <http://purl.org/dc/terms/creator> <http://localhost/p4>;
   <http://purl.org/dc/terms/description> "Resources that I like";
   <http://www.iana.org/assignments/relation/first> <http://localhost/pxeff9a617-ab30-4d7e-971f-825032a597b0>;
   <http://www.iana.org/assignments/relation/last> <http://localhost/pxd6577d16-7565-46c7-8b0f-31e7816b0e57>;
   <http://www.openarchives.org/ore/terms/aggregates> "http://exmple.org/resource_1",
     "http://exmple.org/resource_2",
     "http://exmple.org/resource_3" .

Example triples created for each proxy in the list.

puts agg.first_proxy.first.dump :ttl

<http://localhost/pxeff9a617-ab30-4d7e-971f-825032a597b0> a <http://www.openarchives.org/ore/terms/Proxy>;
   <http://www.iana.org/assignments/relation/next> <http://localhost/px0f16c9de-7d97-406d-a81a-a501bc209f79>;
   <http://www.openarchives.org/ore/terms/proxyFor> "http://exmple.org/resource_1";
   <http://www.openarchives.org/ore/terms/proxyIn> <http://localhost/agg10> .
   
puts agg.first_proxy.first.next_proxy.first.dump :ttl

<http://localhost/px0f16c9de-7d97-406d-a81a-a501bc209f79> a <http://www.openarchives.org/ore/terms/Proxy>;
   <http://www.iana.org/assignments/relation/next> <http://localhost/pxd6577d16-7565-46c7-8b0f-31e7816b0e57>;
   <http://www.iana.org/assignments/relation/prev> <http://localhost/pxeff9a617-ab30-4d7e-971f-825032a597b0>;
   <http://www.openarchives.org/ore/terms/proxyFor> "http://exmple.org/resource_2";
   <http://www.openarchives.org/ore/terms/proxyIn> <http://localhost/agg10> .
   
puts agg.last_proxy.first.dump :ttl

<http://localhost/pxd6577d16-7565-46c7-8b0f-31e7816b0e57> a <http://www.openarchives.org/ore/terms/Proxy>;
   <http://www.iana.org/assignments/relation/prev> <http://localhost/px0f16c9de-7d97-406d-a81a-a501bc209f79>;
   <http://www.openarchives.org/ore/terms/proxyFor> "http://exmple.org/resource_3";
   <http://www.openarchives.org/ore/terms/proxyIn> <http://localhost/agg10> .

Example creating an aggregation with items in an array.

agg11 = LD4L::OreRDF::CreateAggregation.call( :id=>'agg11', :title=>'More Resources', :description=>'More resources that I like', :owner=>p )

resources = [ 'http://exmple.org/resource_5', 'http://exmple.org/resource_6', 'http://exmple.org/resource_7' ]
LD4L::OreRDF::AddAggregatedResources.call( agg11,resources)

LD4L::OreRDF::PersistAggregation.call(agg11)

# To resume the aggregation at a later time, use...
agg = LD4L::OreRDF::ResumeAggregation.call( 'agg11' )

Example triples created for an aggregation.

puts agg.dump :ttl

<http://localhost/agg11> a <http://www.openarchives.org/ore/terms/Aggregation>;
   <http://purl.org/dc/terms/title> "More Resources";
   <http://purl.org/dc/terms/creator> <http://localhost/p4>;
   <http://purl.org/dc/terms/description> "More resources that I like";
   <http://www.iana.org/assignments/relation/first> <http://localhost/pxcff53ec2-f406-422b-92e6-f603612c9856>;
   <http://www.iana.org/assignments/relation/last> <http://localhost/px4788758e-640b-455c-91f8-10f3c255a72d>;
   <http://www.openarchives.org/ore/terms/aggregates> 
     "http://exmple.org/resource_5",
     "http://exmple.org/resource_6",
     "http://exmple.org/resource_7" .

Example triples created for each proxy in the list.

puts agg.first_proxy.first.dump :ttl

<http://localhost/pxcff53ec2-f406-422b-92e6-f603612c9856> a <http://www.openarchives.org/ore/terms/Proxy>;
   <http://www.iana.org/assignments/relation/next> <http://localhost/pxf7cd384a-2727-4201-8ebe-22c35302b6c0>;
   <http://www.openarchives.org/ore/terms/proxyFor> "http://exmple.org/resource_5";
   <http://www.openarchives.org/ore/terms/proxyIn> <http://localhost/agg11> .

puts agg.first_proxy.first.next_proxy.first.dump :ttl

<http://localhost/pxf7cd384a-2727-4201-8ebe-22c35302b6c0> a <http://www.openarchives.org/ore/terms/Proxy>;
   <http://www.iana.org/assignments/relation/next> <http://localhost/px4788758e-640b-455c-91f8-10f3c255a72d>;
   <http://www.iana.org/assignments/relation/prev> <http://localhost/pxcff53ec2-f406-422b-92e6-f603612c9856>;
   <http://www.openarchives.org/ore/terms/proxyFor> "http://exmple.org/resource_6";
   <http://www.openarchives.org/ore/terms/proxyIn> <http://localhost/agg11> .
   
puts agg.last_proxy.first.dump :ttl

<http://localhost/px4788758e-640b-455c-91f8-10f3c255a72d> a <http://www.openarchives.org/ore/terms/Proxy>;
   <http://www.iana.org/assignments/relation/prev> <http://localhost/pxf7cd384a-2727-4201-8ebe-22c35302b6c0>;
   <http://www.openarchives.org/ore/terms/proxyFor> "http://exmple.org/resource_7";
   <http://www.openarchives.org/ore/terms/proxyIn> <http://localhost/agg11> .

Example: Find all aggregations

# Find all and return only the URIs for each aggregation
aggregation_uris = LD4L::OreRDF::FindAggregations.call

# Find all and return title and description
aggregation_properties = LD4L::OreRDF::FindAggregations.call(
    :properties => { :title => RDF::DC.title, :description => RDF::DC.description } )

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)

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::OreRDF.configure do |config|
  config.base_uri = "http://example.org/"
end

a = LD4L::OreRDF::AggregationResource.new(ActiveTriples::LocalName::Minter.generate_local_name(
              LD4L::OreRDF::AggregationResource, 10, {:prefix=>'ag'} ))

puts a.dump :ttl

NOTE: If base_uri is not used, you need to restart your interactive environment (e.g. irb, pry). Once the Aggregation 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 an aggregation with configured base_uri and default minter.

<http://example.org/ag45c9c85b-25af-4c52-96a4-cf0d8b70a768> a <http://www.openarchives.org/ore/terms/Aggregation> .

Example usage using configured base_uri and configured localname_minter.

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

a = LD4L::OreRDF::AggregationResource.new(ActiveTriples::LocalName::Minter.generate_local_name(
              LD4L::OreRDF::AggregationResource, 10, 'ag',
              &LD4L::OreRDF.configuration.localname_minter ))

puts a.dump :ttl

NOTE: If base_uri is not used, you need to restart your interactive environment (e.g. irb, pry). Once the Aggregation 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 an aggregation with configured base_uri and configured minter.

<http://example.org/ag_configured_6498ba05-8b21-4e8c-b9d4-a6d5d2180966> a <http://www.openarchives.org/ore/terms/Aggregation> .

Models

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

1. LD4L::OreRDF::AggregationResource - Implements the Aggregation class in the ORE ontology.
2. LD4L::OreRDF::ProxyResource - Implements the Proxy class in the ORE ontology.

Ontologies

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

• ORE
• FOAF
• RDF

Contributing

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