ActiveTriples::LocalName

Provides utilities for working with local names under the ActiveTriples framework. Includes a default implementation of a local name minter.

Installation

Add this line to your application's Gemfile:

gem 'active_triples-local_name'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install active_triples-local_name

Usage

Utilities

• Local Name Minter
• Others may be added in the future.

Local Name Minter

Common prep code for all examples:

require 'active_triples'
require 'active_triples/local_name'

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

# create a DummyResource for ad-hoc testing
# NOTE: local name minter requires resource class to have base_uri configured
class DummyResourceWithBaseURI < ActiveTriples::Resource
  configure :base_uri => "http://example.org",
            :type => RDF::URI("http://example.org/SomeClass"),
            :repository => :default
end

Example: Using default minter

# create a new resource with a minted local name using default minter
localname = ActiveTriples::LocalName::Minter.generate_local_name(
              DummyResourceWithBaseURI, 10, {:prefix=>'d'})
# => something like -- "http://example.org/d59beebc5-5238-4aad-bf92-f63fbbd8faaa"

Parameter NOTES:

• for_class = DummyResourceWithBaseURI - resource class must have base_uri configured
• max_tries = 10 - If using default minter, it should easily find an available local name in 10 tries. If your minter algorithm gets lots of clashes with existing URIs and max_tries is set high, you may run into performance issues.
• minter_args (optional) = {:prefix=>'d'} - The default minter takes a single hash argument. You can define minters that take no arguments, multiple arguments, or a multiple item hash argument.
• minter_block = nil - When minter_block is not passed in, the default minter algorithm, which produces a UUID, will be used. Best practice is to start local names with an alpha character. UUIDs generate with either an alpha or numeric as the first character. Passing in a prefix of 'd' forces the local name to start with the character 'd'.

Example: Passing in a block as minter

# create a new resource with a minted local name using passed in block
localname = ActiveTriples::LocalName::Minter.generate_local_name(
              DummyResourceWithBaseURI,10,'d') do |prefix|
                prefix ||= ""
                local_name = SecureRandom.uuid
                local_name = prefix + "_blockproc_" + local_name if prefix && prefix.is_a?(String)
                local_name
              end
# => something like -- "http://example.org/d_blockproc_59beebc5-5238-4aad-bf92-f63fbbd8faaa"

Example: Passing in a method as minter

# minter method
def uuid_minter( *options )
  prefix = options[0][:prefix] if ! options.empty? && options[0].is_a?(Hash) && options[0].key?(:prefix)
  local_name = SecureRandom.uuid
  local_name = prefix + "_method_" + local_name if prefix && prefix.is_a?(String)
  local_name
end

# create a new resource with a minted local name using a minter method
localname = ActiveTriples::LocalName::Minter.generate_local_name(
              DummyResourceWithBaseURI,10,{:prefix=>"d"}) {|args| uuid_minter(args)}
# => something like -- "http://example.org/d_method_59beebc5-5238-4aad-bf92-f63fbbd8faaa"

Example: Override default minter.

# minter method
module ActiveTriples
  module LocalName
    class Minter
      def self.default_minter( *options )
        prefix = options[0][:prefix] if ! options.empty? && options[0].is_a?(Hash) && options[0].key?(:prefix)
        local_name = SecureRandom.uuid
        local_name = prefix + "_default_" + local_name if prefix && prefix.is_a?(String)
        local_name
      end
    end
  end
end

# create a new resource with a minted local name using override of default minter
localname = ActiveTriples::LocalName::Minter.generate_local_name(
              DummyResourceWithBaseURI,10,{:prefix=>"d"})
# => something like -- "http://example.org/d_default_59beebc5-5238-4aad-bf92-f63fbbd8faaa"

See more examples in spec/active_triples/local_name/minter_spec.rb.

Contributing

Please observe the following guidelines:

• Do your work in a feature branch based on master and rebase before submitting a pull request.
• Write tests for your contributions.
• Document every method you add using YARD annotations. (Note: Annotations are sparse in the existing codebase, help us fix that!)
• Organize your commits into logical units.
• Don't leave trailing whitespace (i.e. run git diff --check before committing).
• Use well formed commit messages.