Contents

# require 'active_rdf'
require 'queryengine/query2sparql'

# Generic superclass of all adapters

class ActiveRdfAdapter
  # indicate if adapter can read and write
  bool_accessor :reads, :writes, :enabled

  def initialize
    @enabled = true
  end

  # Indicate if the adapter supports contexts
  def supports_context?
    self.class.supports_context?
  end

  # translate a query to its string representation
  def translate(query)
    Query2SPARQL.translate(query)
  end

  # Clear the adapter. Crude default implementation, which can be overwritten
  # in subclasses. TODO: This queries all adapters, this may lead to problems...
  def clear
    raise(ActiveRdfError, "Can only delete from writing adapters") unless(writes?)
    to_delete = Query.new.select(:s, :p, :o).where(:s, :p, :o).execute
    to_delete.each do |s, p, o|
      delete(s, p, o)
    end
  end

  # Indicates if this adapter class supports contexts  
  def self.supports_context?
    @context_supported = false if(@context_supported == nil)
    @context_supported
  end

  private

  # Method to set the "context_supported" flag
  def self.supports_context
    @context_supported = true
  end

end

Version data entries

6 entries across 6 versions & 1 rubygems

Version	Path
activerdf_net7-1.6.16	lib/active_rdf/federation/active_rdf_adapter.rb
activerdf_net7-1.6.15	lib/active_rdf/federation/active_rdf_adapter.rb
activerdf_net7-1.6.14	lib/active_rdf/federation/active_rdf_adapter.rb
activerdf_net7-1.6.13	lib/active_rdf/federation/active_rdf_adapter.rb
activerdf_net7-1.6.12	lib/active_rdf/federation/active_rdf_adapter.rb
activerdf_net7-1.6.11	lib/active_rdf/federation/active_rdf_adapter.rb