Rake task (needs to be included in the same Rakefile as fuseki_export.rb) to upload a single specified file from a backed up data folder.

single_file_upload.rb

task :upload_single_file do

  # database connections
  fuseki = FusekiConnection.new('glasgow-development', nil, nil, 3030)
  stardog = StardogConnection.new('glasgow-development')
  file = File.read("#{FusekiExport.template_app_root}/data_backup/postcodes.ttl")
  graph_uri_string = "http://linked.glasgow.gov.uk/graph/postcodes"

  # begin transaction with basic Stardog superuser creds
  begin_transaction_response = RestClient.post "http://#{stardog.username}:#{stardog.password}@localhost:#{stardog.port}/#{stardog.database_name}/transaction/begin", {:accept => :text}

  begin       

    transaction_token = begin_transaction_response.body
    puts "   Sending data to Stardog..."

    # submit data to Stardog endpoint
    stardog_graph_post_response = RestClient.post "http://#{stardog.username}:#{stardog.password}@localhost:#{stardog.port}/#{stardog.database_name}/#{transaction_token}/add?graph-uri=#{graph_uri_string}", file, {
        :content_type => 'text/turtle'
        }

    puts "   Posting data complete: #{stardog_graph_post_response.code}, ready to commit"

    # commit the transaction
    RestClient.post "http://#{stardog.username}:#{stardog.password}@localhost:#{stardog.port}/#{stardog.database_name}/transaction/commit/#{transaction_token}", {:accept => :text}

    puts "   Transaction complete for: #{graph_uri_string}" 

  rescue => transaction_exception

    # posting data to Stardog named graph has failed so we roll back the transaction

    begin
      RestClient.post "http://#{stardog.username}:#{stardog.password}@localhost:#{stardog.port}/#{stardog.database_name}/transaction/rollback/#{transaction_token}", {:accept => :text}
      puts "   Data could not be uploaded to Stardog. Transaction rolled back. Error: #{transaction_exception.to_s}"
    rescue => rollback_exception 
      puts "   Error: exception in transaction: #{transaction_exception}\n   Error: #{rollback_exception.to_s} - rollback failed"
    end

  end

end