Module: When::Events::DataSet::SparqlRepository

Defined in:

lib/when_exe/events.rb

Overview

外部 SPARQL サーバーを利用する場合に動作を置き換える

Instance Method Summary

• #event(uri, graph = nil) ⇒ Hash<String(GraphURI)=>RDF:Repository>

  指定の URI を主語とする Statement からなる RDF:Repository を生成する.

• #intersection_events(options) ⇒ Array<When::Events::Event>

  指定の条件を満たす Event の Array を返す.

Instance Method Details

#event(uri, graph = nil) ⇒ Hash<String(GraphURI)=>RDF:Repository>

指定の URI を主語とする Statement からなる RDF:Repository を生成する

Parameters:

• uri (String) —

  主語の URI

• graph (String) (defaults to: nil) —

  検索対象のグラフ

Returns:

• (Hash<String(GraphURI)=>RDF:Repository>) —

  生成した Repository の Hash

# File 'lib/when_exe/events.rb', line 909

def event(uri, graph=nil)
  rep     = Hash.new {|hash,key| hash[key] = ::RDF::Repository.new}
  subject = @resource[uri]

  # 問い合わせ文字列を準備する
  query_string  = "SELECT DISTINCT ?predicate ?object \n"
  query_string << "FROM <#{graph}> \n" if /./ =~ graph
  query_string << "WHERE { \n <#{uri}> ?predicate ?object . \n} \n"
# return query_string

  # 問い合わせを実行する
  client = ::SPARQL::Client.new(@endpoint)
  client.query(query_string).each do |solution|
    statement = ::RDF::Statement.new(subject, solution[:predicate], solution[:object])
    rep[''].insert(statement)
    rep[graph].insert(statement) if graph
  end
  rep
end

#intersection_events(options) ⇒ Array<When::Events::Event>

指定の条件を満たす Event の Array を返す

Parameters:

• options (Hash) —

  以下の通り

Options Hash (options):

• 'date' (String) —

  日付範囲

• 'contributor' (String) —

  情報提供者

• 'graph' (String) —

  グラフ

• 'group' (String) —

  グループ

• 'location' (String) —

  空間位置

• 'keyword' (String) —

  キーワード

• 'limit' (String or Integer) —

  最大取得数

• 'offset' (String or Integer) —

  取得開始レコード

• 'count' (Boolean) —

  イベント数のみの確認か?

Returns:

• (Array<When::Events::Event>) —

  Event の Array

# File 'lib/when_exe/events.rb', line 945

def intersection_events(options)

  # 問い合わせ文字列を準備する
  rdf_keys   = Hash.new {|hash,key| hash[key]=[]}
  role_keys  = @role.keys - [LABEL, REFERENCE, WHAT_DAY]
  role_keys.each do |role_key|
    @role[role_key][:target].scan(/<(.+?)>/) {rdf_keys[$1] << role_key}
  end
  keywords   = (/./ =~ options['keyword']) ? options['keyword'].split('*') : []
  loc_edges  = @order.key?(WEST) || @order.key?(SOUTH) || @order.key?(BOTTOM)
  triples    = []
  predicates = {}
  rdf_keys.each_pair do |rdf_key, role_key|
    if role_key.include?(SUBJECT)
      predicates['?s'] = rdf_key
    elsif role_key.include?(HAS_PART)
      keywords.each do |keyword|
        triples << "?s <#{rdf_key}> \"#{keyword}\" . "
      end
    elsif role_key.include?(CONTRIBUTOR) && /\A[^!]/ =~ options['contributor']
      triples << "?s <#{rdf_key}> \"#{options['contributor']}\" . "
    elsif role_key.include?(GROUP) && /./ =~ options['group']
      triples << "?s <#{rdf_key}> \"#{options['group']}\" . "
    elsif role_key.include?(SPATIAL) && /./ =~ options['location'] && !loc_edges
      triples << "?s <#{rdf_key}> \"#{options['location']}\" . "
    else
      object = "?o#{predicates.size}"
      predicates[object] = rdf_key
      triples << "?s <#{rdf_key}> #{object} . "
    end
  end
  select  = options['count'] ?
              "SELECT DISTINCT (COUNT(*) AS ?count) " :
              "SELECT DISTINCT #{predicates.keys.join(' ')} "
  filters = []
  filters.concat(range_filter(When.date_or_era(options['date']), predicates, rdf_keys, 'valid', options['date'])) if /./ =~ options['date']
  filters.concat(regex_filter(options['contributor'], predicates, rdf_keys, 'contributor'))
  if /./ =~ options['location'] && loc_edges
    location = When.where?(options['location'])
    filters.concat(range_filter(location.long, predicates, rdf_keys, 'longitude')) if @order.key?(WEST)
    filters.concat(range_filter(location.lat,  predicates, rdf_keys, 'latitude' )) if @order.key?(SOUTH)
    filters.concat(range_filter(location.alt,  predicates, rdf_keys, 'altitude' )) if @order.key?(BOTTOM)
  end
  query_string  = "#{select}\n"
  query_string << "FROM <#{options['graph']}> \n" if @role.key?(GRAPH) && /./ =~ options['graph']
  query_string << "WHERE { \n #{triples.map {|t| t+"\n "}.join('')}"
  query_string << " FILTER ( \n  #{filters.map {|f| ' '+f}.join(" && \n  ")}\n  ) \n" unless filters.empty?
  query_string << "} \n"
  query_string << "ORDER BY #{attr2var(@order.key?(START) ? 'start' : 'valid', predicates, rdf_keys)} \n" unless options['count']
  query_string << "LIMIT  #{options['limit']} \n"  if options['limit' ].to_i > 1
  query_string << "OFFSET #{options['offset']} \n" if options['offset'].to_i > 1
  return query_string if options['debug']

  # 問い合わせを実行する
  client = ::SPARQL::Client.new(@endpoint)
  if options['count']
    # イベント数のみ確認する
    client.query(query_string).each do |solution|
      return solution[:count].to_i
    end
    return 0

  else
    # イベントの内容を取り出す
    client.query(query_string).map {|solution|
      event = Hash[*predicates.keys.map {|predicate|
                object = solution[predicate[1..-1].to_sym]
                [predicates[predicate],
                 case object
                 when ::RDF::Literal::Integer ; object.to_i
                 when ::RDF::Literal::Numeric ; object.to_f
                 else object.to_s
                 end]
              }.flatten]
      rdf_keys.each_pair do |rdf_key, role_key|
        next if event.key?(rdf_key)
        if role_key.include?(HAS_PART)
          event[rdf_key] = keywords
        elsif role_key.include?(CONTRIBUTOR)
          event[rdf_key] = options['contributor']
        elsif role_key.include?(GRAPH)
          event[rdf_key] = (/./ =~ options['graph'] ? options['graph'] : @default_graph)
        elsif role_key.include?(SPATIAL)
          event[rdf_key] = options['location']
        end
      end
      uri = event[predicates['?s']]
      id  = uri[@default_graph.length..-1] if @default_graph && uri.index(@default_graph)
      Event.new(self, id || uri, event)
    }
  end
end