Class: SPARQL::Client

Inherits:
Object show all
Defined in:
vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb,
vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client/query.rb,
vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client/update.rb,
vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client/version.rb,
vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client/repository.rb

Overview

A SPARQL 1.0/1.1 client for RDF.rb.

Defined Under Namespace

Modules: Update, VERSION Classes: ClientError, MalformedQuery, Query, QueryElement, Repository, ServerError

Constant Summary collapse

RESULT_JSON =
'application/sparql-results+json'.freeze
RESULT_XML =
'application/sparql-results+xml'.freeze
RESULT_CSV =
'text/csv'.freeze
RESULT_TSV =
'text/tab-separated-values'.freeze
RESULT_BOOL =

Sesame-specific

'text/boolean'.freeze
RESULT_BRTR =

Sesame-specific

'application/x-binary-rdf-results-table'.freeze
RESULT_ALL =
[
  RESULT_JSON,
  RESULT_XML,
  RESULT_BOOL,
  "#{RESULT_TSV};q=0.8",
  "#{RESULT_CSV};q=0.2",
  '*/*;q=0.1'
].join(', ').freeze
GRAPH_ALL =
(
  RDF::Format.content_types.keys +
  ['*/*;q=0.1']
).join(', ').freeze
ACCEPT_JSON =
{'Accept' => RESULT_JSON}.freeze
ACCEPT_XML =
{'Accept' => RESULT_XML}.freeze
ACCEPT_CSV =
{'Accept' => RESULT_CSV}.freeze
ACCEPT_TSV =
{'Accept' => RESULT_TSV}.freeze
ACCEPT_BRTR =
{'Accept' => RESULT_BRTR}.freeze
ACCEPT_RESULTS =
{'Accept' => RESULT_ALL}.freeze
ACCEPT_GRAPH =
{'Accept' => GRAPH_ALL}.freeze
DEFAULT_PROTOCOL =
1.0
DEFAULT_METHOD =
:post
XMLNS =
{'sparql' => 'http://www.w3.org/2005/sparql-results#'}.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(url, **options, &block) ⇒ Client

Initialize a new sparql client, either using the URL of a SPARQL endpoint or an RDF::Queryable instance to use the native SPARQL gem.

Parameters:

Options Hash (**options):

  • :method (Symbol) — default: DEFAULT_METHOD
  • :protocol (Number) — default: DEFAULT_PROTOCOL
  • :headers (Hash)

    HTTP Request headers

    Defaults Accept header based on available reader content types if triples are expected and to SPARQL result types otherwise, to allow for content negotiation based on available readers.

    Defaults User-Agent header, unless one is specified.

  • :read_timeout (Hash)


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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 95

def initialize(url, **options, &block)
  case url
  when RDF::Queryable
    @url, @options = url, options.dup
  else
    @url, @options = RDF::URI.new(url.to_s), options.dup
    @headers = @options.delete(:headers) || {}
    @http = http_klass(@url.scheme)

    # Close the http connection when object is deallocated
    ObjectSpace.define_finalizer(self, self.class.finalize(@http))
  end

  if block_given?
    case block.arity
      when 1 then block.call(self)
      else instance_eval(&block)
    end
  end
end

Instance Attribute Details

#headersHash{String => String} (readonly)

The HTTP headers that will be sent in requests to the endpoint.

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 70

def headers
  @headers
end

#optionsHash{Symbol => Object} (readonly)

Any miscellaneous configuration.

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 76

def options
  @options
end

#urlRDF::URI, RDF::Queryable (readonly)

The SPARQL endpoint URL, or an RDF::Queryable instance, to use the native SPARQL engine.

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 64

def url
  @url
end

Class Method Details

.finalize(klass) ⇒ Object

Close the http connection when object is deallocated



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 117

def self.finalize(klass)
  proc do
    if klass.respond_to?(:shutdown)
      begin
        # Attempt asynchronous shutdown
        Thread.new {klass.shutdown}
      rescue ThreadError
        klass.shutdown
      end
    end
  end
end

.parse_csv_bindings(csv, nodes = {}) ⇒ <RDF::Query::Solutions>



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 471

def self.parse_csv_bindings(csv, nodes = {})
  require 'csv' unless defined?(::CSV)
  csv = CSV.parse(csv.to_s) unless csv.is_a?(Array)
  vars = csv.shift
  solutions = RDF::Query::Solutions.new
  csv.each do |row|
    solution = RDF::Query::Solution.new
    row.each_with_index do |v, i|
      term = case v
      when /^_:(.*)$/ then nodes[$1] ||= RDF::Node($1)
      when /^\w+:.*$/ then RDF::URI(v)
      else RDF::Literal(v)
      end
      solution[vars[i].to_sym] = term
    end
    solutions << solution
  end
  solutions
end

.parse_json_bindings(json, nodes = {}) ⇒ <RDF::Query::Solutions>



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 420

def self.parse_json_bindings(json, nodes = {})
  require 'json' unless defined?(::JSON)
  json = JSON.parse(json.to_s) unless json.is_a?(Hash)
  case
    when json.has_key?('boolean')
      json['boolean']
    when json.has_key?('results')
      solutions = json['results']['bindings'].map do |row|
        row = row.inject({}) do |cols, (name, value)|
          cols.merge(name.to_sym => parse_json_value(value, nodes))
        end
        RDF::Query::Solution.new(row)
      end
      solns = RDF::Query::Solutions.new(solutions)

      # Set variable names explicitly
      if json.fetch('head', {}).has_key?('vars')
        solns.variable_names = json['head']['vars'].map(&:to_sym)
      end
      solns
  end
end

.parse_json_value(value, nodes = {}) ⇒ RDF::Value



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 448

def self.parse_json_value(value, nodes = {})
  case value['type'].to_sym
    when :bnode
      nodes[id = value['value']] ||= RDF::Node.new(id)
    when :uri
      RDF::URI.new(value['value'])
    when :literal
      RDF::Literal.new(value['value'], datatype: value['datatype'], language: value['xml:lang'])
    when :'typed-literal'
      RDF::Literal.new(value['value'], datatype: value['datatype'])
    when :triple
      s = parse_json_value(value['value']['subject'], nodes)
      p = parse_json_value(value['value']['predicate'], nodes)
      o = parse_json_value(value['value']['object'], nodes)
      RDF::Statement(s, p, o)
    else nil
  end
end

.parse_tsv_bindings(tsv, nodes = {}) ⇒ <RDF::Query::Solutions>



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 495

def self.parse_tsv_bindings(tsv, nodes = {})
  tsv = tsv.lines.map {|l| l.chomp.split("\t")} unless tsv.is_a?(Array)
  vars = tsv.shift.map {|h| h.sub(/^\?/, '')}
  solutions = RDF::Query::Solutions.new
  tsv.each do |row|
    # Flesh out columns which may be missing
    vars.each_with_index do |_, i|
      row[i] ||= ""
    end
    solution = RDF::Query::Solution.new
    row.each_with_index do |v, i|
      term = case v
      when ""                           then RDF::Literal("")
      when /^\d+\.\d*[eE][+-]?[0-9]+$/  then RDF::Literal::Double.new(v)
      when /^\d*\.\d+[eE][+-]?[0-9]+$/  then RDF::Literal::Double.new(v)
      when /^\d*\.\d+$/                 then RDF::Literal::Decimal.new(v)
      when /^\d+$/                      then RDF::Literal::Integer.new(v)
      else
        RDF::NTriples.unserialize(v) || RDF::Literal(v)
      end
      nodes[term.id] = term if term.is_a? RDF::Node
      solution[vars[i].to_sym] = term
    end
    solutions << solution
  end
  solutions
end

.parse_xml_bindings(xml, nodes = {}, library: :nokogiri) ⇒ <RDF::Query::Solutions>

Parameters:

Returns:

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 529

def self.parse_xml_bindings(xml, nodes = {}, library: :nokogiri)
  xml.force_encoding(::Encoding::UTF_8) if xml.respond_to?(:force_encoding)

  if defined?(::Nokogiri) && library == :nokogiri
    xml = Nokogiri::XML(xml).root unless xml.is_a?(Nokogiri::XML::Document)
    case
    when boolean = xml.xpath("//sparql:boolean", XMLNS)[0]
      boolean.text == 'true'
    when results = xml.xpath("//sparql:results", XMLNS)[0]
      solutions = results.elements.map do |result|
        row = {}
        result.elements.each do |binding|
          name  = binding.attr('name').to_sym
          value = binding.elements.first
          row[name] = parse_xml_value(value, nodes) if value
        end
        RDF::Query::Solution.new(row)
      end
      solns = RDF::Query::Solutions.new(solutions)

      # Set variable names explicitly
      var_names = xml.xpath("//sparql:head/sparql:variable/@name", XMLNS)
      solns.variable_names = var_names.map(&:to_s)
      solns
    end
  else
    # REXML
    xml = REXML::Document.new(xml).root unless xml.is_a?(REXML::Element)
    case
    when boolean = xml.elements['boolean']
      boolean.text == 'true'
    when results = xml.elements['results']
      solutions = results.elements.map do |result|
        row = {}
        result.elements.each do |binding|
          name  = binding.attributes['name'].to_sym
          value = binding.select { |node| node.kind_of?(::REXML::Element) }.first
          row[name] = parse_xml_value(value, nodes) if value
        end
        RDF::Query::Solution.new(row)
      end
      solns = RDF::Query::Solutions.new(solutions)

      # Set variable names explicitly
      var_names = xml.elements['head'].elements.map {|e| e.attributes['name']}
      solns.variable_names = var_names.map(&:to_sym)
      solns
    end
  end
end

.parse_xml_value(value, nodes = {}) ⇒ RDF::Value



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 584

def self.parse_xml_value(value, nodes = {})
  case value.name.to_sym
    when :bnode
      nodes[id = value.text] ||= RDF::Node.new(id)
    when :uri
      RDF::URI.new(value.text)
    when :literal
      lang     = value.respond_to?(:attr) ? value.attr('xml:lang') : value.attributes['xml:lang']
      datatype = value.respond_to?(:attr) ? value.attr('datatype') : value.attributes['datatype']
      RDF::Literal.new(value.text, language: lang, datatype: datatype)
    when :triple
      # Note, this is order dependent
      res = value.elements.map {|e| e.elements.to_a}.
        flatten.map {|e| parse_xml_value(e, nodes)}
      RDF::Statement(*res)
    else nil
  end
end

Instance Method Details

#ask(*args, **options) ⇒ Query

Executes a boolean ASK query.

Parameters:

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 145

def ask(*args, **options)
  call_query_method(:ask, *args, **options)
end

#clear(what, *arguments) #clear(what, *arguments, **options)

Executes a CLEAR operation.

This requires that the endpoint support SPARQL 1.1 Update.

Examples:

CLEAR GRAPH <http://example.org/>

client.clear(:graph, RDF::URI("http://example.org/"))

CLEAR DEFAULT

client.clear(:default)

CLEAR NAMED

client.clear(:named)

CLEAR ALL

client.clear(:all)

Overloads:

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 292

def clear(what, *arguments)
  self.update(Update::Clear.new(what, *arguments))
end

#clear_graph(graph_uri, **options)

This method returns an undefined value.

Executes a CLEAR GRAPH operation.

This is a convenience wrapper for the #clear method.

Examples:

CLEAR GRAPH <http://example.org/>

client.clear_graph("http://example.org/")

Parameters:

Options Hash (**options):

  • :silent (Boolean)

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 257

def clear_graph(graph_uri, **options)
  self.clear(:graph, graph_uri, **options)
end

#close

This method returns an undefined value.

Closes a client instance by finishing the connection. The client is unavailable for any further data operations; an IOError is raised if such an attempt is made. I/O streams are automatically closed when they are claimed by the garbage collector.



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 134

def close
  @http.shutdown if @http
  @http = nil
  self
end

#construct(*args, **options) ⇒ Query

Executes a graph CONSTRUCT query.

Parameters:

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 172

def construct(*args, **options)
  call_query_method(:construct, *args, **options)
end

#delete_data(data, **options)

This method returns an undefined value.

Executes a DELETE DATA operation.

This requires that the endpoint support SPARQL 1.1 Update.

Examples:

Deleting data sourced from a file or URL

data = RDF::Graph.load("https://raw.githubusercontent.com/ruby-rdf/rdf/develop/etc/doap.nt")
client.delete_data(data)

Deleting data from a named graph

client.delete_data(data, graph: "http://example.org/")

Parameters:

Options Hash (**options):

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 224

def delete_data(data, **options)
  self.update(Update::DeleteData.new(data, **options))
end

#delete_insert(delete_graph, insert_graph = nil, where_graph = nil, **options)

This method returns an undefined value.

Executes a DELETE/INSERT operation.

This requires that the endpoint support SPARQL 1.1 Update.

Parameters:

Options Hash (**options):

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 240

def delete_insert(delete_graph, insert_graph = nil, where_graph = nil, **options)
  self.update(Update::DeleteInsert.new(delete_graph, insert_graph, where_graph, **options))
end

#describe(*args, **options) ⇒ Query

Executes a DESCRIBE query.

Parameters:

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 163

def describe(*args, **options)
  call_query_method(:describe, *args, **options)
end

#http_klass(scheme) ⇒ Net::HTTP::Proxy (protected)

Returns an HTTP class or HTTP proxy class based on the http_proxy and https_proxy environment variables.

Parameters:

Returns:

  • (Net::HTTP::Proxy)


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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 717

def http_klass(scheme)
  proxy_url = nil
  case scheme
    when 'http'
      value = ENV['http_proxy']
      proxy_url = URI.parse(value) unless value.nil? || value.empty?
    when 'https'
      value = ENV['https_proxy']
      proxy_url = URI.parse(value) unless value.nil? || value.empty?
  end
  klass = Net::HTTP::Persistent.new(name: self.class.to_s, proxy: proxy_url)
  klass.keep_alive =  @options[:keep_alive] || 120
  klass.read_timeout = @options[:read_timeout] || 60
  klass
end

#insert_data(data, **options)

This method returns an undefined value.

Executes an INSERT DATA operation.

This requires that the endpoint support SPARQL 1.1 Update.

Note that for inserting non-trivial amounts of data, you probably ought to consider using the RDF store's native bulk-loading facilities or APIs, as INSERT DATA operations entail comparably higher parsing overhead.

Examples:

Inserting data constructed ad-hoc

client.insert_data(RDF::Graph.new { |graph|
  graph << [:jhacker, RDF::Vocab::FOAF.name, "J. Random Hacker"]
})

Inserting data sourced from a file or URL

data = RDF::Graph.load("https://raw.githubusercontent.com/ruby-rdf/rdf/develop/etc/doap.nt")
client.insert_data(data)

Inserting data into a named graph

client.insert_data(data, graph: "http://example.org/")

Parameters:

Options Hash (**options):

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 203

def insert_data(data, **options)
  self.update(Update::InsertData.new(data, **options))
end

#inspectString

Returns a developer-friendly representation of this object.

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 705

def inspect
  sprintf("#<%s:%#0x(%s)>", self.class.name, __id__, url.to_s)
end

#inspect!

This method returns an undefined value.

Outputs a developer-friendly representation of this object to stderr.



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 697

def inspect!
  warn(inspect)
end

#make_get_request(query, headers = {}) ⇒ Net::HTTPRequest (protected)

Constructs an HTTP GET request according to the SPARQL Protocol.

Parameters:

Returns:

  • (Net::HTTPRequest)

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 796

def make_get_request(query, headers = {})
  url = self.url.dup
  url.query_values = (url.query_values || {}).merge(query: query.to_s)
  set_url_default_graph url unless @options[:graph].nil?
  request = Net::HTTP::Get.new(url.request_uri, self.headers.merge(headers))
  request
end

#make_post_request(query, headers = {}) ⇒ Net::HTTPRequest (protected)

Constructs an HTTP POST request according to the SPARQL Protocol.

Parameters:

Returns:

  • (Net::HTTPRequest)

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 812

def make_post_request(query, headers = {})
  if @alt_endpoint.nil?
    url = self.url.dup
    set_url_default_graph url unless @options[:graph].nil?
    endpoint = url.request_uri
  else
    endpoint = @alt_endpoint
  end

  request = Net::HTTP::Post.new(endpoint, self.headers.merge(headers))
  case (self.options[:protocol] || DEFAULT_PROTOCOL).to_s
    when '1.1'
      request['Content-Type'] = 'application/sparql-' + (@op || :query).to_s
      request.body = query.to_s
    when '1.0'
      form_data = {(@op || :query) => query.to_s}
      form_data.merge!(
        {:'default-graph-uri' => @options[:graph]}
      ) if !@options[:graph].nil? && (@op.eql? :query)
      form_data.merge!(
        {:'using-graph-uri' => @options[:graph]}
      ) if !@options[:graph].nil? && (@op.eql? :update)
      request.set_form_data(form_data)
    else
      raise ArgumentError, "unknown SPARQL protocol version: #{self.options[:protocol].inspect}"
  end
  request
end

#parse_rdf_serialization(response, **options) ⇒ RDF::Enumerable

Parameters:

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 607

def parse_rdf_serialization(response, **options)
  options = {content_type: response.content_type} unless options[:content_type]
  if reader = RDF::Reader.for(**options)
    reader.new(response.body)
  else
    raise RDF::ReaderError, "no RDF reader was found for #{options}."
  end
end

#parse_response(response, **options) ⇒ Object

Parameters:

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 397

def parse_response(response, **options)
  case options[:content_type] || response.content_type
    when NilClass
      response.body
    when RESULT_BOOL # Sesame-specific
      response.body == 'true'
    when RESULT_JSON
      self.class.parse_json_bindings(response.body, nodes)
    when RESULT_XML
      self.class.parse_xml_bindings(response.body, nodes)
    when RESULT_CSV
      self.class.parse_csv_bindings(response.body, nodes)
    when RESULT_TSV
      self.class.parse_tsv_bindings(response.body, nodes)
    else
      parse_rdf_serialization(response, **options)
  end
end

#query(query, **options) ⇒ Array<RDF::Query::Solution>

Executes a SPARQL query and returns the parsed results.

Parameters:

Options Hash (**options):

Returns:

Raises:

  • (IOError)

    if connection is closed

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 325

def query(query, **options)
  @op = :query
  @alt_endpoint = options[:endpoint]
  case @url
  when RDF::Queryable
    require 'sparql' unless defined?(::SPARQL::Grammar)
    begin
      SPARQL.execute(query, @url, optimize: true, **options)
    rescue SPARQL::MalformedQuery
      $stderr.puts "error running #{query}: #{$!}"
      raise
    end
  else
    parse_response(response(query, **options), **options)
  end
end

#request(query, headers = {}) {|response| ... } ⇒ Net::HTTPResponse (protected)

Yields:

Yield Parameters:

  • response (Net::HTTPResponse)

Returns:

  • (Net::HTTPResponse)

Raises:

  • (IOError)

    if connection is closed

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 748

def request(query, headers = {}, &block)
  # Make sure an appropriate Accept header is present
  headers['Accept'] ||= if (query.respond_to?(:expects_statements?) ?
                            query.expects_statements? :
                            (query =~ /CONSTRUCT|DESCRIBE|DELETE|CLEAR/))
    GRAPH_ALL
  else
    RESULT_ALL
  end
  headers['User-Agent'] ||= "Ruby SPARQL::Client/#{SPARQL::Client::VERSION}"

  request = send("make_#{request_method(query)}_request", query, headers)

  request.basic_auth(url.user, url.password) if url.user && !url.user.empty?

  pre_http_hook(request) if respond_to?(:pre_http_hook)

  raise IOError, "Client has been closed" unless @http
  response = @http.request(::URI.parse(url.to_s), request)

  post_http_hook(response) if respond_to?(:post_http_hook)

  10.times do
    if response.kind_of? Net::HTTPRedirection
      response = @http.request(::URI.parse(response['location']), request)
    else
      return block_given? ? block.call(response) : response
    end
  end
  raise ServerError, "Infinite redirect at #{url}. Redirected more than 10 times."
end

#request_method(query) ⇒ Object (protected)

Return the HTTP verb for posting this request. this is useful if you need to override the HTTP verb based on the request being made. (e.g. Marmotta 3.3.0 requires GET for DELETE requests, but can accept POST for INSERT)



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 784

def request_method(query)
  (options[:method] || DEFAULT_METHOD).to_sym
end

#response(query, **options) ⇒ String

Executes a SPARQL query and returns the Net::HTTP::Response of the result.

Parameters:

Options Hash (**options):

Returns:

Raises:

  • (IOError)

    if connection is closed



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 376

def response(query, **options)
  headers = options[:headers] || @headers
  headers['Accept'] = options[:content_type] if options[:content_type]
  request(query, headers) do |response|
    case response
      when Net::HTTPBadRequest  # 400 Bad Request
        raise MalformedQuery.new(response.body + " Processing query #{query}")
      when Net::HTTPClientError # 4xx
        raise ClientError.new(response.body + " Processing query #{query}")
      when Net::HTTPServerError # 5xx
        raise ServerError.new(response.body + " Processing query #{query}")
      when Net::HTTPSuccess     # 2xx
        response
    end
  end
end

#select(*args, **options) ⇒ Query

Executes a tuple SELECT query.

Parameters:

Returns:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 154

def select(*args, **options)
  call_query_method(:select, *args, **options)
end

#set_url_default_graph(url) ⇒ Object (protected)

Setup url query parameter to use a specified default graph



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 846

def set_url_default_graph url
  if @options[:graph].is_a? Array
    graphs = @options[:graph].map {|graph|
      CGI::escape(graph)
    }
  else
    graphs = CGI::escape(@options[:graph])
  end
  case @op
  when :query
    url.query_values = (url.query_values || {})
      .merge(:'default-graph-uri' => graphs)
  when :update
    url.query_values = (url.query_values || {})
      .merge(:'using-graph-uri' => graphs)
  end
end

#update(query, **options)

This method returns an undefined value.

Executes a SPARQL update operation.

Parameters:

Options Hash (**options):

Raises:

  • (IOError)

    if connection is closed

See Also:



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# File 'vendor/bundler/ruby/3.1.0/bundler/gems/sparql-client-9e3f86b0f304/lib/sparql/client.rb', line 353

def update(query, **options)
  @op = :update
  @alt_endpoint = options[:endpoint]
  case @url
  when RDF::Queryable
    require 'sparql' unless defined?(::SPARQL::Grammar)
    SPARQL.execute(query, @url, update: true, optimize: true, **options)
  else
    response(query, **options)
  end
  self
end