Class: SPARQL::Client::Repository

Inherits:
RDF::Repository
  • Object
show all
Defined in:
vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb

Overview

A read-only repository view of a SPARQL endpoint.

See Also:

  • `RDF`RDF::Repository`

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(uri: nil, **options, &block) ⇒ Repository

Returns a new instance of Repository

Parameters:

  • uri (URI, #to_s)

    Endpoint of this repository

  • options (Hash{Symbol => Object})

    passed to RDF::Repository

Raises:

  • (ArgumentError)


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 14

def initialize(uri: nil, **options, &block)
  raise ArgumentError, "uri is a required parameter" unless uri
  @options = options.merge(uri: uri)
  @update_client = SPARQL::Client.new(options.delete(:update_endpoint), options) if options[:update_endpoint]
  @client  = SPARQL::Client.new(uri, options)
  super(@options, &block)
end

Instance Attribute Details

#clientSPARQL::Client (readonly)

Returns:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 8

def client
  @client
end

Instance Method Details

#countInteger Also known as: size, length

Returns the number of statements in this repository.

Returns:

See Also:

  • RDF::Repository#count?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 176

def count
  begin
    binding = client.query("SELECT (COUNT(*) AS ?count) WHERE { ?s ?p ?o }").first.to_h
    binding[:count].value.to_i rescue 0
  rescue SPARQL::Client::MalformedQuery => e
    # SPARQL 1.0 does not include support for aggregate functions:
    count = 0
    each_statement { count += 1 } # TODO: optimize this
    count
  end
end

#delete(*statements) ⇒ self #delete(statements) ⇒ self

Deletes RDF statements from self. If any statement contains an RDF::Query::Variable, it is considered to be a pattern, and used to query self to find matching statements to delete.

Overloads:

  • #delete(*statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError)

      if self is immutable

  • #delete(statements) ⇒ self

    Parameters:

    Returns:

    • (self)

    Raises:

    • (TypeError)

      if self is immutable

See Also:

  • RDF::Mutable#delete


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 233

def delete(*statements)
  statements.map! do |value|
    if value.respond_to?(:each_statement)
      delete_statements(value)
      nil
    else
      value
    end
  end
  statements.compact!
  delete_statements(statements) unless statements.empty?
  return self
end

#delete_statements(statements) (protected)

This method returns an undefined value.

Deletes the given RDF statements from the underlying storage.

Overridden here to use SPARQL/UPDATE

Parameters:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 309

def delete_statements(statements)
  constant = statements.all? do |value|
    # needs to be flattened... urgh
    !value.respond_to?(:each_statement) && begin
      statement = RDF::Statement.from(value)
      statement.constant? && !statement.has_blank_nodes?
    end
  end

  if constant
    update_client.delete_data(statements)
  else
    update_client.delete_insert(statements)
  end
end

#each {|statement| ... } ⇒ Object

Enumerates each RDF statement in this repository.

Yields:

  • (statement)

Yield Parameters:

See Also:

  • RDF::Repository#each


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 36

def each(&block)
  client.construct([:s, :p, :o]).where([:s, :p, :o]).each_statement(&block)
end

#each_object {|object| ... } ⇒ Enumerator

Iterates over each object in this repository.

Yields:

  • (object)

Yield Parameters:

  • object (RDF::Value)

Returns:

  • (Enumerator)

See Also:

  • RDF::Repository#each_object?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 144

def each_object(&block)
  if block_given?
    client.select(:o, :distinct => true).where([:s, :p, :o]).each_solution { |solution| block.call(solution[:o]) }
  end
  enum_object
end

#each_predicate {|predicate| ... } ⇒ Enumerator

Iterates over each predicate in this repository.

Yields:

  • (predicate)

Yield Parameters:

Returns:

  • (Enumerator)

See Also:

  • RDF::Repository#each_predicate?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 130

def each_predicate(&block)
  if block_given?
    client.select(:p, :distinct => true).where([:s, :p, :o]).each_solution { |solution| block.call(solution[:p]) }
  end
  enum_predicate
end

#each_statement {|statement| ... } #each_statementEnumerator<RDF::Statement>

Iterates the given block for each RDF statement.

If no block was given, returns an enumerator.

The order in which statements are yielded is undefined.

Overloads:

  • #each_statement {|statement| ... }

    This method returns an undefined value.

    Yields:

    • (statement)

      each statement

    Yield Parameters:

    Yield Returns:

    • (void)

      ignored

  • #each_statementEnumerator<RDF::Statement>

    Returns:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 56

def each_statement(&block)
  if block_given?
    # Invoke {#each} in the containing class:
    each(&block)
  end
  enum_statement
end

#each_subject {|subject| ... } ⇒ Enumerator

Iterates over each subject in this repository.

Yields:

  • (subject)

Yield Parameters:

  • subject (RDF::Resource)

Returns:

  • (Enumerator)

See Also:

  • RDF::Repository#each_subject?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 116

def each_subject(&block)
  if block_given?
    client.select(:s, :distinct => true).where([:s, :p, :o]).each_solution { |solution| block.call(solution[:s]) }
  end
  enum_subject
end

#empty?Boolean

Returns true if this repository contains no statements.

Returns:

  • (Boolean)

See Also:

  • RDF::Repository#empty?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 196

def empty?
  client.ask.whether([:s, :p, :o]).false?
end

#has_object?(object) ⇒ Boolean

Returns true if this repository contains the given object.

Parameters:

  • object (RDF::Value)

Returns:

  • (Boolean)

See Also:

  • RDF::Repository#has_object?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 105

def has_object?(object)
  client.ask.whether([:s, :p, object]).true?
end

#has_predicate?(predicate) ⇒ Boolean

Returns true if this repository contains the given predicate.

Parameters:

Returns:

  • (Boolean)

See Also:

  • RDF::Repository#has_predicate?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 95

def has_predicate?(predicate)
  client.ask.whether([:s, predicate, :o]).true?
end

#has_statement?(statement) ⇒ Boolean

Returns true if this repository contains the given statement.

Parameters:

Returns:

  • (Boolean)

See Also:

  • RDF::Repository#has_statement?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 167

def has_statement?(statement)
  has_triple?(statement.to_triple)
end

#has_subject?(subject) ⇒ Boolean

Returns true if this repository contains the given subject.

Parameters:

  • subject (RDF::Resource)

Returns:

  • (Boolean)

See Also:

  • RDF::Repository#has_subject?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 85

def has_subject?(subject)
  client.ask.whether([subject, :p, :o]).true?
end

#has_triple?(triple) ⇒ Boolean

Returns true if this repository contains the given triple.

Parameters:

Returns:

  • (Boolean)

See Also:

  • RDF::Repository#has_triple?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 157

def has_triple?(triple)
  client.ask.whether(triple.to_a[0...3]).true?
end

#insert_statements(statements) (protected)

This method returns an undefined value.

Inserts the given RDF statements into the underlying storage or output stream.

Overridden here to use SPARQL/UPDATE

Parameters:

Raises:

  • (ArgumentError)

Since:

  • 0.1.6



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 334

def insert_statements(statements)
  raise ArgumentError, "Some statement is incomplete" if statements.any?(&:incomplete?)
  update_client.insert_data(statements)
end

#query_execute(query, options = {}) {|solution| ... } (protected)

This method returns an undefined value.

Queries self using the given basic graph pattern (BGP) query, yielding each matched solution to the given block.

Overrides Queryable::query_execute to use SPARQL::Client::query

Parameters:

  • query (RDF::Query)

    the query to execute

  • options (Hash{Symbol => Object}) (defaults to: {})

    ({}) Any other options passed to query.execute

Yields:

  • (solution)

Yield Parameters:

  • solution (RDF::Query::Solution)

Yield Returns:

  • (void)

    ignored

See Also:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 265

def query_execute(query, options = {}, &block)
  return nil unless block_given?
  q = SPARQL::Client::Query.select(query.variables).where(*query.patterns)
  client.query(q, options).each do |solution|
    yield solution
  end
end

#query_pattern(pattern, options = {}) {|statement| ... } ⇒ Enumerable<Statement> (protected)

TODO:

This should use basic SPARQL query mechanism.

Queries self for RDF statements matching the given pattern.

Examples:

repository.query([nil, RDF::DOAP.developer, nil])
repository.query(:predicate => RDF::DOAP.developer)

Parameters:

  • pattern (Pattern)

Yields:

  • (statement)

Yield Parameters:

  • (Statement)

Returns:

  • (Enumerable<Statement>)

See Also:

  • RDF::Queryable#query_pattern


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 287

def query_pattern(pattern, options = {}, &block)
  pattern = pattern.dup
  pattern.subject   ||= RDF::Query::Variable.new
  pattern.predicate ||= RDF::Query::Variable.new
  pattern.object    ||= RDF::Query::Variable.new
  pattern.initialize!
  query = client.construct(pattern).where(pattern)

  if block_given?
    query.each_statement(&block)
  else
    query.solutions.to_a.extend(RDF::Enumerable, RDF::Queryable)
  end
end

#update_clientSPARQL::Client

Returns the client for the update_endpoint if specified, otherwise the #client.

Returns:



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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 27

def update_client
  @update_client || @client
end

#writable?Boolean

Returns false to indicate that this is a read-only repository.

Returns:

  • (Boolean)

See Also:

  • RDF::Mutable#mutable?


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# File 'vendor/bundler/ruby/2.5.0/bundler/gems/sparql-client-204355edf946/lib/sparql/client/repository.rb', line 205

def writable?
  true
end