Redland::Parser

The Parser class for rdf. There are currently three types of parsers *'rdfxml'- a rdf parser *'ntriples' a An triples parser *'turtle' - a parser for the turtle syntax as defined in

http://www.dajobe.org/2004/01/turtle/

*'rss-tag-soup' - a parser for all RSS flavours and some atom *'grddl' - GRDDL

The last two may or may not be available depending on systems.

model = Model.new()
parser = Parser.ntriples()
parser.parse_into_model(model,'file:./ical.rdf')

Attributes

context[RW]

Public Class Methods

create_finalizer(parser) click to toggle source

# File rdf/redland/parser.rb, line 34
def Parser.create_finalizer(parser)
  proc {|id| # "Finalizer on #{id}"
    #$log_final.info "closing parser"
    Redland::librdf_free_parser(parser)
  }
end

new(name='rdfxml',mime_type="application/rdf+xml",uri=nil,context=nil) click to toggle source

create a new Parser. if no name is given, it defaults to parsing RDF/XML syntax

# File rdf/redland/parser.rb, line 25
def initialize(name='rdfxml',mime_type="application/rdf+xml",uri=nil,context=nil)
  @context = nil
  @idents = []
  uri=uri.uri if uri
  @parser = Redland.librdf_new_parser($world.world,name,mime_type,uri)
  raise RedlandError.new("Parser construction failed") if !@parser
  ObjectSpace.define_finalizer(self,Parser.create_finalizer(@parser))
end

ntriples(uri=nil) click to toggle source

create a parser for the ntriples syntax

# File rdf/redland/parser.rb, line 42
def Parser.ntriples(uri=nil)
  return Parser.new('ntriples',"",uri)
end

raptor(uri=nil) click to toggle source

create a parser for rdf syntax

# File rdf/redland/parser.rb, line 52
def Parser.raptor(uri=nil)
  return Parser.new('rdfxml','application/rdf+xml',uri)
end

turtle(uri=nil) click to toggle source

create a parser for the turtle syntax

# File rdf/redland/parser.rb, line 47
def Parser.turtle(uri=nil)
  return Parser.new('turtle',"",uri)
end

Public Instance Methods

add_ident(node) click to toggle source

# File rdf/redland/parser.rb, line 165
def add_ident(node)
  @idents << node
end

feature(uri) click to toggle source

Get a parser feature. The feature is a Uri

# File rdf/redland/parser.rb, line 147
def feature(uri)
  if uri.class == String then uri = Uri.new(uri) end
  value = Redland::librdf_parser_get_feature(@parser,uri.uri)
  if value == "NULL" or value == nil
    return nil
  else
    return Node.new(:from_object=>value)
  end
end

parse_as_stream(uri,base_uri=nil) click to toggle source

Parse the given uri with optional base_uri and return a Stream. If block_given, yield the Statement instead Returns nil on failure.

# File rdf/redland/parser.rb, line 59
def parse_as_stream(uri,base_uri=nil)
  if uri.class == String then uri = Uri.new(uri) end
  if base_uri.class == String then base_uri = Uri.new(base_uri) end
  unless base_uri
    my_stream = Redland::librdf_parser_parse_as_stream @parser, uri.uri, nil
  else
    my_stream = Redland::librdf_parser_parse_as_stream @parser, uri.uri ,base_uri.uri
  end
  return nil if !my_stream
  stream = Stream.new(my_stream,self)
  if !block_given?
    return stream
  else
    while not stream.end?
      yield stream.current
      stream.next
    end
  end
end

parse_into_model(model,uri,base_uri=nil,context=@context) click to toggle source

Parse the syntax at the uri Uri with optional base Uri base_uri into Model model. If the base_uri is given then the content is parsed as if it was at the base_uri rather than the uri. If the optional context is given, the statement is added to the context

NOTE: The order of the arguments to this method is different from the C API and other language bindings.

# File rdf/redland/parser.rb, line 85
def parse_into_model(model,uri,base_uri=nil,context=@context)
  #puts "parse_into_model context is #{context}"
  if uri.class == String
    uri = Uri.new(uri)
  end
  if base_uri
    if base_uri.class == String
      base_uri = Uri.new(base_uri)
    end
  else
    base_uri=uri 
  end
  if not context
    begin
      r = Redland.librdf_parser_parse_into_model(@parser,uri.uri,base_uri.uri,model.model)
    rescue RedlandError => err
      print "caught error"+ err
    end
  else #context
    raise RedlandError.new("Cannot make a Node from an object of #{context.class}") if not context
    context = Node.ensure(context)
    my_stream = Redland::librdf_parser_parse_as_stream(@parser,uri.uri,base_uri.uri)
    Redland.librdf_model_context_add_statements(model.model,context,my_stream)
    #self.parse_as_stream(uri,base_uri){|s| model.add_statement(s,context)}
  end

end

parse_string_as_stream(string,base_uri) click to toggle source

Parse the syntax in string with required base Uri base_uri

Returns a Stream or yields Statement if block given. Returns nil on failure.

# File rdf/redland/parser.rb, line 118
def parse_string_as_stream(string,base_uri)
  if base_uri.class == String then base_uri = Uri.new(base_uri) end
  if not base_uri then raise RedlandError("A base URI is required when parsing a string") end
  my_stream = Redland::librdf_parser_parse_string_as_stream(@parser,string,base_uri.uri)
  return nil if !my_stream
  stream = Stream.new(my_stream,self)
  return stream if !block_given?
  while not stream.end?
    yield stream.current
    stream.next
  end
end

parse_string_into_model(model,string,base_uri=nil,context=@context) click to toggle source

Parse the syntax in String string with required Uri base_uri into Model model. if context is given then the context information is stored as well

NOTE: The order of the arguments to this method is different from the C API and other language bindings.

# File rdf/redland/parser.rb, line 136
def parse_string_into_model(model,string,base_uri=nil,context=@context)
  if base_uri.class == String then base_uri = Uri.new(base_uri)end
  if not base_uri then raise RedlandError.new("A base URI is required when parsing a string") end
  if not context
    return (Redland::librdf_parser_parse_string_into_model(@parser,string,base_uri.uri,model.model)== 0)
  else
    self.parse_string_as_stream(string,base_uri.uri){|s| model.add_statement(s,context)}
  end        
end

setFeature(uri,value) click to toggle source

Set a parser feature. The feature is named Uri uri and the value is a Node.

# File rdf/redland/parser.rb, line 159
def setFeature(uri,value)
  if uri.class == String then uri = Uri.new(uri) end
  if value.class == String then value = Node.new(:literal=>value) end
  return (Redland::librdf_parser_set_feature(@parser,uri.uri,value.node) == 0)
end

smush_file(model,uri,base_uri=nil,context=nil,idents=@idents) click to toggle source

# File rdf/redland/parser.rb, line 190
def smush_file(model,uri,base_uri=nil,context=nil,idents=@idents)
  to_change = {}
  temp_model = Model.new()
  self.parse_into_model(temp_model,uri,base_uri,context)
  idents.each do |ident|
    temp_model.find(nil,ident,nil){|s,p,o|
      old_id = s
      new_id = model.subject(p,o)
      if new_id
        to_change[old_id.to_s]= new_id if !to_change.key?(old_id.to_s)
      end
    }
  end
  #puts to_change
  temp_model.triples do |s,p,o|
    s = to_change[s.to_s] if to_change.key?(s.to_s)
    model.add(s,p,o,context)
  end
  
end

smush_string(string,model,idents=@idents) click to toggle source

# File rdf/redland/parser.rb, line 169
def smush_string(string,model,idents=@idents)
  to_change = {}
  temp_model = Model.new()
  self.parse_string_into_model(temp_model,string,'http://xml.com')
  idents.each do |ident|
    temp_model.find(nil,ident,nil){|s,p,o|
      old_id = s
      new_id = model.subject(p,o)
      if new_id
        to_change[old_id.to_s]= new_id if !to_change.key?(old_id.to_s)
      end
    }
  end
  #puts to_change
  temp_model.triples do |s,p,o|
    s = to_change[s.to_s] if to_change.key?(s.to_s)
    model.add(s,p,o)
  end
  
end

Home Classes Methods

In Files

Parent

Methods

Files

Class/Module Index

Redland::Parser

Attributes

Public Class Methods

Public Instance Methods