Redland RDF Application Framework - Ruby RDoc

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Class

Redland::Resource

In:

rdf/redland/resource.rb

Parent:

Node

include Redland

Methods

add_property delete_properties delete_property get_properties get_property new object_of_predicate set_context set_type type type= type? update_property

Attributes

model	[R]	The internal model this Resource is connected to
node	[R]	The internal librdf_node

Public Class methods

new(arg=nil,model=nil,new_node=true)

Create a Redland::Resource. Arg can be a String, or a Redland::Uri

[Source]

# File rdf/redland/resource.rb, line 16
    def initialize(arg=nil,model=nil,new_node=true)
      @context = nil
      case arg
      when nil
        @node = Redland.librdf_new_node_from_blank_identifier($world.world,nil)
      when String
        @node = Redland.librdf_new_node_from_uri_string($world.world,arg)
      when Uri
        @node = Redland.librdf_new_node_from_uri($world.world,arg.uri)
      when Node
        @node = Redland.librdf_new_node_from_node(arg.node)
      when SWIG::TYPE_p_librdf_node_s
        
        @node = new_node ? Redland.librdf_new_node_from_node(arg): arg
      end
      raise RedlandError.new("Node construction failed") if not @node
      ObjectSpace.define_finalizer(self,Node.create_finalizer(@node))

      model ||= Model.new
      @model = model
    end

Public Instance methods

add_property(p,o,context=nil)

Adds a statement to the model with the subject as the resource and p as the predicate and o as the object same as Model.add(this,p,o)

[Source]

# File rdf/redland/resource.rb, line 94
    def add_property(p,o,context=nil)
      @model.add(self,p,o,context)
      return self
    end

delete_properties()

Removes all of the properties from the model with this resource as the subject

[Source]

# File rdf/redland/resource.rb, line 108
    def delete_properties()
      self.get_properties().each{|st| @model.delete_statement(st)}
    end

delete_property(pred,context=nil)

Removes the property from the model with the predicate pred and optional context

[Source]

# File rdf/redland/resource.rb, line 101
    def delete_property(pred,context=nil)
      @model.delete(self,pred,self.get_property(pred),context)
      return self
    end

get_properties(pred=nil) {|st.object| ...}

Answer model.find(self,pred,nil) in the associated model If no predicate or block given, returns and array of statements matching model.find(self,nil,nil) If block_given? yields the predicate and the object

  resource.get_properties() do |p,o|
    puts "<td>#{p}</td><td>#{o}</td>"
  end

If pred given, answers model.find(self,pred,nil) if no block return an array of the object values

  nicknames = resource.get_properties(FOAF::NICK)

if block_given yields the objects which satisfy the predicate

  puts "Nicknames are"
    resource.get_properties(FOAF_NICK){|o| puts o}

[Source]

# File rdf/redland/resource.rb, line 60
    def get_properties(pred=nil)
      statements = @model.find(self,pred,nil)
      if pred
        if block_given?
          statements.each{|st| yield st.object}
        else
          statements.map{|st| st.object}
        end
      else
        return statements if not block_given?
        statements.each{ |st| yield st.predicate,st.object}
      end
    end

get_property(p)

Answer model.find(self,p,nil) in the associated model. If there are several such statements, any one of them may be returned

[Source]

# File rdf/redland/resource.rb, line 40
    def get_property(p)
      @model.object(self,p)
    end

object_of_predicate(pred = nil) {|sub| ...}

Finds all objects of a given predicate. Takes an optional block, yielding each statement if given.

[Source]

# File rdf/redland/resource.rb, line 76
    def object_of_predicate(pred = nil)
      # statements = @model.find(nil,pred,self)
      if pred
        if block_given?
          @model.subjects(pred,self){|sub| yield sub}
        else
          return @model.subjects(pred,self)
        end
      else
        statements = @model.find(nil,nil,self)
        return statements if not block_given?
        statements.each { |st| yield st.subject,st.predicate}
      end
    end

set_context(context)

Defines a context for this resource

[Source]

# File rdf/redland/resource.rb, line 146
    def set_context(context)
      @context = context
    end

set_type(type,context=@context)

Set the type of this Resource

[Source]

# File rdf/redland/resource.rb, line 139
    def set_type(type,context=@context)
      self.delete_property(TYPE)
      self.add_property(TYPE,type,context)
      return self
    end

type()

returns the RDF type of this Resource where RDF type is <www.w3.org/1999/02/22-rdf-syntax-ns#TYPE>

[Source]

# File rdf/redland/resource.rb, line 134
    def type
      self.get_property(TYPE)
    end

type=(type,context=@context)

Sets the RDF type of this Resource where RDF type is <www.w3.org/1999/02/22-rdf-syntax-ns#TYPE>

[Source]

# File rdf/redland/resource.rb, line 126
    def type=(type,context=@context)
      self.delete_property(TYPE)
      self.add_property(TYPE,type,context)
      return self
    end

type?(type)

Determine if this resource is of a given type

[Source]

# File rdf/redland/resource.rb, line 113
    def type?(type)
      self.model.find(self,TYPE,type).size != 0
    end

update_property(prop,value,context=nil)

Change the value of the given property

[Source]

# File rdf/redland/resource.rb, line 118
    def update_property(prop,value,context=nil)
      self.delete_property(prop)
      self.add_property(prop,value,context)
      return self
   end

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