NAME

RDF::Trine::Exporter::GraphViz - Serialize RDF graphs as dot graph diagrams

VERSION

version 0.141

SYNOPSIS

  use RDF::Trine::Exporter::GraphViz;

  my $ser = RDF::Trine::Exporter::GraphViz->new( as => 'dot' );
  my $dot = $ser->to_string( $rdf );

  $ser->to_file( 'graph.svg', $rdf );

  # highly configurable
  my $g = RDF::Trine::Exporter::GraphViz->new(
      namespaces => {
          foaf => 'http://xmlns.com/foaf/0.1/'
      },
      alias => {
          'http://www.w3.org/2002/07/owl#sameAs' => '=',
      },
      prevar => '$',  # variables as '$x' instead of '?x'
      url    => 1,    # hyperlink all URIs

      # see below for more configuration options
  );
  $g->to_file( 'test.svg', $model );

DESCRIPTION

RDF::Trine::Model includes a nice but somehow misplaced and non-customizable method as_graphviz. This module implements an extended version, put in a extends this method in a RDF::Trine::Exporter object. (actually it is a subclass of RDF::Trine::Serializer as long as RDF::Trine has no common class RDF::Trine::Exporter). This module also includes a command line script rdfdot to create graph diagrams from RDF data.

METHODS

This modules derives from RDF::Trine::Serializer with all of its methods (a future version may be derived from RDF::Trine::Exporter). The following methods are of interest in particular:

new ( %options )

Creates a new serializer with configuration options as described below.

to_file ( $file, $rdf [, %options ] )

Serialize RDF data, provided as RDF::Trine::Iterator or as RDF::Trine::Model to a file. $file can be a filehandle or file name. The serialization format is automatically derived from known file extensions.

to_string( $rdf [ %options ] )

Serialize RDF data, provided as RDF::Trine::Iterator or as RDF::Trine::Model to a string.

as_graphviz ( $rdf [, %options ] )

Creates and returns a GraphViz object for further processing. You must provide RDF data as RDF::Trine::Iterator or as RDF::Trine::Model.

media_types

Returns the exporter's mime type. For instance if you create an exporter with as => 'svg', this method returns ('image/svg+xml').

serialize_model_to_file ( $file, $model [, %options ] )

Provided as alias for to_file for compatibility with other RDF::Trine::Exporter classes.

serialize_model_to_string ( $model [, %options ] )

Provided as alias for to_string for compatibility with other RDF::Trine::Exporter classes.

serialize_iterator_to_string ( $iterator [, %options ] )

Serialize a RDF::Trine::Iterator as graph diagram to a string.

iterator_as_graphviz ( $iterator )

Internal core method, used by to_string and to_file, which one should better call instead.

CONFIGURATION

The following configuration options can be set when creating a new object.

as

Specific serialization format with dot as default. Supported formats include canonical DOT format (dot), Graphics Interchange Format (gif), JPEG File Interchange Format (jpeg), Portable Network Graphics (png), Scalable Vector Graphics (svg and svgz), server side HTML imape map (imap or map), client side HTML image map (cmapx), PostScript (ps), Hewlett Packard Graphic Language (hpgl), Printer Command Language (pcl), FIG format (fig), Maker Interchange Format (mif), Wireless BitMap format (wbmp), and Virtual Reality Modeling Language (vrml).

mime

Mime type. By default automatically set based on as.

style

General graph style options as hash reference. Defaults to { rankdir => 'TB', concentrate => 1 }.

node

Hash reference with general options to style nodes. Defaults to { shape => 'plaintext', color => 'gray' }.

resource

Hash reference with options to style resource nodes. Defaults to { shape => 'box', style => 'rounded', fontcolor => 'blue' }.

literal

Hash reference with options to style literal nodes. Defaults to { shape => 'box' }.

blank

Hash reference with options to style blank nodes. Defaults to { label => '', shape => 'point', fillcolor => 'white', color => 'gray', width => '0.3' }.

edge

Code referece with a function that get passed a predicate and variable $_ set to the predicate's URI. The function must return undef to skip the RDF statement or a hash reference with options to style the edge.

url

Add clickable URLs to nodes You can either provide a boolean value or a code reference that returns an URL when given a RDF::Trine::Node::Resource.

alias

Hash reference with URL aliases to show as resource and predicate labels.

variable

Hash reference with options to style variable nodes. Defaults to { fontcolor => 'darkslategray' }.

prevar

Which character to prepend to variable names. Defaults to '?'. You can also set it to '$'. By now the setting does not affect variables in Notation3 formulas.

root

An URI that is marked as 'root' node.

title

Add a title to the graph.

namespaces

Hash reference with mapping from prefixes to URI namespaces to abbreviate URIs. By default the prefix mapping from RDF::NS is used.

LIMITATIONS

This serializer does not support negotiate on purpose. It may optionally be enabled in a future version. GraphViz may fail on large graphs, its error message is not catched yet. Configuration in general is not fully covered by unit tests. Identifiers of blank nodes are not included.

AUTHOR

Jakob Voß <voss@gbv.de>

COPYRIGHT AND LICENSE

This software is copyright (c) 2012 by Jakob Voß.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm RDF::Trine::Exporter::GraphViz

perl -MCPAN -e shell
install RDF::Trine::Exporter::GraphViz