# NAME

[GraphViz2::Data::Grapher](https://metacpan.org/pod/GraphViz2::Data::Grapher) - Visualize a data structure as a graph

# Synopsis

        #!/usr/bin/env perl

        use strict;
        use warnings;

        use File::Spec;

        use GraphViz2;
        use GraphViz2::Data::Grapher;

        my($sub) = sub{};
        my($s)   =
        {
                A =>
                {
                        a =>
                        {
                        },
                        bbbbbb => $sub,
                        c123   => $sub,
                        d      => \$sub,
                },
                C =>
                {
                        b =>
                        {
                                a =>
                                {
                                        a =>
                                        {
                                        },
                                        b => sub{},
                                        c => 42,
                                },
                        },
                },
                els => [qw(element_1 element_2 element_3)],
        };

        my($graph) = GraphViz2 -> new
                (
                 edge   => {color => 'grey'},
                 global => {directed => 1},
                 graph  => {rankdir => 'TB'},
                 node   => {color => 'blue', shape => 'oval'},
                );

        my($g)           = GraphViz2::Data::Grapher->new(graph => $graph);
        my($format)      = shift || 'svg';
        my($output_file) = shift || File::Spec -> catfile('html', "parse.data.$format");

        $g -> create(name => 's', thing => $s);
        $graph -> run(format => $format, output_file => $output_file);

        # If you did not provide a GraphViz2 object, do this
        # to get access to the auto-created GraphViz2 object.

        #$g -> create(name => 's', thing => $s);
        #$g -> graph -> run(format => $format, output_file => $output_file);

        # Or even

        #$g -> create(name => 's', thing => $s)
        #-> graph
        #-> run(format => $format, output_file => $output_file);

See scripts/parse.data.pl (["Scripts Shipped with this Module" in GraphViz2](https://metacpan.org/pod/GraphViz2#Scripts-Shipped-with-this-Module)).

# Description

Takes a Perl data structure and recursively converts it into [Tree::DAG\_Node](https://metacpan.org/pod/Tree::DAG_Node) object, and then graphs it.

You can write the result in any format supported by [Graphviz](http://www.graphviz.org/).

Here is the list of [output formats](http://www.graphviz.org/content/output-formats).

Within the graph:

- o Array names are preceeded by '@'
- o Code references are preceeded by '&'
- o Hash names are preceeded by '%'
- o Scalar names are preceeded by '$'

Hence, a hash ref will look like '%$h'.

Further, objects of different type have different shapes.

# Constructor and Initialization

## Calling new()

`new()` is called as `my($obj) = GraphViz2::Data::Grapher -> new(k1 => v1, k2 => v2, ...)`.

It returns a new object of type `GraphViz2::Data::Grapher`.

Key-value pairs accepted in the parameter list:

- o graph => $graphviz\_object

    This option specifies the GraphViz2 object to use. This allows you to configure it as desired.

    The default is GraphViz2 -> new. The default attributes are the same as in the synopsis, above,
    except for the graph label of course.

    This key is optional.

# Methods

## create(name => $name, thing => $thing)

Creates the graph, which is accessible via the graph() method, or via the graph object you passed to new().

Returns $self to allow method chaining.

$name is the string which will be placed in the root node of the tree.

If $s = {...}, say, use 's', not '$s', because '%$' will be prefixed automatically to the name,
because $s is a hashref.

$thing is the data stucture to graph.

## graph()

Returns the graph object, either the one supplied to new() or the one created during the call to new().

## tree()

Returns the tree object (of type [Tree::DAG\_Node](https://metacpan.org/pod/Tree::DAG_Node)) built before it is traversed to generate the nodes and edges.

# Scripts Shipped with this Module

## scripts/parse.data.pl

Demonstrates graphing a Perl data structure.

Outputs to ./html/parse.data.svg by default.

## scripts/parse.html.pl

Demonstrates using [XML::Bare](https://metacpan.org/pod/XML::Bare) to parse HTML.

Inputs from ./t/sample.html, and outputs to ./html/parse.html.svg by default.

## scripts/parse.xml.bare.pl

Demonstrates using [XML::Bare](https://metacpan.org/pod/XML::Bare) to parse XML.

Inputs from ./t/sample.xml, and outputs to ./html/parse.xml.bare.svg by default.

# Thanks

Many thanks are due to the people who chose to make [Graphviz](http://www.graphviz.org/) Open Source.

And thanks to [Leon Brocard](http://search.cpan.org/~lbrocard/), who wrote [GraphViz](https://metacpan.org/pod/GraphViz), and kindly gave me co-maint of the module.

# Author

[GraphViz2](https://metacpan.org/pod/GraphViz2) was written by Ron Savage _<ron@savage.net.au>_ in 2011.

Home page: [http://savage.net.au/index.html](http://savage.net.au/index.html).

# Copyright

Australian copyright (c) 2011, Ron Savage.

        All Programs of mine are 'OSI Certified Open Source Software';
        you can redistribute them and/or modify them under the terms of
        The Perl License, a copy of which is available at:
        http://dev.perl.org/licenses/
