Graph::Easy::Parser::VCG - Parse VCG or GDL text into Graph::Easy
# creating a graph from a textual description use Graph::Easy::Parser::VCG; my $parser = Graph::Easy::Parser::VCG->new(); my $graph = $parser->from_text( "graph: { \n" . " node: { title: "Bonn" }\n" . " node: { title: "Berlin" }\n" . " edge: { sourcename: "Bonn" targetname: "Berlin" }\n" . "}\n" ); print $graph->as_ascii(); print $parser->from_file('mygraph.vcg')->as_ascii();
Graph::Easy::Parser::VCG parses the text format from the VCG or GDL (Graph Description Language) use by tools like GCC and AiSee, and constructs a Graph::Easy object from it.
Graph::Easy::Parser::VCG
Graph::Easy
The resulting object can then be used to layout and output the graph in various formats.
The output will be a Graph::Easy object (unless overridden with use_class()), see the documentation for Graph::Easy what you can do with it.
use_class()
Attributes will be remapped to the proper Graph::Easy attribute names and values, as much as possible.
Anything else will be converted to custom attributes starting with "x-vcg-". So "dirty_edge_labels: yes" will become "x-vcg-dirty_edge_labels: yes".
Graph::Easy::Parser::VCG supports the same methods as its parent class Graph::Easy::Parser:
Graph::Easy::Parser
use Graph::Easy::Parser::VCG; my $parser = Graph::Easy::Parser::VCG->new();
Creates a new parser object. There are two valid parameters:
debug fatal_errors
Both take either a false or a true value.
my $parser = Graph::Easy::Parser::VCG->new( debug => 1 ); $parser->from_text('graph: { }');
$parser->reset();
Reset the status of the parser, clear errors etc. Automatically called when you call any of the from_XXX() methods below.
from_XXX()
$parser->use_class('node', 'Graph::Easy::MyNode');
Override the class to be used to constructs objects while parsing.
See Graph::Easy::Parser for further information.
my $graph = $parser->from_text( $text );
Create a Graph::Easy object from the textual description in $text.
$text
Returns undef for error, you can find out what the error was with error().
This method will reset any previous error, and thus the $parser object can be re-used to parse different texts by just calling from_text() multiple times.
$parser
from_text()
my $graph = $parser->from_file( $filename ); my $graph = Graph::Easy::Parser::VCG->from_file( $filename );
Creates a Graph::Easy object from the textual description in the file $filename.
$filename
The second calling style will create a temporary parser object, parse the file and return the resulting Graph::Easy object.
Returns undef for error, you can find out what the error was with error() when using the first calling style.
my $error = $parser->error();
Returns the last error, or the empty string if no error occurred.
$parser->parse_error( $msg_nr, @params);
Sets an error message from a message number and replaces embedded templates like ##param1## with the passed parameters.
##param1##
The parser has problems with the following things:
Some attributes are not remapped properly to what Graph::Easy expects, thus losing information, either because Graph::Easy doesn't support this feature yet, or because the mapping is incomplete.
Comments written in the source code itself are discarded. If you want to have comments on the graph, clusters, nodes or edges, use the attribute comment. These are correctly read in and stored, and then output into the different formats, too.
comment
Exports nothing.
Graph::Easy, Graph::Write::VCG.
Copyright (C) 2005 - 2008 by Tels http://bloodgate.com
See the LICENSE file for information.
To install Graph::Easy, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Graph::Easy
CPAN shell
perl -MCPAN -e shell install Graph::Easy
For more information on module installation, please visit the detailed CPAN module installation guide.