oracular (3) YAML::Node.3pm.gz

NAME

       YAML::Node - A generic data node that encapsulates YAML information

SYNOPSIS

           use YAML;
           use YAML::Node;

           my $ynode = YAML::Node->new({}, 'ingerson.com/fruit');
           %$ynode = qw(orange orange apple red grape green);
           print Dump $ynode;

       yields:

           --- !ingerson.com/fruit
           orange: orange
           apple: red
           grape: green

DESCRIPTION

       A generic node in YAML is similar to a plain hash, array, or scalar node in Perl except that it must also
       keep track of its type. The type is a URI called the YAML type tag.

       YAML::Node is a class for generating and manipulating these containers. A YAML node (or ynode) is a tied
       hash, array or scalar. In most ways it behaves just like the plain thing. But you can assign and retrieve
       and YAML type tag URI to it. For the hash flavor, you can also assign the order that the keys will be
       retrieved in. By default a ynode will offer its keys in the same order that they were assigned.

       YAML::Node has a class method call new() that will return a ynode. You pass it a regular node and an
       optional type tag. After that you can use it like a normal Perl node, but when you YAML::Dump it, the
       magical properties will be honored.

       This is how you can control the sort order of hash keys during a YAML serialization. By default, YAML
       sorts keys alphabetically. But notice in the above example that the keys were Dumped in the same order
       they were assigned.

       YAML::Node exports a function called ynode(). This function returns the tied object so that you can call
       special methods on it like ->keys().

       keys() works like this:

           use YAML;
           use YAML::Node;

           %$node = qw(orange orange apple red grape green);
           $ynode = YAML::Node->new($node);
           ynode($ynode)->keys(['grape', 'apple']);
           print Dump $ynode;

       produces:

           ---
           grape: green
           apple: red

       It tells the ynode which keys and what order to use.

       ynodes will play a very important role in how programs use YAML. They are the foundation of how a Perl
       class can marshall the Loading and Dumping of its objects.

       The upcoming versions of YAML.pm will have much more information on this.

AUTHOR

       Ingy döt Net <ingy@cpan.org>

COPYRIGHT

       Copyright 2001-2014. Ingy döt Net

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

       See <http://www.perl.com/perl/misc/Artistic.html>