# phpman > man > YAML::Node(3pm)

## NAME
    [YAML::Node](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown) - A generic data node that encapsulates YAML information

## SYNOPSIS
        use YAML;
        use [YAML::Node](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown);

        my $ynode = [YAML::Node](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown)->new({}, 'ingerson.com/fruit');
        %$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](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ADump/markdown) 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](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown) exports a function called ynode(). This function returns the tied object so that you
    can call special methods on it like ->keys().

### keys

        use YAML;
        use [YAML::Node](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown);

        %$node = qw(orange orange apple red grape green);
        $ynode = [YAML::Node](https://www.chedong.com/phpMan.php/perldoc/YAML%3A%3ANode/markdown)->new($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>>