package Tree::Simple::Visitor::ToNestedArray;
use strict;
use warnings;
our $VERSION = '0.02';
use Scalar::Util qw(blessed);
use base qw(Tree::Simple::Visitor);
sub new {
my ($_class) = @_;
my $class = ref($_class) || $_class;
my $visitor = {};
bless($visitor, $class);
$visitor->_init();
return $visitor;
}
sub visit {
my ($self, $tree) = @_;
(blessed($tree) && $tree->isa("Tree::Simple"))
|| die "Insufficient Arguments : You must supply a valid Tree::Simple object";
# grab our filter (if we have one)
my $filter = $self->getNodeFilter();
my @results;
# get the array
$self->_buildArray($tree, \@results, $filter);
# add the trunk if we need to
@results = (
((defined($filter)) ?
$filter->($tree)
:
$tree->getNodeValue()),
[ @results ]
) if $self->includeTrunk();
# set results
$self->setResults(\@results);
}
sub _buildArray {
my ($self, $tree, $accumulator, $filter) = @_;
foreach my $child ($tree->getAllChildren()) {
push @{$accumulator} => (defined($filter) ? $filter->($child) : $child->getNodeValue());
push @{$accumulator} => $self->_buildArray($child, [], $filter) unless $child->isLeaf();
}
return $accumulator;
}
1;
__END__
=head1 NAME
Tree::Simple::Visitor::ToNestedArray - A Visitor for creating nested array trees from Tree::Simple objects.
=head1 SYNOPSIS
use Tree::Simple::Visitor::ToNestedArray;
my $visitor = Tree::Simple::Visitor::ToNestedArray->new();
# given this Tree::Simple tree
my $tree = Tree::Simple->new("Root")
->addChildren(
Tree::Simple->new("Child1")
->addChildren(
Tree::Simple->new("GrandChild1"),
Tree::Simple->new("GrandChild2")
),
Tree::Simple->new("Child2"),
);
# include the trunk (Root)
$visitor->includeTrunk(1);
# visit the tree
$tree->accept($visitor);
my $array_tree = $visitor->getResults();
# this then creates the equivalent nested array tree:
# [
# 'Root', [
# 'Child1', [
# 'GrandChild1',
# 'GrandChild2'
# ],
# 'Child2'
# ]
# ]
# if you don't include the trunk (Root) then ...
$tree->accept($visitor);
my $array_tree = $visitor->getResults();
# this then creates the following nested array tree:
# [
# 'Child1', [
# 'GrandChild1',
# 'GrandChild2'
# ],
# 'Child2'
# ]
=head1 DESCRIPTION
Given a tree constructed from a Tree::Simple heirarchy, this Visitor will create the equivalent tree of nested arrays.
=head1 METHODS
=over 4
=item B<new>
There are no arguments to the constructor the object will be in its default state. You can use the C<setNodeFilter> and C<includTrunk> methods to customize its behavior.
=item B<includTrunk ($boolean)>
Setting the C<$boolean> value to true (C<1>) will cause the node value of the tree's root to be included in the nested array output, setting it to false will do the opposite.
=item B<setNodeFilter ($filter_function)>
This method accepts a CODE reference as its C<$filter_function> argument and throws an exception if it is not a code reference. This code reference is used to filter the tree nodes as they are placed into the array tree. The C<$filter_function> is passed a Tree::Simple object, and is expected to return the value desired for inclusion into the array tree.
=item B<visit ($tree)>
This is the method that is used by Tree::Simple's C<accept> method. It can also be used on its own, it requires the C<$tree> argument to be a Tree::Simple object (or derived from a Tree::Simple object), and will throw and exception otherwise.
=item B<getResults>
This method will return the array tree constructed.
=back
=head1 BUGS
None that I am aware of. Of course, if you find a bug, let me know, and I will be sure to fix it.
=head1 CODE COVERAGE
See the B<CODE COVERAGE> section in L<Tree::Simple::VisitorFactory> for more inforamtion.
=head1 SEE ALSO
These Visitor classes are all subclasses of B<Tree::Simple::Visitor>, which can be found in the B<Tree::Simple> module, you should refer to that module for more information.
=head1 AUTHOR
stevan little, E<lt>stevan@iinteractive.comE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright 2004, 2005 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut