1
2package Tree::Simple::Visitor::ToNestedArray;
3
4use strict;
5use warnings;
6
7our $VERSION = '0.02';
8
9use Scalar::Util qw(blessed);
10
11use base qw(Tree::Simple::Visitor);
12
13sub new {
14    my ($_class) = @_;
15    my $class = ref($_class) || $_class;
16    my $visitor = {};
17    bless($visitor, $class);
18    $visitor->_init();
19    return $visitor;
20}
21
22sub visit {
23	my ($self, $tree) = @_;
24	(blessed($tree) && $tree->isa("Tree::Simple"))
25		|| die "Insufficient Arguments : You must supply a valid Tree::Simple object";
26    # grab our filter (if we have one)
27    my $filter = $self->getNodeFilter();
28    my @results;
29    # get the array
30    $self->_buildArray($tree, \@results, $filter);
31    # add the trunk if we need to
32    @results = (
33            ((defined($filter)) ?
34                    $filter->($tree)
35                    :
36                    $tree->getNodeValue()),
37            [ @results ]
38        ) if $self->includeTrunk();
39    # set results
40    $self->setResults(\@results);
41}
42
43sub _buildArray {
44    my ($self, $tree, $accumulator, $filter) = @_;
45    foreach my $child ($tree->getAllChildren()) {
46        push @{$accumulator} => (defined($filter) ? $filter->($child) : $child->getNodeValue());
47        push @{$accumulator} => $self->_buildArray($child, [], $filter) unless $child->isLeaf();
48    }
49    return $accumulator;
50}
51
521;
53
54__END__
55
56=head1 NAME
57
58Tree::Simple::Visitor::ToNestedArray - A Visitor for creating nested array trees from Tree::Simple objects.
59
60=head1 SYNOPSIS
61
62  use Tree::Simple::Visitor::ToNestedArray;
63
64  my $visitor = Tree::Simple::Visitor::ToNestedArray->new();
65
66  # given this Tree::Simple tree
67  my $tree = Tree::Simple->new("Root")
68                ->addChildren(
69                    Tree::Simple->new("Child1")
70                        ->addChildren(
71                            Tree::Simple->new("GrandChild1"),
72                            Tree::Simple->new("GrandChild2")
73                        ),
74                    Tree::Simple->new("Child2"),
75                );
76
77  # include the trunk (Root)
78  $visitor->includeTrunk(1);
79
80  # visit the tree
81  $tree->accept($visitor);
82
83  my $array_tree = $visitor->getResults();
84  # this then creates the equivalent nested array tree:
85  # [
86  # 'Root', [
87  #     'Child1', [
88  #             'GrandChild1',
89  #             'GrandChild2'
90  #             ],
91  #     'Child2'
92  #     ]
93  # ]
94
95  # if you don't include the trunk (Root) then ...
96  $tree->accept($visitor);
97
98  my $array_tree = $visitor->getResults();
99  # this then creates the following nested array tree:
100  # [
101  #   'Child1', [
102  #           'GrandChild1',
103  #           'GrandChild2'
104  #           ],
105  #   'Child2'
106  # ]
107
108=head1 DESCRIPTION
109
110Given a tree constructed from a Tree::Simple heirarchy, this Visitor will create the equivalent tree of nested arrays.
111
112=head1 METHODS
113
114=over 4
115
116=item B<new>
117
118There are no arguments to the constructor the object will be in its default state. You can use the C<setNodeFilter> and C<includTrunk> methods to customize its behavior.
119
120=item B<includTrunk ($boolean)>
121
122Setting the C<$boolean> value to true (C<1>) will cause the node value of the tree's root to be included in the nested array output, setting it to false will do the opposite.
123
124=item B<setNodeFilter ($filter_function)>
125
126This 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.
127
128=item B<visit ($tree)>
129
130This is the method that is used by Tree::Simple's C<accept> method. It can also be used on its own, it requires the C<$tree> argument to be a Tree::Simple object (or derived from a Tree::Simple object), and will throw and exception otherwise.
131
132=item B<getResults>
133
134This method will return the array tree constructed.
135
136=back
137
138=head1 BUGS
139
140None that I am aware of. Of course, if you find a bug, let me know, and I will be sure to fix it.
141
142=head1 CODE COVERAGE
143
144See the B<CODE COVERAGE> section in L<Tree::Simple::VisitorFactory> for more inforamtion.
145
146=head1 SEE ALSO
147
148These 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.
149
150=head1 AUTHOR
151
152stevan little, E<lt>stevan@iinteractive.comE<gt>
153
154=head1 COPYRIGHT AND LICENSE
155
156Copyright 2004, 2005 by Infinity Interactive, Inc.
157
158L<http://www.iinteractive.com>
159
160This library is free software; you can redistribute it and/or modify
161it under the same terms as Perl itself.
162
163=cut
164