Commit | Line | Data |
3fea05b9 |
1 | |
2 | package Tree::Simple::Visitor::PreOrderTraversal; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
7 | our $VERSION = '0.01'; |
8 | |
9 | use base qw(Tree::Simple::Visitor); |
10 | |
11 | # make sure we use the "new" interface |
12 | # so we enforce it here |
13 | sub new { |
14 | my ($_class) = @_; |
15 | my $class = ref($_class) || $_class; |
16 | my $visitor = $class->SUPER::new(); |
17 | return $visitor; |
18 | } |
19 | |
20 | 1; |
21 | |
22 | __END__ |
23 | |
24 | =head1 NAME |
25 | |
26 | Tree::Simple::Visitor::PreOrderTraversal - A Visitor for pre-order traversal a Tree::Simple hierarchy |
27 | |
28 | =head1 SYNOPSIS |
29 | |
30 | use Tree::Simple::Visitor::PreOrderTraversal; |
31 | |
32 | # create an visitor |
33 | my $visitor = Tree::Simple::Visitor::PreOrderTraversal->new(); |
34 | |
35 | # pass our visitor to the tree |
36 | $tree->accept($visitor); |
37 | |
38 | # print our results |
39 | print join ", " => $visitor->getResults(); |
40 | |
41 | # this will print this: |
42 | # 1 1.1 1.1.1 1.2 2 2.1 3 3.1 |
43 | # assuming your tree is like this: |
44 | # 1 |
45 | # 1.1 |
46 | # 1.1.1 |
47 | # 1.2 |
48 | # 2 |
49 | # 2.1 |
50 | # 3 |
51 | # 3.1 |
52 | |
53 | =head1 DESCRIPTION |
54 | |
55 | Pre-order traversal is a depth-first traversal method in which the sub-tree's are processed I<after> the parent. It is essentially a wrapper around the base Tree::Simple::Visitor class, and is a seperate module here for completeness. (If you have a post-order, you should have a pre-order too). |
56 | |
57 | =head1 METHODS |
58 | |
59 | =over 4 |
60 | |
61 | =item B<new> |
62 | |
63 | There are no arguments to the constructor the object will be in its default state. You can use the C<setNodeFilter> method to customize its behavior. |
64 | |
65 | =item B<includeTrunk ($boolean)> |
66 | |
67 | Based upon the value of C<$boolean>, this will tell the visitor to include the trunk of the tree in the traversal as well. |
68 | |
69 | =item B<setNodeFilter ($filter_function)> |
70 | |
71 | This method accepts a CODE reference as its C<$filter_function> argument and throws an exception if it is not a code reference. This code reference is used to filter the tree nodes as they are collected. This can be used to customize output, or to gather specific information from a more complex tree node. The filter function should accept a single argument, which is the current Tree::Simple object. |
72 | |
73 | =item B<visit ($tree)> |
74 | |
75 | 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. |
76 | |
77 | =item B<getResults> |
78 | |
79 | This method returns the accumulated results of the application of the node filter to the tree. |
80 | |
81 | =back |
82 | |
83 | =head1 BUGS |
84 | |
85 | None that I am aware of. Of course, if you find a bug, let me know, and I will be sure to fix it. |
86 | |
87 | =head1 CODE COVERAGE |
88 | |
89 | See the B<CODE COVERAGE> section in L<Tree::Simple::VisitorFactory> for more inforamtion. |
90 | |
91 | =head1 SEE ALSO |
92 | |
93 | 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. |
94 | |
95 | =head1 AUTHOR |
96 | |
97 | stevan little, E<lt>stevan@iinteractive.comE<gt> |
98 | |
99 | =head1 COPYRIGHT AND LICENSE |
100 | |
101 | Copyright 2004, 2005 by Infinity Interactive, Inc. |
102 | |
103 | L<http://www.iinteractive.com> |
104 | |
105 | This library is free software; you can redistribute it and/or modify |
106 | it under the same terms as Perl itself. |
107 | |
108 | =cut |
109 | |