Tree::Simple::Visitor::FindByNodeValue - A Visitor for finding an element in a Tree::Simple hierarchy by node value
use Tree::Simple::Visitor::FindByNodeValue; # create a visitor object my $visitor = Tree::Simple::Visitor::FindByNodeValue->new(); # set the search path for our tree $visitor->searchForNodeValue("My Tree Node"); # pass the visitor to a tree $tree->accept($visitor); # fetch the result, which will # be the Tree::Simple object that # we have found, or undefined my $result = $visitor->getResult() || die "No Tree found";
Given a node value and Tree::Simple hierarchy, this Visitor will attempt to find the node with the same node value.
There are no arguments to the constructor the object will be in its default state. You can use the
searchForNodeValue methods to customize its behavior.
Based upon the value of
$boolean, this will tell the visitor to include the trunk of the tree in the search as well.
By default we will use Tree::Simple's built in depth-first (pre-order) traverse method. If however, you desire the tree to be search in a different ordering, this can be accomplished using a different traversal method, you can supply a
$visitor object implementing that traversal type to this method (See Tree::Simple::Visitor::BreadthFirstTraversal, Tree::Simple::Visitor::PreOrderTraversal and Tree::Simple::Visitor::PostOrderTraversal).
This is the node value we will attempt to find within the tree.
This method accepts a CODE reference as its
$filter_function argument and throws an exception if it is not a code reference. This code reference is used to further check the tree nodes as they are searched and so can be used to customize search behavior. For instance, you could to check against the node value as well as some other criteria. The filter function should accept a single argument, which is the current Tree::Simple object and return either true (
1) on success, or false (
0) on failure.
This is the method that is used by Tree::Simple's
accept method. It can also be used on its own, it requires the
$tree argument to be a Tree::Simple object (or derived from a Tree::Simple object), and will throw and exception otherwise.
This method will return the tree found with the specified node value (set by the
searchForNodeValue method) or
undef if no tree is found.
None that I am aware of. Of course, if you find a bug, let me know, and I will be sure to fix it.
See the CODE COVERAGE section in Tree::Simple::VisitorFactory for more inforamtion.
stevan little, <email@example.com>
Copyright 2004, 2005 by Infinity Interactive, Inc.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.