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 = $visitor->getResult() || die "No Tree found";
Given a node value and Tree::Simple hierarchy, this Visitor will attempt to find
the node with the same node value.
- new
- There are no arguments to the constructor the object will be in its
default state. You can use the
"setNodeFilter",
"setTraversalMethod",
"includeTrunk" and
"searchForNodeValue" methods to
customize its behavior.
- includeTrunk ($boolean)
- Based upon the value of $boolean, this will tell
the visitor to include the trunk of the tree in the search as well.
- setTraversalMethod ($visitor)
- By default we will use the Tree::Simple 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 $visitor object
implementing that traversal type to this method (See
Tree::Simple::Visitor::BreadthFirstTraversal,
Tree::Simple::Visitor::PreOrderTraversal and
Tree::Simple::Visitor::PostOrderTraversal).
- searchForNodeValue ($node_value)
- This is the node value we will attempt to find within the tree.
- setNodeFilter ($filter_function)
- This method accepts a CODE reference as its
$filter_function argument and throws an exception
if it is not a code reference. This code reference is used to further
check the tree nodes as they are searched and so can be used to customize
search behavior. For instance, you could to check against the node value
as well as some other criteria. The filter function should accept a single
argument, which is the current Tree::Simple object and return either true
(1) on success, or false
(0) on failure.
- visit ($tree)
- This is the method that is used by the Tree::Simple
"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.
- getResult
- This method will return the tree found with the specified node value (set
by the "searchForNodeValue" method) or
"undef" if no tree is found.
<https://github.com/ronsavage/Tree-Simple-VisitorFactory>
Bugs should be reported via the CPAN bug tracker at
<https://github.com/ronsavage/Tree-Simple-VisitorFactory/issues>
See the CODE COVERAGE section in Tree::Simple::VisitorFactory for more
information.
These Visitor classes are all subclasses of Tree::Simple::Visitor, which
can be found in the Tree::Simple module, you should refer to that
module for more information.
stevan little, <stevan@iinteractive.com>
Copyright 2004, 2005 by Infinity Interactive, Inc.
<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.