NAME¶
Tree::Simple::Visitor::FindByNodeValue - A Visitor for finding an element in a
Tree::Simple hierarchy by node value
SYNOPSIS¶
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 = $visitor->getResult() || die "No Tree found";
DESCRIPTION¶
Given a node value and Tree::Simple hierarchy, this Visitor will attempt to find
the node with the same node value.
METHODS¶
- new
- There are no arguments to the constructor the object will be in its
default state. You can use the "setNodeFilter",
"setTraversalMethod", "includeTrunk" and
"searchForNodeValue" methods to customize its behavior.
- includeTrunk ($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 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 $visitor object implementing that traversal type
to this method (See Tree::Simple::Visitor::BreadthFirstTraversal,
Tree::Simple::Visitor::PreOrderTraversal and
Tree::Simple::Visitor::PostOrderTraversal).
- searchForNodeValue ($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 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.
- 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.
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.
CODE COVERAGE¶
See the
CODE COVERAGE section in Tree::Simple::VisitorFactory for more
information.
SEE ALSO¶
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.
AUTHOR¶
stevan little, <stevan@iinteractive.com>
COPYRIGHT AND LICENSE¶
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.