Tree::Simple::Visitor:UserdContributed PerlTree::Simple::Visitor::FindByUID(3)NAMETree::Simple::Visitor::FindByUID - A Visitor for finding an element in
a Tree::Simple hierarchy by UID
SYNOPSIS
use Tree::Simple::Visitor::FindByUID;
# create a visitor object
my $visitor = Tree::Simple::Visitor::FindByUID->new();
# set the search path for our tree
$visitor->searchForUID("MyTreeUID");
# 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 = $visitor->getResult() || die "No Tree found";
DESCRIPTION
Given a UID and Tree::Simple hierarchy, this Visitor will attempt to
find the node with the same UID.
METHODS
new There are no arguments to the constructor the object will be in its
default state. You can use the "setNodeFilter",
"setTraversalMethod", "includeTrunk" and "searchForUID" methods to
customize its behavior.
includeTrunk ($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 $visitor object
implementing that traversal type to this method (See
Tree::Simple::Visitor::BreadthFirstTraversal,
Tree::Simple::Visitor::PreOrderTraversal and
Tree::Simple::Visitor::PostOrderTraversal).
searchForUID ($UID)
This is the UID we will attempt to find within the tree.
setNodeFilter ($filter_function)
This method accepts a CODE reference as its $filter_function
argument and throws an exception if it is not a code reference.
This code reference is used to further check the tree nodes as they
are searched and so can be used to customize search behavior. For
instance, you could to check against the UID as well as some other
criteria. The filter function should accept a single argument,
which is the current Tree::Simple object and return either true (1)
on success, or false (0) on failure.
visit ($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 UID (set
by the "searchForUID" 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
inforamtion.
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.
ACKNOWLEDGEMENTS
Thanks to Vitor Mori for the idea for this Visitor.
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.
perl v5.14.12005-07-1Tree::Simple::Visitor::FindByUID(3)
