NAME¶
Tree::Simple::Visitor::GetAllDescendents - A Visitor for fetching all the
descendents of a Tree::Simple object
SYNOPSIS¶
use Tree::Simple::Visitor::GetAllDescendents;
# create an instance of our visitor
my $visitor = Tree::Simple::Visitor::GetAllDescendents->new();
# pass the visitor to a Tree::Simple object
$tree->accept($visitor);
# you can also get the descendents
# back as an array of node values
my @descendents = $visitor->getDescendents();
# for more complex node objects, you can specify
# a node filter which will be used to extract the
# information desired from each node
$visitor->setNodeFilter(sub {
my ($t) = @_;
return $t->getNodeValue()->description();
});
DESCRIPTION¶
Given a Tree::Simple instance this Visitor will return all the descendents
recursively on down the hierarchy.
METHODS¶
- new
- There are no arguments to the constructor the object will be in its
default state. You can use the
"setNodeFilter" method to customize its
behavior.
- setTraversalMethod ($visitor)
- By default we will use Tree::Simple's built in depth-first (pre-order)
traverse method. If however, you desire the descendents to be returned in
a different ordering, this can be accomplished using a different traversal
method, you can supply a $visitor object
implementing that traversal type to this method (See
Tree::Simple::Visitor::BreadthFirstTraversal,
Tree::Simple::Visitor::PreOrderTraversal and
Tree::Simple::Visitor::PostOrderTraversal).
- setNodeFilter ($filter_function)
- This method accepts a CODE reference as its
$filter_function argument and throws an exception
if it is not a code reference. This code reference is used to filter the
tree nodes as they are collected. This can be used to customize output, or
to gather specific information from a more complex tree node. The filter
function should accept a single argument, which is the current
Tree::Simple object.
- visit ($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.
- getAllDescendents
- This method will give back and array of descendents in depth-first order
(pre-order) or in the order specified by the
"setTraversalMethod". If called in
scalar context it will give an array reference, in list context it will
return a regular array. This method is the same as calling
"getResults".
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.