Ron Savage > Tree-Simple-VisitorFactory > Tree::Simple::Visitor::GetAllDescendents

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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.

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