---
name: "Tree::Simple::Visitor::GetAllDescendents"
section: "3pm"
platform: "linux"
package: "libtree-simple-visitorfactory-perl"
version: "0.16-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Tree::Simple::Visitor::GetAllDescendents"
---

# Tree::Simple::Visitor::GetAllDescendents(3pm)

A Visitor for fetching all the descendents of a Tree::Simple object

## 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"`.

## Repository

\<https://github.com/ronsavage/Tree-Simple-VisitorFactory\>

## SUPPORT

Bugs should be reported via the CPAN bug tracker at

\<https://github.com/ronsavage/Tree-Simple-VisitorFactory/issues\>

## 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.