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Tree::Simple::Visitor::GetAllDescendents(3pm) | User Contributed Perl Documentation | Tree::Simple::Visitor::GetAllDescendents(3pm) |
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¶
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.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
2021-02-20 | perl v5.32.1 |