NAME¶
Tree::Simple::VisitorFactory - A factory object for dispensing Visitor objects
SYNOPSIS¶
use Tree::Simple::VisitorFactory;
my $tf = Tree::Simple::VisitorFactory->new();
my $visitor = $tf->get("PathToRoot");
# or call it as a class method
my $visitor = Tree::Simple::VisitorFactory->getVisitor("PathToRoot");
DESCRIPTION¶
This object is really just a factory for dispensing Tree::Simple::Visitor::*
objects. It is not required to use this package in order to use all the
Visitors, it is just a somewhat convenient way to avoid having to type their
long class names.
I considered making this a Singleton, but I did not because I thought that some
people might not want that. I know that I am very picky about using
Singletons, especially in multiprocess environments like mod_perl, so I
implemented the smallest instance I knew how to, and made sure all other
methods could be called as class methods too.
METHODS¶
- new
- Returns an minimal instance of this object, basically just a reference
back to the package (literally, see the source if you care).
- get ($visitor_type)
- Attempts to load the $visitor_type and returns an instance of it if
successful. If no $visitor_type is specified an exception is thrown, if
$visitor_type fails to load, and exception is thrown.
- getVisitor ($visitor_type)
- This is an alias of "get".
AVAILABLE VISITORS¶
This distribution provides a number of Visitor objects which can be loaded just
by giving their name. Below is a description of the available Visitors and a
sort description of what they do. I have attempted to classify the Visitors
into groups which are related to their use.
This factory will load any module contained inside the
Tree::Simple::Visitor::* namespace. Given a name, it will attempt to
"require" the module
Tree::Simple::Visitor::<Name >.pm. This
allows others to create Visitors which can be accessed with this factory,
without needed to include them in this distribution.
- PathToRoot
- Given a Tree::Simple object, this Visitor will find the path back to the
tree's root node.
- FindByPath
- Given a path and Tree::Simple hierarchy, this Visitor will attempt to find
the node specified by the path.
- FindByUID
- Given a UID and Tree::Simple hierarchy, this Visitor will attempt to find
the node with the same UID.
- FindByNodeValue
- Given a node value and Tree::Simple hierarchy, this Visitor will attempt
to find the node with the same node value.
Traversal Visitors¶
- BreadthFirstTraversal
- This implements a breadth-first traversal of a Tree::Simple
hierarchy.
- PostOrderTraversal
- Post-order traversal is a variation of the depth-first traversal in which
the sub-tree's are processed before the parent.
- PreOrderTraversal
- Pre-order traversal is a depth-first traversal method in which the
sub-tree's are processed after the parent.
FileSystem Visitors¶
- LoadDirectoryTree
- This visitor can be used to load a directory tree into a Tree::Simple
hierarchy.
- CreateDirectoryTree
- This visitor can be used to create a set of directories and files from a
Tree::Simple object hierarchy.
Conversion Visitors¶
- FromNestedArray
- Given a tree constructed from nested arrays, this Visitor will create the
equivalent Tree::Simple hierarchy.
- ToNestedArray
- Given a Tree::Simple hierarchy, this Visitor will create the equivalent
tree constructed from nested arrays.
- FromNestedHash
- Given a tree constructed from nested hashs, this Visitor will create the
equivalent Tree::Simple hierarchy.
- ToNestedHash
- Given a Tree::Simple hierarchy, this Visitor will create the equivalent
tree constructed from nested hashes.
Reflective Visitors¶
- LoadClassHierarchy
- Given a class name or instance, this Visitor will create a Tree::Simple
hierarchy which models the classes inheritance hierarchy.
Misc. Visitors¶
- GetAllDescendents
- Given a Tree::Simple instance this Visitor will return all the descendents
recursively on down the hierarchy.
- Sort
- This implements a multi-level sort of a Tree::Simple hierarchy.
- VariableDepthClone
- A Visitor for cloning parts of Tree::Simple hierarchy
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¶
I use
Devel::Cover to test the code coverage of my tests, below is the
Devel::Cover report on this module test suite.
-------------------------------------------- ------ ------ ------ ------ ------ ------ ------
File stmt branch cond sub pod time total
-------------------------------------------- ------ ------ ------ ------ ------ ------ ------
Tree/Simple/VisitorFactory.pm 100.0 100.0 n/a 100.0 100.0 0.4 100.0
Tree/Simple/Visitor/BreadthFirstTraversal.pm 100.0 100.0 66.7 100.0 100.0 2.5 96.3
Tree/Simple/Visitor/PostOrderTraversal.pm 100.0 100.0 77.8 100.0 100.0 1.7 96.3
Tree/Simple/Visitor/PreOrderTraversal.pm 100.0 n/a 33.3 100.0 100.0 0.7 90.5
Tree/Simple/Visitor/CreateDirectoryTree.pm 100.0 85.7 86.7 100.0 100.0 3.4 95.8
Tree/Simple/Visitor/LoadClassHierarchy.pm 100.0 73.1 33.3 100.0 100.0 4.9 89.2
Tree/Simple/Visitor/LoadDirectoryTree.pm 100.0 89.3 85.2 100.0 100.0 26.1 94.7
Tree/Simple/Visitor/FindByNodeValue.pm 100.0 100.0 86.7 100.0 100.0 3.1 98.3
Tree/Simple/Visitor/FindByPath.pm 100.0 100.0 66.7 100.0 100.0 1.2 97.9
Tree/Simple/Visitor/FindByUID.pm 100.0 100.0 86.7 100.0 100.0 2.9 98.3
Tree/Simple/Visitor/GetAllDescendents.pm 100.0 100.0 77.8 100.0 100.0 2.3 97.1
Tree/Simple/Visitor/PathToRoot.pm 100.0 87.5 75.0 100.0 100.0 0.8 95.1
Tree/Simple/Visitor/Sort.pm 100.0 100.0 77.8 100.0 100.0 8.8 98.1
Tree/Simple/Visitor/ToNestedArray.pm 100.0 100.0 66.7 100.0 100.0 1.5 96.5
Tree/Simple/Visitor/ToNestedHash.pm 100.0 100.0 66.7 100.0 100.0 1.4 96.5
Tree/Simple/Visitor/FromNestedArray.pm 100.0 94.4 81.8 100.0 100.0 8.1 96.6
Tree/Simple/Visitor/FromNestedHash.pm 100.0 91.7 77.8 100.0 100.0 4.8 95.9
Tree/Simple/Visitor/VariableDepthClone.pm 100.0 100.0 66.7 100.0 100.0 25.5 97.3
-------------------------------------------- ------ ------ ------ ------ ------ ------ ------
Total 100.0 93.8 76.3 100.0 100.0 100.0 96.1
-------------------------------------------- ------ ------ ------ ------ ------ ------ ------
SEE ALSO¶
These Visitor classes are meant to work with Tree::Simple hierarchies, you
should refer to that module for more information.
AUTHOR¶
stevan little, <stevan@iinteractive.com>
Ron Savage <ron@savage.net.au> has taken over maintenance as of V 0.11.
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.