table of contents
Tree::Simple::Visitor::LoadDirectoryTree(3pm) | User Contributed Perl Documentation | Tree::Simple::Visitor::LoadDirectoryTree(3pm) |
NAME¶
Tree::Simple::Visitor::LoadDirectoryTree - A Visitor for loading the contents of a directory into a Tree::Simple object
SYNOPSIS¶
use Tree::Simple::Visitor::LoadDirectoryTree; # create a Tree::Simple object whose # node is path to a directory my $tree = Tree::Simple->new("./"); # create an instance of our visitor my $visitor = Tree::Simple::Visitor::LoadDirectoryTree->new(); # set the directory sorting style $visitor->setSortStyle($visitor->SORT_FILES_FIRST); # create node filter to filter # out certain files and directories $visitor->setNodeFilter(sub { my ($item) = @_; return 0 if $item =~ /CVS/; return 1; }); # pass the visitor to a Tree::Simple object $tree->accept($visitor); # the tree now mirrors the structure of the directory
DESCRIPTION¶
This visitor can be used to load a directory tree into a Tree::Simple hierarchy.
METHODS¶
- new
- There are no arguments to the constructor the object will be in its default state. You can use the "setNodeFilter" and "setSortStyle" methods to customize its behavior.
- setNodeFilter ($filter_function)
- This method accepts a CODE reference as its $filter_function argument and throws an exception if it is not a code reference. This code reference is used to filter the tree nodes as they are created. The function is given the current directory or file being added to the tree, and it is expected to return either true (1) of false (0) to determine if that directory should be traversed or file added to the tree.
- setSortStyle ($sort_function)
- This method accepts a CODE reference as its
$sort_function argument and throws an exception if
it is not a code reference. This function is used to sort the individual
levels of the directory tree right before it is added to the tree being
built. The function is passed the current path, followed by the two items
being sorted. The reason for passing the path in is so that sorting
operations can be performed on the entire path if desired.
Two pre-built functions are supplied and described below.
- SORT_FILES_FIRST
- This sorting function will sort files before directories, so that files
are sorted alphabetically first in the list followed by directories sorted
alphabetically. Here is example of how that would look:
Tree/ Simple.pm Simple/ Visitor.pm VisitorFactory.pm Visitor/ PathToRoot.pm
- SORT_DIRS_FIRST
- This sorting function will sort directories before files, so that
directories are sorted alphabetically first in the list followed by files
sorted alphabetically. Here is example of how that would look:
Tree/ Simple/ Visitor/ PathToRoot.pm Visitor.pm VisitorFactory.pm Simple.pm
- visit ($tree)
- This is the method that is used by the Tree::Simple
"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.
The node value of the $tree argument (gotten by calling "getNodeValue") is considered the root directory from which we begin our traversal. We use File::Spec to keep our paths cross-platform, but it is expected that you will feed in a valid path for your OS. If the path either does not exist, or is not a directory, then an exception is thrown.
The $tree argument which is passed to "visit" must be a leaf node. This is because this Visitor will create all the sub-nodes for this tree. If the tree is not a leaf, an exception is thrown. We do not require the tree to be a root though, and this Visitor will not affect any nodes above the $tree argument.
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 |