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 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.
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.
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.