LoadClassHierarchy.pm [plain text]
package Tree::Simple::Visitor::LoadClassHierarchy;
use strict;
use warnings;
our $VERSION = '0.02';
use Scalar::Util qw(blessed);
use base qw(Tree::Simple::Visitor);
sub new {
my ($_class) = @_;
my $class = ref($_class) || $_class;
my $visitor = {};
bless($visitor, $class);
$visitor->_init();
return $visitor;
}
sub _init {
my ($self) = @_;
$self->{class_to_load} = undef;
$self->{include_methods} = 0;
$self->SUPER::_init();
}
sub setClass {
my ($self, $class_to_load) = @_;
(defined($class_to_load)) || die "Insufficient Arguments : Must provide a class to load";
$self->{class_to_load} = $class_to_load;
}
sub includeMethods {
my ($self, $boolean) = @_;
$self->{include_methods} = ($boolean ? 1 : 0) if defined $boolean;
return $self->{include_methods};
}
sub visit {
my ($self, $tree) = @_;
(blessed($tree) && $tree->isa("Tree::Simple"))
|| die "Insufficient Arguments : You must supply a valid Tree::Simple object";
($tree->isLeaf()) || die "Illegal Operation : The tree must be a leaf node to load a class hierarchy";
(defined $self->{class_to_load}) || die "Insufficient Arguments : Must provide a class to load";
my $filter = $self->getNodeFilter();
my $class_to_load = ref($self->{class_to_load}) || $self->{class_to_load};
if ($self->includeTrunk()) {
$tree->setNodeValue(defined $filter ? $filter->($class_to_load) : $class_to_load);
}
else {
my $new_tree = Tree::Simple->new(defined $filter ? $filter->($class_to_load) : $class_to_load);
$tree->addChild($new_tree);
if ($self->includeMethods()) {
$self->_loadMethods($new_tree, $class_to_load, $filter);
}
$tree = $new_tree;
}
$self->_loadClass($tree, $class_to_load, $filter);
}
sub _loadClass {
my ($self, $tree, $class_to_load, $filter) = @_;
my @superclasses;
{
no strict 'refs';
@superclasses = @{"${class_to_load}::ISA"};
}
foreach my $superclass (@superclasses) {
my $new_tree = Tree::Simple->new(defined $filter ? $filter->($superclass) : $superclass);
$tree->addChild($new_tree);
if ($self->includeMethods()) {
$self->_loadMethods($new_tree, $superclass, $filter);
}
$self->_loadClass($new_tree, $superclass, $filter);
}
}
sub _loadMethods {
my ($self, $tree, $class, $filter) = @_;
my @methods;
{
no strict 'refs';
@methods = sort grep { defined &{"${class}::$_"} } keys %{"${class}::"};
}
foreach my $method (@methods) {
$tree->addChild(Tree::Simple->new(defined $filter ? $filter->($method) : $method));
}
}
1;
__END__
=head1 NAME
Tree::Simple::Visitor::LoadClassHierarchy - A Visitor for loading class hierarchies into a Tree::Simple hierarchy
=head1 SYNOPSIS
use Tree::Simple::Visitor::LoadClassHierarchy;
# create an visitor
my $visitor = Tree::Simple::Visitor::LoadClassHierarchy->new();
# set class as an instance, or
$visitor->setClass($class);
# as a package name
$visitor->setClass("My::Class");
# pass our visitor to the tree
$tree->accept($visitor);
# the $tree now mirrors the inheritance hierarchy of the $class
=head1 DESCRIPTION
This visitor will traverse a class's inheritance hierarchy (through the @ISA arrays) and create a Tree::Simple hierarchy which mirrors it.
=head1 METHODS
=over 4
=item B<new>
There are no arguments to the constructor the object will be in its default state. You can use the C<setNodeFilter> method to customize its behavior.
=item B<includeTrunk ($boolean)>
Setting the C<$boolean> value to true (C<1>) will cause the node value of the C<$tree> object passed into C<visit> to be set with the root value found in the class heirarchy. Setting it to false (C<0>), or not setting it, will result in the first value in the class heirarchy creating a new node level.
=item B<includeMethods ($boolean)>
Setting the C<$boolean> value to true (C<1>) will cause methods to be added as a children of the class node. Setting it to false (C<0>), or not setting it, will result in this not happening.
B<NOTE:> Methods are sorted ascii-betically before they are added to the tree. This allows a more predictable heirarchy.
=item B<setClass ($class)>
The argument C<$class> should be either a class name or an instance, it is then used as the root from which to determine the class hierarchy.
=item B<setNodeFilter ($filter_function)>
This method accepts a CODE reference as its C<$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 C<$filter_function> is passed the node value extracted from the hash prior to it being inserted into the tree being built. The C<$filter_function> is expected to return the value desired for inclusion into the tree.
=item B<visit ($tree)>
This is the method that is used by Tree::Simple's C<accept> method. It can also be used on its own, it requires the C<$tree> argument to be a Tree::Simple object (or derived from a Tree::Simple object), and will throw and exception otherwise.
The C<$tree> argument which is passed to C<visit> must be a leaf node. This is because this Visitor will create all the sub-nodes for this tree. If the tree is not a leaf, an exception is thrown. We do not require the tree to be a root though, and this Visitor will not affect any nodes above the C<$tree> argument.
=back
=head1 TO DO
=over
=item Improve the C<includeMethods> functionality
I am not sure the tree this creates is the optimal tree for this situation. It is sufficient for now, until I have more of an I<actual> need for this functionality.
=item Add C<includeFullSymbolTable> functionality
This would traverse the full symbol tables and produce a detailed tree of everything it finds. This takes a lot more work, and as I have no current need for it, it remains in the TO DO list.
=back
=head1 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.
=head1 CODE COVERAGE
See the B<CODE COVERAGE> section in L<Tree::Simple::VisitorFactory> for more inforamtion.
=head1 SEE ALSO
These Visitor classes are all subclasses of B<Tree::Simple::Visitor>, which can be found in the B<Tree::Simple> module, you should refer to that module for more information.
=head1 AUTHOR
stevan little, E<lt>stevan@iinteractive.comE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright 2004, 2005 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut