--- /dev/null
+# vim: ts=8:sw=4:sts=4:et
+package DBIx::Class::Tree::AdjacencyList::Positional;
+use strict;
+use warnings;
+use base qw( DBIx::Class );
+use Carp qw( croak );
+
+__PACKAGE__->load_components(qw(
+ Tree::AdjacencyList
+ Positional
+));
+
+=head1 NAME
+
+DBIx::Class::Tree::AdjacencyList::Positional - Glue DBIx::Class::Positional and DBIx::Class::Tree::AdjacencyList together. (EXPERIMENTAL)
+
+=head1 SYNOPSIS
+
+Create a table for your tree data.
+
+ CREATE TABLE employees (
+ employee_id INTEGER PRIMARY KEY AUTOINCREMENT,
+ parent_id INTEGER NOT NULL,
+ position INTEGER NOT NULL,
+ name TEXT NOT NULL
+ );
+
+In your Schema or DB class add Tree::AdjacencyList::Positional
+to the top of the component list.
+
+ __PACKAGE__->load_components(qw( Tree::AdjacencyList::Positional ... ));
+
+Specify the column that contains the parent ID and position of each row.
+
+ package My::Employee;
+ __PACKAGE__->parent_column('parent_id');
+ __PACAKGE__->position_column('position');
+
+This module provides a few extra methods beyond what
+L<DBIx::Class::Positional> and L<DBIx::Class::Tree::AdjacencyList>
+already provide.
+
+ my $parent = $employee->parent();
+ $employee->parent( $parent_obj );
+ $employee->parent( $parent_id );
+
+ my $children_rs = $employee->children();
+ my @children = $employee->children();
+
+ $parent->append_child( $child );
+ $parent->prepend_child( $child );
+
+ $this->attach_before( $that );
+ $this->attach_after( $that );
+
+=head1 DESCRIPTION
+
+This module provides methods for working with adjacency lists and positional
+rows. All of the methods that L<DBIx::Class::Positional> and
+L<DBIx::Class::Tree::AdjacencyList> provide are available with this module.
+If you
+
+=head1 METHODS
+
+=head2 parent
+
+ my $parent = $employee->parent();
+ $employee->parent( $parent_obj );
+ $employee->parent( $parent_id );
+
+ my $children_rs = $employee->children();
+ my @children = $employee->children();
+
+This method works exactly like it does in the
+DBIx::Class::Tree::AdjacencyList module except that it will
+first move the object to the last position of the list, change
+the parent ID, then move the object to the last position of
+the new list. This ensures the intergrity of the positions.
+
+=cut
+
+sub parent {
+ my( $self, $new_parent ) = @_;
+ if ($new_parent) {
+ if (ref($new_parent)) {
+ $new_parent = $new_parent->id() || 0;
+ }
+ return 0 if ($new_parent == ($self->get_column($self->parent_column())||0));
+ $self->move_last();
+ return 0 if (!$self->next::method( $new_parent ));
+ $self->set_column(
+ $self->position_column() => $self->search( {$self->_collection_clause()} )->count() + 1
+ );
+ $self->update();
+ return 1;
+ }
+ else {
+ return $self->next::method();
+ }
+}
+
+=head2 children
+
+ my $children_rs = $employee->children();
+ my @children = $employee->children();
+
+This method works just like it does in the
+DBIx::Class::Tree::AdjacencyList module except it
+orders the children by there position.
+
+=cut
+
+sub children {
+ my( $self ) = @_;
+ my $rs = $self->search(
+ { $self->parent_column() => $self->id() },
+ { order_by => $self->position_column() }
+ );
+ return $rs->all() if (wantarray());
+ return $rs;
+}
+
+=head2 append_child
+
+ $parent->append_child( $child );
+
+Sets the child to have the specified parent and moves the
+child to the last position.
+
+=cut
+
+sub append_child {
+ my( $self, $child ) = @_;
+ $child->parent( $self );
+}
+
+=head2 prepend_child
+
+ $parent->prepend_child( $child );
+
+Sets the child to have the specified parent and moves the
+child to the first position.
+
+=cut
+
+sub prepend_child {
+ my( $self, $child ) = @_;
+ $child->parent( $self );
+ $child->move_first();
+}
+
+=head2 attach_before
+
+ $this->attach_before( $that );
+
+Attaches the object at the position just before the
+calling object's position.
+
+=cut
+
+sub attach_before {
+ my( $self, $sibling ) = @_;
+ $sibling->parent( $self->parent() );
+ $sibling->move_to( $self->get_column($self->position_column()) );
+}
+
+=head2 attach_after
+
+ $this->attach_after( $that );
+
+Attaches the object at the position just after the
+calling object's position.
+
+=cut
+
+sub attach_after {
+ my( $self, $sibling ) = @_;
+ $sibling->parent( $self->parent() );
+ $sibling->move_to( $self->get_column($self->position_column()) + 1 );
+}
+
+=head1 PRIVATE METHODS
+
+These methods are used internally. You should never have the
+need to use them.
+
+=head2 _collection_clause
+
+This method is provided as an override of the method in
+L<DBIx::Class::Positional>. This method is what provides the
+glue between AdjacencyList and Positional.
+
+=cut
+
+sub _collection_clause {
+ my( $self ) = @_;
+ return (
+ $self->parent_column() =>
+ $self->get_column($self->parent_column())
+ );
+}
+
+1;
+__END__
+
+=head1 AUTHOR
+
+Aran Clary Deltac <bluefeet@cpan.org>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+