work in progress, listview still broken

[catagits/Reaction.git] / lib / Reaction / InterfaceModel / Collection.pm

package Reaction::InterfaceModel::Collection;

use Reaction::Class;
use Scalar::Util qw/refaddr blessed/;
use aliased 'Reaction::Meta::InterfaceModel::Object::DomainModelAttribute';

# WARNING - DANGER: this is just an RFC, please DO NOT USE YET

class Collection is "Reaction::InterfaceModel::Object", which {

  # consider supporting slice, first, iterator, last etc.
  # pager functionality should probably be a role

  # IM objects don't have write methods because those are handled through actions,
  # no support for write actions either unless someone makes a good case for it
  # many models may not even be writable, so we cant make that assumption...

  # I feel like we should hasa result_class or object_class ?
  # having this here would remove a lot of PITA complexity from
  # ObjectClass and SchemaClass when it comes to munging with internals

  #Answer: No, because collections should be able to hold more than one type of object

  # ALL IMPLEMENTATIONS ARE TO ILLUSTRATE POSSIBLE BEHAVIOR ONLY. DON'T CONSIDER
  # THEM CORRECT, OR FINAL. JUST A ROUGH DRAFT.

  #domain_models are 'ro' unless otherwise specified
  has _collection_store => (
                            is  => 'rw',
                            isa => 'ArrayRef',
                            lazy_build => 1,
                            clearer    => "_clear_collection_store",
                            metaclass  => DomainModelAttribute,
                           );

  has 'member_type' => (is => 'ro', isa => 'ClassName');

  implements _build__collection_store => as { [] };

  implements members => as {
    my $self = shift;
    return @{ $self->_collection_store };
  };

  #return new member or it's index # ?
  implements add_member => as {
    my $self = shift;
    my $new  = shift;
    confess "Argument passed is not an object" unless blessed $new;
    confess "Object Passed does not meet constraint isa Reaction::InterfaceModel::Object"
      unless $new->isa('Reaction::InterfaceModel::Object');
    my $store = $self->_collection_store;
    push @$store, $new;
    return $#$store; #return index # of inserted item
  };

  implements remove_member => as {
    my $self = shift;
    my $rem = shift;
    confess "Argument passed is not an object" unless blessed $rem;
    confess "Object Passed does not meet constraint isa Reaction::InterfaceModel::Object"
      unless $rem->isa('Reaction::InterfaceModel::Object');

    my $addr = refaddr $rem;
    @{ $self->_collection_store } = grep {$addr ne refaddr $_ } @{ $self->_store };
  };

  #that was easy..
  implements count_members => sub{
    my $self = shift;
    return scalar @{ $self->_collection_store };
  };

};

1;

=head1 NAME

Reaction::InterfaceModel::Collection - Generic collections of
L<Reaction::InterfaceModel::Object>s

=head1 DESCRIPTION

The base class for C<InterfaceModel::Collection>s. The functionality implemented here
is minimal and it is expected that specialized collections be built by sublclassing
this and exploiting the roles system.

=head1 METHODS

=head2 members

Returns a list containing all known members of the collection

=head2 add_member $object

Will add the object passed to the collection

=head2 remove_member $object

Removed the object passed from the collection, if present

=head2 count_members

Returns the number of objects in the collection.

=head1 ATTRIBUTES

=head2 _collection_store

Read-write & lazy_build. Holds the arrayref where the collection of objects is
presently stored. Has a clearer of C<_clear_collection_store> and a predicate of
 C<_has_collection_store>.

=head1 PRIVATE METHODS

_build__collection_store

Builder method for attribute_collection_store, returns an empty arrayref

=head1 AUTHORS

See L<Reaction::Class> for authors.

=head1 LICENSE

See L<Reaction::Class> for the license.

=cut