Tk::ConfigSpecs is a Perl module that defines the behavior of 'configure' for composite widgets.
my ($composite,$args) = @_;
$composite->ConfigSpecs('-attribute' => [ where,dbName,dbClass,default ]);
$composite->ConfigSpecs('-alias' => '-otherattribute');
$composite->ConfigSpecs('DEFAULT' => [ where ]);
$composite->configure(-attribute => value);
The aim is to make the composite widget configure method look as much like a regular Tk widget's configure as possible. (See Tk::options for a description of this behaviour.) To enable this the attributes that the composite as a whole accepts needs to be defined.