In CGI::Application-based applications, it's often handy to have a module that mixes-in methods into a primary module, which simply means that the methods are added using standard "has a" export/import techniques. That's what a number of the C::A plugins do.
There is a sticking point though. The mix-in may want to call an internal method, as:
$self->_internal_method(@args)
However, the way the OO works, this method is expected in the package that has been mixed into, although you don't want to export it there.
Cees Hek pointed out a simple solution to this, which I managed to miss for several years:
_internal_method($self,@args);Passing in $self like that keeps the method internal to the mix-in as desired.
