It looks like you have some sort of event-driven architecture. My first instinct is to use callbacks. Something like:

my %callbacks = (
    foo => \&do_foo,
    bar => \&do_bar,
etc ...
);

my $action = $cgi->param('action');

my $callback = $callbacks{$action};

die "No callback!\n" unless $callback;

return $callback->(@args);
[download]

Then, you work some neat mechanism of registering the callbacks. They can even be the result of can (but you have to have an appropriate object to call it on) or method names (to be called on appropriate objects, presumably with can).

Of course, using CGI::Application is good cause it encapsulates the annoying work for you. :-)

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Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.