my %sub_components = (
	default_page     => 'defaultpage.comp'
	full_text_search => 'fulltextsearch.comp',
	filename_search  => 'filenamesearch.comp',
	view_alignment   => 'viewalignment.comp',
	add_folder       => 'addfolder.comp'
	...
);

if ($op) {
	if (exists $sub_components{$op}) {
		# execute the appropriate sub-component:
		eval { $m->comp($sub_components{$op}, %ARGS) };

		if ($@) {
			# handle die() from the sub-component...
		}
	}
	else {
		# handle a request with "op" set to an invalid operation...
	}
}

...

<%args>
$op => 'default_page'
</%args>