... Mason directive that defines one component from within another. The component embedded within the <%def> block is called a subcomponent , and it is visible only to the component within ... request. Now imagine another scenario, one in which the method needs to examine the incoming arguments in order to generate its output. For instance, suppose you request /view_user .html? id=2982, ... in Perl& apos;s eval {} block, and check $@ after the method call. Sharing Data Among Component Sections By default, the scope of variables created within an <%init> block, a Perl line,...