Use cases

The Template design pattern focuses on eliminating code repetition. If we notice that there is repeatable code in algorithms that have structural similarities, we can keep the invariant (common) parts of the algorithms in a template method/function and move the variant (different) parts in action/hook methods/functions.

Pagination is a good use case to use Template. A pagination algorithm can be split into an abstract (invariant) part and a concrete (variant) part. The invariant part takes care of things such as the maximum number of lines/page. The variant part contains functionality to show the header and footer of a specific page that is paginated [j.mp/templatemart, page 10].

All application frameworks make use of some form of the Template pattern. When we use a framework to create a graphical application, we usually inherit from a class and implement our custom behavior. However, before this, a Template method is usually called that implements the part of the application that...