The Template pattern is one of those widely used patterns that are incredibly useful, especially when writing libraries and frameworks. The idea is to provide a user some way to execute code within an algorithm.
In this section, we will see how to write idiomatic Go Template patterns and see some Go source code where it's wisely used. We will write an algorithm of three steps where the second step is delegated to the user while the first and third aren't. The first and third steps on the algorithm represent the template.
While with the Strategy pattern we were encapsulating algorithm implementation in different strategies, with the Template pattern we will try to achieve something similar but with just part of the algorithm.
The Template design pattern lets the user write a part of an algorithm while the rest is executed by the abstraction. This is common when creating libraries to ease in some complex task or when reusability of some algorithm is compromised...