Our application is looking great. However the navigation elements have quite a bit of duplicate code, which violates a core Rails development practice. In this guide we'll walk through how to build a view helper method that dynamically generates the navigation bar based on which page is being viewed. Additionally, we'll build a helper method that adds the `active` status to navigation elements when a user is on a specific page.

In this deep dive we're going to analyze how the Rails 5 asset pipeline works. Specifically, we're going to discuss: minification, caching, and the difference between the Rails development and production modes.