|How can you change your application from this...|
EDIT: Thanks to Action Dan for some feedback that picks into the niche differences of web application frameworks.
Bear in mind this is a Rails specific post, but I will say that for purposes of building larger applications, the ability to organize and refactor code begins to become a problem.
Rails also offers uniform ways to add and remove helper functions through package management, so I'm actually using the current_user function generated by adding the Clearance gem to my project.
The simple markup syntax is one small reason people like using Ruby on Rails to develop web applications.
Using a helper function (that I didn't even have to write) are two "behind the scenes" benefits of using Rails to develop.
If your confused about the current_user helper I'm using, read more here.