It is a system of economic analysis based upon praxeology and causal-realism. The Austrian school recognizes that economic analysis is timeless and the ancient story of “The Poor Man of Nippur” ...
These food trackers can help you follow a healthy eating plan, teach you to make smarter food choices and assist in weight loss – plus, most of them are free.
That said, an example might help you get going. Have a look at this sample of a Ruby on Rails model (be aware that this is truncated, not working code): The Code Smells docs may give you further hints ...