Lazy enumerator to handle huge files

Lazy evaluation, or call-by-need is an evaluation strategy which delays the evaluation of an expression until its value is needed. It’s frequently seen in functional languages, ruby introduced the lazy method in Ruby 2.0. For those who don’t know what are enumerators: enumerators are something that can be counted. So a collection of elements, files (file…

after_create vs after_save vs after_commit

after_save, after_create and after_commit are called active record call backs in rails. They get executed when we work on the database, similarly we also have before_* callback and callbacks on destroy as well. In this article I will explain you about the difference between *_save, *_create and *_commit callbacks. The purpose of each as per…