Ruby Metaprogramming Examples

In the example below here are some of the meta changes we re making to the program.

Ruby metaprogramming examples.

For example when a user model is defined in rails with email as an attribute a method called find by email will be generated. 1st review the built in read only variable self. That s why in this article. Imagine that you have a database table for users that have columns such as name and email.

We re going to look at some popular open source projects using ruby metaprogramming. Metaprogramming is writing programs that write programs. Ruby is an interpreted high level general purpose programming language it was designed and developed in the mid 1990s by yukihiro matz matsumoto in japan. Metaprogramming is often presented as a very nebulous and dangerous concept one that is difficult to explain and hard.

Nov 20 th 2015 10 34 am. This involves inspecting and modifying a program as it runs using constructs exposed by the language. In ruby the term metaprogramming refers to the dynamic nature of the language which allows you to define and redefine methods and classes at runtime. In ruby the term metaprogramming refers to the dynamic nature of the language which allows you to define and redefine methods and classes at runtime.

Metaprogramming is the act of writing code that operates on code rather than on data. But it can be a bit confusing if you don t have a few specific examples. Ruby is dynamically typed and uses garbage collection it supports multiple programming paradigms including procedural object oriented and functional programming according to the creator ruby was influenced by perl smalltalk eiffel. Let s begin with a basic example.

Please refer our accompanying study notes and examples. When does self change. Examples of metaprogramming a basic example. It is because of this very feature that many gems such as rspec and activerecord can work the way they do.

Ruby metaprogramming one of the most interesting aspects of ruby enables the programming language to achieve an extreme level of expressiveness. Obviously the ruby on rails framework doesn t know what columns that you re going to have for the. Metaprogramming is often presented as a very nebulous and dangerous concept one that is difficult to explain and hard to wrap your head around and thus should be avoided. I m going to start with an example from the ruby on rails framework.

Self the current default object. All of them use some form of metaprogramming. You may have read about ruby metaprogramming before. Ruby metaprogramming by example.

Read the following articles. Quote from the ruby object model. In this article toptal engineer nikola todorovic demystifies. Let s start learning ruby metaprogramming.