This book describes metaprogramming as an essential component of Ruby. Each page in the chapter has some introduction, a new concept, an exercise to try out, some more concepts with exercises and wrapping it up by using all the elements learned in that chapter in a slightly challenging exercise. :-D. Ruby Metaprogramming Study Note Try to hack the Sample Apps! Trying to define a 'class' without using 'class' sentence, class_variables (Try it out: instance_variables), instance_variable_set (Try it out: instance_variable_get), class Dog has three methods: initialize, can, method_missing, may be useful to define the static data like this: I'd like to add the count feature without editing the original file. MSGS = {:dance => 'is dancing', :poo => 'is a smelly doggy! MetaProgramming - Extending Ruby for Fun and Profit. It’s not unusal to hear people complaining about ‘black magic’ in Ruby codebases. Exercise 1: Get the values from outside the class. There are three dogs named Lassie, Fido and Stimpy. The product team has a great new feature they want to add to your Ruby on Rails application: they … It's awesome and fun! We can get the AST of any Elixir code using the quote/2 macro: Unlike the callbacks associated with methods where the parameter is a Symbol, here we receive the actual object representing the Class/Module. I would very much like to evangelize and enfuse in others this passion for ruby. Let’s re-write the program, adding the method to the class by re-opening it. There are three dogs named Lassie, Fido and Stimpy. Thus, this Ruby programming language book has chosen a hard way to teach the readers. ... building your credentials by completing exercises, activities and assessment checks. I've been working with ruby for half a decade and am trully in love with how elegant the code is. Look at dog_game.rb. There are several levels – Ruby Primer, Ruby Primer: Ascent, Metaprogramming Ruby and Metaprogramming Ruby: Ascent. Metaprogramming. I'd like to highly recommend this book. Each page in the chapter has some introduction, a new concept, an exercise to try out, some more concepts with exercises and wrapping it up by using all the elements learned in that chapter in a slightly challenging exercise. Most makefiles provide a target called clean. The 5-day Ruby on Rails Programming class led by Sang Shin has been great. The book also includes a long and thorough introduction to the rich API of the Ruby platform, demonstrating with heavily-commented example code. Think of it as a way to “undo” all of the build steps. Learning metaprogramming doesn't have to be difficult or boring. Let's add a method called words to String to do just this. Here are some things you can do with metaprogramming in the Ruby language: • Say you want to write a Ruby program that connects to an external system —maybe a web service or a Java program. No need to wait for the scheduled class. The courses are for various types of learners; beginner, intermediate as well as advanced and professional learners. GitHub is where people build software. The book covers a lot of core Ruby concepts that are critical to understand metaprogramming: Ruby's object model, method lookup, and module. Exercises ¶ ↑ Metaprogramming … at runtime. • Ruby’s object model is the land in which metaprogramming lives. Start writing elegant Ruby & Rails code and understanding all the magic behind Ruby on Rails.. If you’ve done Ruby programming before, this course will help take your coding to the next level. Practicing with ruby metaprogramming can deepen your understaning of how ruby works 'under the hood', which in turn will help you think through solving 'regular' problems more effectively. Metaprogramming "spells"--34 practical recipes and idioms that you can study and apply right now, to write code that is sure to impress. Metaprogramming Ruby Ruby Object Model. Metaprogramming is code that writes code. Exercise … Metaprogramming means writing code that writes code. In ruby … Expected output is the following:. Also you can do some Ruby … In this vast book, there are a lot of exercises that include setup exercise, comment, and puns, character exercise, … Practice metaprogramming in ruby with the Ruby Metaprogramming … The Ruby Object Model - Dave Thomas' presentation at Scotland on Rails. Metaprogramming Ruby. Exercises But first let’s finish the homework (day 3 has only a short one). Ruby Metaprogramming – Complete Course. This chapter introduces you to the most basic metaprogramming tech-niques. Ruby also has callbacks to track methods marked "undefined" with the rarely used undef_method. Press J to jump to the feed. One can add create a … From here, we edit the input to test to see if we have template injection. Tag: ruby. Based on the <%= syntax and the use of other Ruby technologies in the application, we can guess this might be Ruby/ERB. The focus of this book is to demonstrate how metaprogramming happens in Ruby, what its limitations are and what kinds of problems are best solved using it. It contains 30 Ruby courses and tutorials from among a pool of highest ranked ones. Expected output is the following: Look at dog_game.rb. Ruby has several metaprogramming facilities. Implement a clean target for the paper.pdf Makefile above. I've been working with ruby for half a decade and am trully in love with how elegant the code is. Whether you're a Ruby apprentice on the path to mastering the language or a Ruby wiz in search of new tips, this book is for you. 66.9k members in the ruby community. Based on the <%= syntax and the use of other Ruby technologies in the application, we can guess this might be Ruby/ERB. As with all our lessons, we believe that the best way to learn is by doing. There are a number of additions to the standard library, including: Exercises. - Quote from The Ruby Object Model. Could you please complete it? This means it is able to create methods and classes dynamically. Try to do the following exercises. The alternative is to generate a method definition as a string and execute the string as Ruby code. Exercise 1.02: Assigning a Variable of One Data Type to a Different Type. Level up your Ruby skills on your own schedule. Chapter 2, Monday: The Object Model, on page ?, provides a map to this land. It means that a program can be designed to read, generate, analyze or … Grab over 4 hours of video teaching the power of Ruby's metaprogramming and watch it whenever you want. Module.included receives just one parameter, which is the Module or Class into which your Module was included. In the example below, here are some of the "meta" changes we're making to the program: The end result is the ability to combine the elements of any array containing any type of object in fairly arbitrary ways. The course has a good balance of interactive lectures and hands-on exercises. Once the foundation is laid, basic metaprogramming … Press question mark to learn the rest of the keyboard shortcuts ... Log in sign up. Pragmatic Programmers. Interactive Ruby Shell. Launch School’s Ruby Small Problems. complex programming exercises with higher motivational value from very early on. This fails, obviously, because there’s no method called everything_changes. Expected output is the following: Try to write your own alias_method_chain(). Read _why's hacking, Seeing Metaclasses Clearly to learn about the following singleton class (metaclass), Read Marc-Andre Cournoyer's blog, Extending your include knowledge of Ruby to learn about the following methods. Once the foundation is laid, basic metaprogramming concepts like define_method and method_missing are covered. The callbacks match the ones for removed methods and are called method_undefined and singleton_method_undefined. For free! The book is packed with: Pragmatic examples of metaprogramming in action, many of which come straight from real-life gems such as Rails. I'm starting to learn metaprogramming in Ruby and (I think) I'm understanding how to add instance methods and variables, but only if passed in one at a time. # metakoans.rb is an arduous set of exercises designed to stretch # meta-programming muscle. Look at this simple example from Metaprogramming Ruby. Experience dynamic power. Ruby caught my attention due to its idiomatic constructs and powerful metaprogramming capabilities. ... Perrotta, P. (20 10) Metaprogramming Ruby. Metaprogramming Ruby, Second Edition makes mastering the language enjoyable. You can do without editing original code! Ruby 2.0 is a minor update to Ruby 1.9, unlike the more major updates from Ruby 1.8 to Ruby 1.9. Exercise … These may be useful for programmers who have turned to Ruby from other languages or have not yet experienced the joys of Ruby metaprogramming. Note: If you have an idea in your mind. Ruby and in Rails. Learn the most important part of Ruby that makes Rails possible and then leverage the power of Rails. Code that writes code. I’ll start by stating the obvious: you should first and foremost do the Ruby Small Problems provided by Launch School. You can do all of your metaprogramming with define_method, but the code doesn't look a lot like the code you'd write in normal programming. What a gem. Ruby's String has no method that allows you to split a sentence into an Array of words. Learning when metaprogramming is the right tool for the job will be of considerable value to you in creating powerful yet maintainable codebases. Go beyond the basics of coding with Rails, instead make Rails work extra hard for you. Ruby provides the Module.included method to receive callbacks when this happens. Run with ruby … The second element is a list of metadata (often line numbers when read from a file). Use a single case class using the Singleton-class. Feel free to please show us and try to do that. More than 50 million people use GitHub to discover, fork, and contribute to over 100 million projects. The course has a good balance of interactive lectures and hands-on exercises… Now suppose you want to wrap logging behavior around the above greet(). Watch the Dave Thomas's presentation about Metaprogramming. Class Method to 'Know' Class Name in Ruby? I wrote the following code. Metaprogramming is supported across many languages using many different techniques; you’ve probably used some of them already. You can add methods to classes, remove them or redefine them. From here, we edit the input to test to see if we have template injection. Programming challenges that let you experiment and play with some of the most out-there metaprogramming concepts. Advanced Ruby: a 2nd level course. Metaprogramming is writing programs that write programs. Drawbacks to Metaprogramming. I have been auditing the class all week thanks to Sang placing a notice on the SF Ruby meetup list and have learned a … Reas, C. and Fr y, B. Details are here. Contribute to LouisKottmann/metaprogramming-ruby development by creating an account on GitHub. Books ¶ ↑ Metaprogramming Ruby - Entire book. I really advice to read a book "Metaprogramming in Ruby" by Paolo Perotta (reference in the link above). If you are curious, join the Ruby Metaprogramming course on RubyLearning. This last is pretty important, because metaprogramming is arguably one of the most misused features of the Ruby … This is usually because they, or the author of that codebase, or both didn’t understand metaprogramming. With the help of this course you can Learn metaprogramming! ;-), Okay, let's discuss your code in the relevant thread in the Second Week Forum. This isn’t intended to produce a file called clean, but instead to clean up any files that can be re-built by make. I'm Table of contents We'll cover it for completeness, but don't expect to see or use this very often. On an important note, you should make sure to use metaprogramming with caution. For example, when a User model is defined in Rails with email as an attribute, a method called find_by_email will be generated. Read the following article: 3rd, review the scope of variables. Learn the most important part of Ruby that makes Rails possible and then leverage the power of Rails. Ruby 2.0 is a minor update to Ruby 1.9, unlike the more major updates from Ruby 1.8 to Ruby 1.9. In Ruby, a class is simply an object like … Ruby as a really powerful set of tools for metaprogramming, but a good understanding of Ruby’s metamodel and some of its darker corners is required to fully benefit from them. The first element of the tuple may be an atom or another tuple. Watch the following presentation, the Scotland on Rails conference 2009, by Dave Thomas. Let's start learning Ruby Metaprogramming! This means it is able to create methods and classes dynamically. There are several levels – Ruby Primer, Ruby Primer: Ascent, Metaprogramming Ruby and Metaprogramming Ruby… There are several levels – Ruby Primer, Ruby Primer: Ascent, Metaprogramming Ruby and Metaprogramming Ruby… The major language changes in Ruby 2.0 are the addition of keyword arguments and the change to use … Good metaprogramming. It's very easy to extend and modify existing primitives at runtime. Once you’re done, you should also re-do them at least once. Also read Ruby-Doc Core API: Module#included and Module#extended. It's awesome and fun! Go beyond the basics of coding with Rails, instead make Rails work extra hard for you. This involves inspecting and modifying a program as it runs using constructs exposed by the language. Metaprogramming is the act of writing code that operates on code rather than on data. In this book, you'll learn metaprogramming as an essential component of Ruby and discover the deep, non-obvious details of the language. An entire chapter is devoted to Ruby's metaprogramming capabilities. :-D. This page was last updated on 20th Dec. 2009. Ruby caught my attention due to its idiomatic constructs and powerful metaprogramming capabilities. This is fairly unusual for a mainstream object oriented language. Ruby supports metaprogramming, which is a technique that helps you to write code that creates code on its own. You can't set an instance variable with @foo=4; you have to call instance_variable_set('foo', 4). Exercise 2: Add your code to display 'I like metaprogramming!' The major language changes in Ruby 2.0 are the addition of keyword arguments and the change to use UTF-8 as the default source file encoding. For example, test.new_value = true. Ability to create classes, methods, functions, etc. This course was created by Said Abduvaliev. With … It explains some of the more advanced features of Ruby including blocks and processes, threads, regular expressions, exception handling, singletons, and metaprogramming. Exercise 4: Glance into Ruby inside with binding method. This gives it more flexibility and is considered one of the most critical aspects to implementing metaprogramming in Ruby. Ruby on Rails is a framework where code can do the exact same thing but look so very different, which can make it hard to maintain a project, especially across a development team where multiple individuals are contributing. Let's discuss all these exercises in the Metaprogramming Ruby thread in the First Week Forum. ', :laugh => 'finds this hilarious! Its creator, Yukihiro “Matz” Matsumoto , blended parts of his favorite languages (Perl, Smalltalk, Eiffel, Ada, and Lisp) to form a new language that balanced functional programming with imperative programming. This last is pretty important, because metaprogramming is arguably one of the most misused features of the Ruby language. MetaProgramming - Extending Ruby for Fun and Profit - Dave Thomas' presentation at QCon. It also reveals the secrets behind Ruby classes and method lookup, the process by which Ruby finds and executes methods. Practice metaprogramming in ruby with the Ruby Metaprogramming Koans. Ruby's facilities for text processing, numeric manipulation, collections, input/output, networking, and concurrency. A complete Ruby tutorial with exercises and activities that help build key skills Structured to let you progress at your own pace, on your own terms Use your physical copy to redeem free access to the online interactive edition; Book Description. This allows us to modify the behavior of a program at run time. Just me doing metaprogramming exercises. With metaprogramming, you … The book is packed with: Pragmatic examples of metaprogramming in action, many of which come straight from real-life gems such as Rails. advanced Metaprogramming Ruby: Ascent. Through the years I’ve witnessed many metaprogramming … Start Course. You already know you want to learn Ruby, and the smarter way to learn Ruby 2.X is to learn by doing. Please refer our accompanying study notes and examples. First of all, things like [] (array index) and []= are just methods in Ruby… You'll learn from real examples that lead to real results. Ruby was created as a language of careful balance. Useful as a quick reference. Instructions. The book covers a lot of core Ruby concepts that are critical to understand metaprogramming: Ruby's object model, method lookup, and module. I had a chance to look at what Neal Ford had to write on Fluent Interfaces in his book The Productive Programmer.. Granted, I heard him cover it … Of a program at run time to implementing metaprogramming in Ruby i really to., Udacity, Ruby-Doc, learn Ruby, chapter 20: Dynamic programming Ruby... Of 5 by approx 12209 ratings it whenever you want ruby metaprogramming exercises to learn the most part... To please Show us and Try to do just this dig under the surface and explore 's! It 's very easy to extend and modify existing primitives at runtime which metaprogramming lives discover the,... Module or class into which your Module was included ’ ve witnessed many metaprogramming … define_method Ruby. Technique that helps you to the most out-there metaprogramming concepts also reveals secrets... These aliases all around, let 's provide alias_method_chain ( ) that metaprogramming. A Variable of one Data Type to a Different Type, but n't.: a collection of techniques and tricks known as metaprogramming and assessment checks … Ruby supports,... 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On its own Ruby ’ s object Model and metaprogramming Ruby… Ruby send method,,... ( day 3 has only a short one ) Programmers who have to. Programming exercises with higher motivational value from very early on completeness, do... When this happens the built-in, read-only Variable self Rails code and exercises and a copy of Ruby techniques! Build steps understand metaprogramming 've been working with Ruby metaprogramming class is simply an object like the! Show us and Try to hack the Sample code and Data, Lisp style is an..., learn Ruby, Second Edition makes mastering the language enjoyable Ruby Shell explore Ruby 's for... To wrap logging behavior around the above greet ( ) generate a method called find_by_email be. Programming before, ruby metaprogramming exercises course will help take your coding to the rich of. To classes, remove them or redefine them three dogs named Lassie, Fido and Stimpy critical aspects implementing. This: instead of duplicating these aliases all around, let 's a! Across many languages using many Different techniques ; you ’ re done, should! 20: Dynamic programming this book, you should first and foremost do Ruby... ; - ), Okay, let 's practice how to build your practical Ruby skills so that can. Make sure to use metaprogramming with caution code with code in the relevant in. With the rarely used undef_method this very often people use GitHub to discover,,! Advanced feature: a collection of techniques and tricks known as metaprogramming behind Ruby on Rails activities. Highest ranked ones and many more, functions, etc power of.. And classes dynamically program, adding the method to 'Know ' class Name in Ruby 2. Variable self a language of careful balance has callbacks to track methods ``! A technique that helps you to the next level courses and tutorials from among a of.