Monkey patch class ruby

Due to rubys open classes you can redefine or add functionality to existing classes. Ruby is like a sharp knife, it can be extremely effective, but its usually your own fault if you cut yourself. Reopening code in this way is often known as monkey patching. In ruby, a monkey patch mp is any dynamic modification to a class and is often used as a synonym for dynamically modifying any class add new or overwrite existing. In ruby, the term monkey patch was misunderstood to mean any dynamic modification to a class and is often used as a synonym for dynamically modifying any class at runtime. This article looks at how to minimize the risk of opening classes, alternatives, and how other languages provide similar capabilities. Make monkey patching in ruby less risky with refinements.

In todays tutorial well be looking at monkey patching in ruby. Before i show you how to override a class, i want to ensure that you understand that monkeypatching. Lets create a hypothetical scenario in which i need to monkey patch the hash class. Ruby journal howtoopenslashoverrideslash monkeypatcha classin ruby. In ruby land, monkey patching is the act of modifying the methods on someone elses class. Ruby s open classes are powerful but can easily be misused. Rubys open classes are a useful feature that allows to add methods to an already loaded class, as simple as class string def foo. And that could lead to side effect if we are not careful. Honestly, i used to use the 1st form reopening the class, as it feels more natural, but your question forced me to do some research on the. Recommended approach to monkey patching a class in ruby stack. We can modify or extend any existing class at runtime, even built in classes like. In ruby, a monkey patch mp is any dynamic modification to a class and is often used as a synonym for dynamically modifying any class add new or overwrite existing methods at runtime. Rubys open classes are powerful but can easily be misused.

This just makes your monkey patches much more surefire. The above statement asserts that the ruby usage is incorrect but terms evolve, and thats not always a bad thing. How to monkey patch a class in ruby solid foundation web. Until you hit weird bugs because a patch changed hash. Yes thats right, you can actually reopen any class and change how it works. Use refinements to get fine grained control over your monkey patches. This includes the standard ruby classes like string, array or hash.

My reasoning is that ideally i should be able to see the functionality of a class from the class definition or through the inheritance chain and mixins used in the primary definition. Whats the deal with monkeypatching and why is everyone. So you search for how to moneykeypatch a class in ruby. Safer monkey patching in ruby thomas countz medium. Other forms of modifying classes at runtime have different names, based on their different intents. Functionality added in other places can be hard to find andor know about. Before i show you how to override a class, i want to ensure that you understand that monkeypatching is not considered a good practice. But nonetheless, the ability to monkey patch any class is extremely powerful.

Changing that class in some other file is a monkey patch. Extending rubys builtin classes is convenient but dangerous. In ruby, python, and many other dynamic programming languages, the term monkey patch only refers to dynamic modifications of a class or module at runtime, motivated by the intent to patch existing thirdparty code as a workaround to a bug or feature which does not act as desired. The monkeypatch ruby library one of the best, and worst, features of ruby is monkeypatching, extending the languages builtin classes and modules to suit your desires.