You could use CGLIB for that. The class Mixin is able to generate a dynamic class from several interfaces / object delegates: static Mixin create(java.lang.Class[] interfaces, java.lang.Object[] delegates) static Mixin create(java.lang.Object[] delegates) static Mixin createBean(java.lang.Object[] beans)
Compatible with Rails 3,4 and 5: view_context.link_to
It is easy, when declaring a class you just use the “with” keyword as often as you want class CollegeStudent extends Student with Worker with Underpaid with Young the order of the traits can be important if a trait is changing the behavior of the class, it all depends on traits you are using. Also … Read more
Sorry I saw this so late, but class MixedClass2(SomeMixin, MyClass): pass >>> m = MixedClass2() mixin before base mixin after The pattern @Ignacio is talking about is called cooperative multiple inheritance, and it’s great. But if a base class isn’t interested in cooperating, make it the second base, and your mixin the first. The mixin’s … Read more
It really depends on what you mean by “mixin” – everyone seems to have a slightly different idea. The kind of mixin I’d like to see (but which isn’t available in C#) is making implementation-through-composition simple: public class Mixin : ISomeInterface { private SomeImplementation impl implements ISomeInterface; public void OneMethod() { // Specialise just this … Read more
A lot of the problems that people have with mix-ins can be averted in Scala if you only mix-in abstract traits into your class definitions, and then mix in the corresponding concrete traits at object instantiation time. For instance trait Locking{ // abstract locking trait, many possible definitions protected def lock(body: =>A):A } class MyService{ … Read more
Mixins is all about how a class does what it does, it’s inheriting and sharing concrete implementation. Interfaces is all about what a class is, it is the abstract signature and promises that the class must satisfy. It’s a type. Take a class that is implemented as class MyList<T> extends Something with ListMixin<T> …. You … Read more
Before going into what a mix-in is, it’s useful to describe the problems it’s trying to solve. Say you have a bunch of ideas or concepts you are trying to model. They may be related in some way but they are orthogonal for the most part — meaning they can stand by themselves independently of … Read more
Abstract Class An abstract class is a class that is not designed to be instantiated. Abstract classes can have no implementation, some implementation, or all implementation. Abstract classes are designed to allow its subclasses share a common (default) implementation. A (pseudocoded) example of an abstract class would be something like this abstract class Shape { … Read more
A common idiom is to use included hook and inject class methods from there. module Foo def self.included base base.send :include, InstanceMethods base.extend ClassMethods end module InstanceMethods def bar1 ‘bar1’ end end module ClassMethods def bar2 ‘bar2’ end end end class Test include Foo end Test.new.bar1 # => “bar1” Test.bar2 # => “bar2”