How to implement Active Record inheritance in Ruby on Rails?

Rails supports Single Table Inheritance. From the AR docs: Active Record allows inheritance by storing the name of the class in a column that by default is named “type” (can be changed by overwriting Base.inheritance_column). This means that an inheritance looking like this: class Company < ActiveRecord::Base; end class Firm < Company; end class Client … Read more

@Published property wrapper not working on subclass of ObservableObject

Finally figured out a solution/workaround to this issue. If you remove the property wrapper from the subclass, and call the baseclass objectWillChange.send() on the variable the state is updated properly. NOTE: Do not redeclare let objectWillChange = PassthroughSubject<Void, Never>() on the subclass as that will again cause the state not to update properly. I hope … Read more

C++ Access derived class member from base class pointer

No, you cannot access derived_int because derived_int is part of Derived, while basepointer is a pointer to Base. You can do it the other way round though: Derived* derivedpointer = new Derived; derivedpointer->base_int; // You can access this just fine Derived classes inherit the members of the base class, not the other way around. However, … Read more

Call base function then inherited function

C# doesn’t have support for automatically enforcing this, but you can enforce it by using the template method pattern. For example, imagine you had this code: abstract class Animal { public virtual void Speak() { Console.WriteLine(“I’m an animal.”); } } class Dog : Animal { public override void Speak() { base.Speak(); Console.WriteLine(“I’m a dog.”); } … Read more

Are private members inherited in C#?

A derived class has access to the public, protected, internal, and protected internal members of a base class. Even though a derived class inherits the private members of a base class, it cannot access those members. However, all those private members are still present in the derived class and can do the same work they … Read more

Inheritance best practice : *args, **kwargs or explicitly specifying parameters [closed]

Liskov Substitution Principle Generally you don’t want you method signature to vary in derived types. This can cause problems if you want to swap the use of derived types. This is often referred to as the Liskov Substitution Principle. Benefits of Explicit Signatures At the same time I don’t think it’s correct for all your … Read more

Super in Backbone

You’ll want to use:; This will call the original clone() method from Backbone.Model with the context of this(The current model). From Backbone docs: Brief aside on super: JavaScript does not provide a simple way to call super — the function of the same name defined higher on the prototype chain. If you override a … Read more