inheritance

Access static class variable of parent class in Python

I have someting like this class A: __a = 0 def __init__(self): A.__a = A.__a + 1 def a(self): return A.__a class B(A): def __init__(self): # how can I access / modify A.__a here? A.__a = A.__a + 1 # does not work def a(self): return A.__a Can I access the __a class variable in B? It's possible writing a ...

Multi-level inheritance with Implements on properties in VB.NET vs C#

Let's say I have 2 interfaces defined like so: public interface ISkuItem { public string SKU { get; set; } } public interface ICartItem : ISkuItem { public int Quantity { get; set; } public bool IsDiscountable { get; set; } } When I go to implement the interface in C#, VS produces the following templated code: public cl...

Is it possible to have function-specific variables viewable by extending components?

In Adobe Flex, it is possible to declare a public function, which can be overridden in a class that extends that function's class: public class class1 { public function method1 { public var var1:string = "hello world"; } } public class class2 extends class1 { override public function method1 { alert.show(sup...

Can reflection be used to instantiate an objects base class properties?

Like this: public class remoteStatusCounts : RemoteStatus { public int statusCount; public remoteStatusCounts(RemoteStatus r) { Type t = r.GetType(); foreach (PropertyInfo p in t.GetProperties()) { this.property(p) = p.GetValue(); //example pseudocode } } } The example ...

Calling Overriden Methods in Derived Class from Base Class

I was reading the Python docs about classes and came across this paragraph which I'm not sure about: Derived classes may override methods of their base classes. Because methods have no special privileges when calling other methods of the same object, a method of a base class that calls another method defined in the same b...

Castle ActiveRecord Class Table Inheritance

I'm trying to create Class Table Inheritance as in ( http://www.castleproject.org/activerecord/documentation/trunk/usersguide/typehierarchy.html ) So let's say I have 2 classes: [ActiveRecord("entity"), JoinedBase] public class Entity : ActiveRecordBase { private int id; private string name; private string type; ...and propert...

Python virtual classes: doing it right ?

I have been reading documentation describing class inheritance, abstract base classes and even python interfaces. But nothing seams to be exactly what I want. Namely, a simple way of building virtual classes. When the virtual class gets called, I would like it to instantiate some more specific class based on what the parameters it is giv...

Derived classes and singleton

Hello all, If I have two classes "A" and "B", is it OK to derive B from A and then make B a Singleton?. Thanks for your help. ...

SWIG support for inheritance of static member functions

SWIG doesn't wrap inherited static functions of derived classes. How it can be resolved? Here is a simple illustration of the problem. This is a simple C++ header file: // file test.hpp #include <iostream> class B { public: static void stat() { std::cerr << "=== calling static function B::stat" << std::endl; } void nonstat() c...

Object method gone after obj.prototype = new ParentObj(); in JavaScript

Hi, I am trying inherit objects in JavaScript. Take a look at this example: var BaseObject = function() { }; var ChildObject = function() { }; ChildObject.prototype.childMethod = function() { }; ChildObject.prototype = new BaseObject(); ChildObject.prototype.constructor = ChildObject(); However, as soon as I do prototypal inherita...

Storing a derived object inside another object as a base pointer (C++)

So here's the deal: I have a concrete class Window, representing an operating system window which will be be used for drawing. Window can take on many types, such as fullscreen, fixed window, resizable window, borderless window etc. This is implemented using an interface IWindowType, in which the specific types derive from (classes are ...

Call parent constructor before child constructor in PHP

Hey all, I was wondering if its possible to call the parents __construct(), before the child's __construct() with inheritance in PHP. Example: class Tag { __construct() { // Called first. } } class Form extends Tag { __construct() { // Called second. } } new Form(); Ideally, I would be able t...

JavaScript inheritance with Object.create()?

Hi, How do I inherit with the Object.create()? I tried these, but none are working: var B = function() {}; var A = function() {}; A = Object.create(B); A.prototype.C = function() {}; and var B = function() {}; var A = function() {}; A.prototype.C = function() {}; A = Object.create(B); and var B = function() {}; A = Object.create(...

Calling a function from a derived template class

My base class: //Element.h class Element { public: Element(); virtual ~Element(){}; // not sure if I need this virtual Element& plus(const Element&); virtual Element& minus(const Element&); }; Derived template class: //Vector.h #include "Element.h" template <class T> class Vector: public Element { T x, y, z; public: //constructors...

Have a child extend an already initialized parent in PHP

Hey all, I've been having a hard time coming up a solution with this one. I'm hoping you all can help me out. Best described with an example: class Parent { public $nationality; function __construct($nationality) { $this->nationality = $nationality } } class Child extends Parent { function __construct() {...

Virtual function calling using dereference object

I have a base class pointer pointing to derived class object. I am calling foo() function by using two different ways as mentioned below in Code. I want to know why in first case Derived:foo() is getting called. Shouldn't (*obj).foo() call Base:foo() function as it has already been dereferenced ? class Base { public: ...

Accessing a nonmember function of a derived class from a base class

I'm trying to call a nonmember function of a derived class from a base class, but getting this error: error: no matching function for call to 'generate_vectorlist(const char&)' Here's the relevant code snippets from the base class: //Element.cpp #include "Vector.h" ... string outfile; cin >> outfile; const char* outfile_name ...

problem with inheritance in python

in school we got this class file: class Konto: def __init__(self, nummer): self.__nr = nummer self.__stand = 0 self.__minimum = -1000.0 def getStand(self): return self.__stand def getNr(self): return self.__nr def einzahlen(self, betrag): self.__stand = self.__stand + be...

prevent meyer reset css to mess with dynamic content

Hi everyone, I implement the Eric Meyer's reset.css in my website, and works great, but it was a little problem, as this a CMS users are free to format the content of their articles as they want and the reset css resets the formating of their text. Any ideas how we can prevent reset.css inheritance to propagate to the dynamic content? ...

Check if object inherits from generic class

I have a generic list class: TMyObjectlist<T: TMyObject> = class(TObjectList<T>); and a derived list class: TMyDerivedObjectList = class(TMyObjectList<TMyDerivedObject>); I want to check if an instance MyList of TMyDerivedObjectList inherits from TMyObjectList, however: MyList.InheritsFrom(TMyObjectlist<TMyObject>) returns False...