I'm working on an ebook on GitHub on TDD JavaScript and I'm wondering if I'm missing any popular inheritance patterns. If you know of any additional patterns I'd love to see them. They should have the following: Time tested - used in real apps Source code should be supplied. Should be as straight forward and pedantic as possible. Of co...
I'm trying to force an inherited class to use a custom attribute. I'm creating a class library where the user who wants to create an item will do so, but be forced to add an attribute (or visual studio will automatically add the default attribute) to their inherited class. Here is what I'm hoping to achieve: BaseClass.vb: <CustomA...
I'm trying to do something similar to this post where I don't pull back all columns from a particular entity, however my framework makes use of inheritence and I lose scope of the entity type after it's been cast to an anonymous type. The structure of my Entity Framework has a base entity called Action. From here I've created two inhe...
Apple < ActiveRecord:Base Orange < ActiveRecord:Base piece_of_fruit = Apple.new I want to know whether piece_of_fruit is an Apple or an Orange - even though both are derived from ActiveRecord:Base. Is there a reflection method that will tell me the next class in the inheritance tree (Apple/Orange). What about if I want to look at ea...
I found this related question: http://stackoverflow.com/questions/279158/how-do-i-use-composition-with-inheritance I would like to do the same with Objective-C, that is to say that a GenericView knows that its property obj is a GenericObject, and that a SpecializedView knows that the very same obj property is a SpecializedObject. Here ...
I recently began trying my hand at using protocols in my Objective-C development as an (obvious) means of delegating tasks more appropriately among my classes. I completely understand the basic notion of protocols and how they work. However, I came across a roadblock when trying to create a custom protocol that in turn implements another...
Hello Is it possible to override a generisized function as illustrated in the code snippet below? interface A { } interface B extends A { } abstract class C { protected abstract <T extends A> void abc(T xyz); } class D extends C { @Override protected void abc(B xyz) { // doesn't compile // The method abc(B) of type ...
The title may be a bit ambiguous, but I couldn't think of a better way to word this. I realize that I can not call a derived constructor prior to calling a base constructor, but can I somehow modify / create parameters values prior to passing them to the base? For example, public enum InputType { Number = 1, String = 2, Da...
I'm a newbie to C#. I tried C++ and but found it too convoluted. Here's my question. If I use inheritance, and later realize that a subclass needs a method or field that is not applicable to the other parts, should I declare that in the base class and not have it implemented in the child classes, or should I declare that method or prope...
Hi all, I am looking to create an external library for Android that essentially provides an Activity that others can inherit from and the base Activity takes care of all the basic visual user interface stuff. So, it would be like the Mapping APIs that Google provides. Ideally it would be included in the manifest file in a manner similar ...
if (typeof Object.create !== 'function') { Object.create = function (o) { function F() {} F.prototype = o; return new F(); }; } var o1 = {}; o1.init = function(){ alert('o1'); }; var o2 = Object.create(o1); o2.init = function(){ // how would I call my ancessors init()? alert('o2'); }; o2.init(); ...
I have a rather generic model, as follows: class Keyword(models.Model): ancestors = models.ManyToManyField(Keyword) name = models.CharField() description = models.CharField() Trouble is, I have several different types of keywords, which all have different forms of business logic. Some, for example, are never allowed to hav...
suppose for example a program is to process complex numbers consisting of real and imaginary parts. in a complex number, the real and imaginary parts behave like real numbers so all of the operations (+,-,/,*,sqrt,sin,cos, etc) can be inherited form the class of objects called REAL instead of having to be written in code. Does the asse...
Hi all, I'm currently reading Dive Into Python by Mark Pilgrim, and have gotten to the section on inheritance. In section 5.5, Pilgrim mentions the differences between inheriting from the wrapper class UserDict vs inheriting from the built-in dict type. I'm having trouble understanding why anyone would even bother with the wrapper cla...
Can classes have multiple constructors and/or copy constructors in common-lisp? That is - in order to create a class for a new vector - "vecr" to represent 3-d vectors of real numbers, I'd like to define the new class that can be initialized in multiple ways: (vecr 1.2) ==> #(1.2 1.2 1.2) or (vecr 1.2 1.4 3.2) ==> #(1.2 4.3 2.5) or...
I was experimenting with variable constructor arguments for case classes in Scala, but am unable to pass them to the constructor of a case classes' parent: abstract case class Node(val blocks: (Node => Option[Node])*) case class Root(val elementBlocks: (Node => Option[Node])*) extends Node(elementBlocks) the above doesn't compile... i...
class Foo { } class Foo1 : Foo { } class Foo2 : Foo { } How would I be able to get all the classes that use Foo as a base class? The inherited classes aren't necessary in the same assembly. ...
In c# I am trying to implement a method which I can use to bind data to any control I pass to it (provided of course the control is derived from a databoundcontrol object) given the method public void CTLBindData(ref DataBoundControl ctl){ ... } I get an error when trying to pass derived control to the function for example the follo...
Hi, Consider this simple code: class A { }; class V1: vector<A *>{ // my nice functions }; if I have a instance of V1, then any object derived from A can be inserted into the vector, ok here. Now, lets say I have two simple classes called B and C both derives from A; if I have a instance of V1, then both pointers of B and C can...
I have an application.cfc in a subdir of my webroot: /app/application.cfc I recently added another application.cfc in a subdir of that and it extends the original application.cfc using the proxy method described here http://corfield.org/blog/index.cfm/do/blog.entry/entry/Extending_Your_Root_Applicationcfc : /app/mysubdir/application....