subclassing

When you are subclassing objects and want to extend the initialization code, there are two approaches. Overriding __construct(), and implementing an initialization method that your superclass constructor calls. Method 1: class foo { public function __construct ($arg1, $arg2, $arg3) { // Do initialization } } class bar extends foo { public function __construct ($arg1, $arg2, $arg3) { parent::__construct ($arg1, $arg2, $arg3); // Do subclass initialization } } Method 2 class foo { public function init () { // Dummy function } public function __construct ($arg1, $arg2, $arg3) { // Do subclass

Since I updated jQueryUI to 1.8 I found a couple of issues in our implementations and I could fix it myself without waiting for a fix on their end if I could find out how to subclass a specific method of the datepicker widget so I call the parent code and then execute my code. I was reading on $.widget but I just can't wrap my head around how that is suppose to work. I tried something like this: $.widget("ui.datepicker", { _showDatepicker: function(input) { alert('Yo'); $.datepicker.prototype._showDatepicker.apply(this,arguments); alert('Hey!'); } }); And all sorts of other variations and

I have a custom figure class and would like to ensure that all of the axes associated with it, whether created with subplots() or twinx() , etc. have custom behaviors. Right now I accomplish this by binding new methods to each axis after it has been created, e.g. by using import types def my_ax_method(ax, test): print('{0} is doing something new as a {1}.'.format(ax, test)) class MyFigure(matplotlib.figure.Figure): def __init__(self, **kwargs): super(MyFigure, self).__init__(**kwargs) axes_a = None axes_b = None axes_c = None def setup_axes(self, ax): self.axes_a = ax self.axes_b = self.axes_a

I'm creating a game in which I have a somewhat complex method for creating entities. When a level is loaded, the loading code reads a bunch of YAML files that contain attributes of all the different possible units. Using the YAML file, it creates a so-called EntityResource object. This EntityResource object serves as the authoritative source of information when spawning new units. The goal is twofold: Deter cheating by implementing a hash check on the output of the YAML file Aid in debugging by having all unit information come from a single, authoritative source. These EntityResource objects

I wanted to subclass UINavigationBar (to set a custom background image & text color) and use that for all the navigation bars in my app. Looking at the API docs for UINavigationController, it looks like navigationBar is read-only: @property(nonatomic, readonly) UINavigationBar *navigationBar Is there a way to actually use a custom UINavigationBar in my UIViewControllers? I know that other apps have done custom navigation bars, like flickr: http://img.skitch.com/20100520-bpxjaca11h5xne5yakjdc2m6xx.png Here is my UINavigationBar subclass: #import <UIKit/UIKit.h> @interface MyNavigationBar :

Suppose I have the class class A { protected: int x,y; double z,w; public: void foo(); void bar(); void baz(); }; defined and used in my code and the code of others. Now, I want to write some library which could very well operate on A's, but it's actually more general, and would be able to operate on: class B { protected: int y; double z; public: void bar(); }; and I do want my library to be general, so I define a B class and that's what its APIs take. I would like to be able to tell the compiler - not in the definition of A which I no longer control, but elsewhere, probably in the definition