I got the Javascript Inheritance code uploaded: Class.js
I’ve been keeping pretty busy getting our house ready to sell. About 2 weeks ago we found a house in U. City that we love…put an offer on it and it was accepted. Pending all inspections and such, we close March 30. So…we now have to move up our plans to sell our own house and do a few years of upgrades and painting in a week or so. So far Aislinn has been really busting her butt painting EVERYTHING and I’ve been remodeling the master bathroom and fixing random other things (and breaking others :)). I’ve gotten pretty comfortable with plumbing too. Then there is the presentation on OOJS on Monday. It’ll be fun, but so far, finding time to prepare has been almost impossible.
SO, about the code (if you haven’t been following the posts on it). The Class.js file provides an implementation of Classical Inheritance for Javascript. It does not involve newing up an instance of the superclass to set as the subclass’ prototype…I really didn’t like that approach. The implementation still builds a nice prototype chain though. It basically create’s an inline function…then sets that function’s prototype to the superclass prototype. Then it news up an instance of that inline ‘class’ and sets the subclasses prototype to that instance. So the prototype chain for instances of the subclass still actually contain a reference to the superclass’ prototype.
The code also adds a callSuper method to the subclass’ prototype. callSuper can be called from anywhere in the subclass and will result in a call to the superclass’ implementation of whatever method the call resides in (actually…it will find the first implementation further ‘up’ the ancestor chain…not neccessarily in the superclass). So, effectively, it knows how to find the overridden version of the calling method…and calls it. For Example:
function Shape(){
}
Shape.function.toString = function(){
return "Shape";
}
function Square(){
}
Class.extend(Square, Shape);
Square.prototype.toString = function(){
var str = this.callSuper();
return str + ': Square';
}
