http://jdj.sys-con.com/read/152288.htm
On 12/28/05, Ryan Gahl <[EMAIL PROTECTED]> wrote:
Dear Original Poster,
Try this...
superClass = Class.create();
superClass.prototype = { blah blah blah... }
subclass = Class.create();
subclass.prototype = {
initialize: function(name, position) {
Object.extend(this, new superClass(name));
this.position = position;
}
}
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto: [EMAIL PROTECTED]] On Behalf Of Cliff
Mees
Sent: Monday, December 26, 2005 9:20 PM
To: rails-spinoffs@lists.rubyonrails.org
Subject: Re: [Rails-spinoffs] Re: Prototype OOP example
Victor,
Thanks for putting that clearer (and more correctly) than I did!
Object#extend does return the extended object, but also affects the
first parameter ("destination") in-place, extending it without
requiring the return.
My initial example actually re-defined the base class in terms of the
inherited class (i.e. Labour and Worker had the same definitions --
oops!).
I take it that the return from Object#extend is provided to allow
things like:
Object.extend(base_obj, {newMethod: function() { // do
something }}).newMethod();
Cheers,
Cliff
On Dec 26, 2005, at 15:56, Victor Borja wrote:
> QnA wrote:
>> Thank you for your example. It is a bit disappointed to me that it
>> is not
>> possible to call the superclass's constructor in prototype.
>
> There's no such thing as a REAL class in _javascript_ (in the sense of
> classes as in java, ruby, etc), you have objects (wich have
> properties)
> and functions (wich are objects).
>
> In JS you get only _Initializer Functions_, and fake class
> inheritance by
> calling another initializer within your _subclass_.
> Checkout http://_javascript_-reference.info/#oop
>
> /* Labour is just a _Constructor Function_.
> Prototype's Class.create just returns a new function that calls
> this.initialize to follow the ruby OO tradition */
> Labour = Class.create ();
> Labour.prototype = {
> initialize: function(name) {
> this.name = name;
> },
>
> showYourName: function() {
> alert( this.name);
> }
> }
>
> /* Worker will be a subclass of Labour */
> Worker = Class.create();
> /* Thanks to Prototype's Object.extend you can copy all properties
> from
> an object to another, we are using this to get all the Labour
> functions in Worker, just as if we had inheritance */
> Object.extend(Worker.prototype, Labour.prototype);
> /* Next extend our _subclass_, note that we are not using something
> like:
> Worker.prototype = { // bla bla }
> Because we would be throwing away all the Labour.prototype
> properties,
> Instead we just use Object.extend again.
> */
> Object.extend(Worker.prototype, {
>
> /* define our _subclass_ initializer, this overrides the old
> Labour#initialize.
> We could as well, backup the old initializer. I named it
> _super_
> but it could be whatever you like.
> */
> super: Labour.prototype.initialize,
>
> initialize: function(name, position) {
> // Calling the _superclass_ initializer
> super.call(this, name);
> this.position = position;
> },
>
> showYourPosition: function() {
> alert(this.position);
> },
>
> });
>
> Regards,
> --
> vic
>
> _______________________________________________
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> Rails-spinoffs@lists.rubyonrails.org
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