[General] Fwd: Why using Object.extend?

[Robert Krahn]

Hi, Haowei.

Those properties and functions defined in the subclass construct are  
defined for instances of the class, i.e. they are added to the  
prototype property of a class. Object.extend, however, adds functions  
and properties directly to the given object, not its prototype property.

Robert


On Apr 25, 2009, at 2:16 PM, Haowei Ruan wrote:

> Hi, i do not understand why still uses Object.extend, can't those
> properties be defined within the "subclass" construct?
> Thanks in advance!
>
> regards,
> Haowei
>
> code snippet:
> --------------------------------------------------------
> Gradient.subclass("LinearGradient", {
>
>   initialize: function($super, stopColor1, stopColor2, vector) {
>       vector = vector || LinearGradient.NorthSouth;
>       this.rawNode = NodeFactory.create("linearGradient",
>                      {x1: vector.x, y1: vector.y,
>                       x2: vector.maxX(), y2: vector.maxY()});
>       this.addStop(0, stopColor1).addStop(1, stopColor2);
>       return this;
>   }
>
> });
>
> Object.extend(LinearGradient, {
>   NorthSouth: rect(pt(0, 0), pt(0, 1)),
>   SouthNorth: rect(pt(0, 1), pt(0, 0)),
>   EastWest:   rect(pt(0, 0), pt(1, 0)),
>   WestEast:   rect(pt(1, 0), pt(0, 0))
> });
> ---------------------------------------------------------
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