MooTools 1.2.2 is a mainly a bug fix release but it also includes an almost entirely new Class.js. The reasoning behind this is that the old Class.js didn’t play nicely with some advanced usages of this.parent() present in the new MooTools-More.
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Other than providing the parent fixes, the new Class also features a much more robust inheritance model, especially when dealing with objects. For example, the objects you implement now in a class are merged if an object with the same name is found in the class prototype…
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Another object-oriented feature we introduced is that now sub-objects are actually inherited Parent-to-Child. If you implement a new option in Animal, then Cat, which is a subclass of Animal, will get the new option as well, and so will every instance already existing.

Those are very cool features! Good job guys!
http://mootools.net/blog/2009/04/23/mootools-122-and-the-new-mootools-more/

Want more? Take a look at the new plugins available on Mootools More:
http://mootools.net/more

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