Jan Kassens, a MooTools contributor, has posted a nifty little trick to help you automatically bind methods to a class. Usually when we reference a method of a class when adding an event, we bind “this” to it to keep our reference to the class (this.addEvent(‘onComplete’, this.complete.bind(this))). This is great until we want to remove that event with removeEvent, which requires we reference the function again. the .bind method creates a copy of the function, so we have to store a reference to it. It’s all very messy. Introducing the Binds mutator. Look for it in the next MooTools patch release, but you can start using it now if you just include the 10 lines Jan has posted.

I wasn’t quite happy with this solution, because it’s too verbose: why always use this.bound.myFn when I always want the bound one? Secondly, I don’t want to do the binding of all these functions by hand. After some discussions on different solutions this is what I come up with as the optimum between speed (don’t worry its faster than the solution above) and usability.

A new so called “class mutator” named Binds. Most of you probably didn’t hear of class mutators before, but you sure have used a class mutator before when you’ve written one or another class. Built in mutators are Implements and Extends...