Nowadays I've been toying around with the fabolous coffeescript language and I've created a basic model class.
This class allow you to use attr_accessor method as you can do in Ruby. If you don't know what attr_accessor is you can take a look here: Ruby attr_accessor.
Briefly what attr_accessor does is to let you access object attributes in "object.attribute" form (which in javascript is built in) but more importantly let you add a constrain on read/write permission of that attribute! In fact if you want the attribute to be readonly you need to use the "attr_reader" method, in the opposite case you need to use the "attr_writer" method. If you don't want to add any constraint you can use the "attr_accessor".

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