Why do they use js for the client side logic? Cant they use ruby? I know phonegap appelarator and rhomobile allow for this with rhomobile but all ruby. As im playing around with mobile applicaitons more im finding managing the javascript to be somewhat of a headache. So ive been wondering if theres ways to do with with other languages.

This is something I'd really like to see solved in client side frameworks like this.

It seems to me that you could do something similar to how ActiveRecord queries the database for a model's attributes - but instead expose a JSON service that returns a models attributes and validations. But perhaps JS doesn't have the dynamic / meta-programming capabilities to make this happen like Ruby does.