Rails dynamic select menu for 3.1

How would this be updated for Rails 3.1?

http://rai开发者_运维问答lscasts.com/episodes/88-dynamic-select-menus

I just can't figure out how to call the js.erb file and have it run the code to generate the javascript dynamically.

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Might be something: in Rails 3.1, you're most likely using jQuery instead of Prototype. The example code on the Railscasts site is using good old Prototype instead of the new hotness that is jQuery (default javascript library in Rails 3.1).

Once all your jquery pipes are connected, having rails respond to and render your js.erb is the same as always. In your controller:

def country_selected

    // whatever you need to do 

    respond_to do |format|
        format.js
    end
end

Then in your view directory, you have a country_selected.js.erb that you can put in whatever javascript you want to update the second select menu. (Remember you have to escape your shiz for it to work correctly) e.g.

<%= escape_javascript(params[:country]) %>

By the way, I think .rjs was moved out of Rails proper and into it's own Gem. Something else to keep in mind regarding Rails 3.1 vs. javascript.