How to include CoffeeScript in Rails

Question

So CoffeeScript has shipped with Rails since 3.1? Fantastic! I'm getting into the syntax. I like simplicity.

And yet, I can't seem to figure out how to include it on my site. I've tried including it between and that didn't work.

I have one .erb file I want this to be in, new.html.erb (obviously, this is a Rails app):

<script type="text/coffeescript">
# Countdown to date script provided by JavaScriptKit.com
# http://www.javascriptkit.com/script/script2/count.shtml

montharray=new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec")

countdown(yr,m,d) ->
  today=new Date()
  todayy=today.getYear()

if (todayy < 1000)
  todayy+=1900
  todaym=today.getMonth()
  todayd=today.getDate()
  todaystring=montharray[todaym]+" "+todayd+", "+todayy
  futurestring=montharray[m-1]+" "+d+", "+yr

  difference=(Math.round((Date.parse(futurestring)-Date.parse(todaystring))/(24*60*60*1000))*1)

if (difference==0) and document.write(current)
  elseif (difference>0) document.write("ONLY "+difference+" DAYS LEFT!")

countdown(2012,4,30)

</script>​

And it doesn't show up at all. Ideas?

Solution

If you have CoffeeScript enabled, Rails will generate a .js.coffee file for each of your controllers in app/assets/javascripts. That's where your CoffeeScript belongs, and you don't need to include script tags.

Read more in the guide: http://guides.rubyonrails.org/asset_pipeline.html

Comments

[rumblestrut]

Alrighty, but how would I call this in my new.html.erb file? It's a countdown script.

[richardsun]

You would call the coffescript countdown function the same way you would call any javascript countdown function. Coffescript gets converted to javascript during compilation. You won't get very far if you haven't read and understood the Asset Pipeline guide.

[shashi verma]

but now it only produces .coffee not .js.coffee