Rails Javascript compression/minification on respond_to javascript response?

Greetings Rails and Javascript Gu开发者_JS百科rus!

I have a project where I am returning a large javascript file in a

respond_to do |format|
   format.js
end

block.

I am trying to figure out how I can minify or compress the .js response since the .js.erb view is full of comments and varies in size based on the results from the controller.

Anyone have any ideas?

---

For Rails 4:

render js: Uglifier.new.compile(render_to_string)

---

well, maybe I have a solution:

respond_to do |format|
  format.js { self.response_body = minify(render_to_string) }
end

This perfectly works. Of course that the key is the minify method. You will find a lot of JS minifiers around. For example you can use this one (well if license permits): http://github.com/thumblemonks/smurf/raw/master/lib/smurf/javascript.rb - it is based on Crockford's jsmin.c.

If you put this file into your lib, require it, your minify method can look like this:

def minify(content)
  min = Smurf::Javascript.new(content)
  min.minified
end

Hope that it helped you.

If you plan to do minifying automatically then you probably should go for a piece of middleware. Surprisingly I was not able to find any (there are many aimed to the CSS/JS but it's about static assets not dynamic content) but it would not be such a problem to write it.

---

For rails 3 using the built in Uglifier method (the default for the assets pipeline)

See Radek's code above and just swap this in.

  def minify(content)
    Uglifier.new.compile(content)
  end