Add custom methods to Rails 3.1 asset pipeline?

Question

How can I add my custom methods to my assets such as css files like Rails did with 'asset_path' helper?

With Rail's own helper, I can write this:

# some.css.erb:

<%= asset_path 'a_image.png' %>

# How can I write this:

<%= my_custom_method 'a_image.png' %>

I've tried many ways but couldn't found a decent way to this. Do you know one?

Thanks

Answer 1

The best way I found was to create a custom helper module in app/helpers:

module AssetsHelper
  def my_custom_helper_method
    # do something  
  end
end

And then to require it like this in application.rb, after your applications configuration (very bottom):

module Sprockets::Helpers::RailsHelper
  require Rails.root.join('app', 'helpers', 'assets_helper.rb')
  include AssetsHelper
end

And you might follow this issue to find a better way: https://github.com/rails/rails/issues/3282

Answer 2

Normal helper methods are not available in asset views. To add you own methods you'll need to extend the Sprockets helper module. Have a look at the code of the built-in helpers to see how you might do this.

In a nutshell you can add a file in lib with the same structure as this and add you own methods. Don't forget to include the new library in you application initializer.