Using a Rails helper method within a javascript asset

Question

Is there any way to use a Rails helper method, more specifically, a path helper method within a javascript asset file. This file foo.js.coffee.erb

Answer 1

You can include any helper/module/class in an erb template with:

<% environment.context_class.instance_eval { include MyHelper } %>

See: https://github.com/rails/sprockets/blob/master/lib/sprockets/environment.rb and https://github.com/rails/sprockets/blob/master/lib/sprockets/context.rb

To use the url helpers you have to include your specific applications' helpers.

They are available at Rails.application.routes.url_helpers so:

<% environment.context_class.instance_eval { include Rails.application.routes.url_helpers } %>

EDIT: Fixed links to moved sprockets repo but not really sure this still makes sense so many years later.