How to pass variables to render_to_string?

Question

Trying to do the following

@message = render_to_string ( :sender => sender, :template => \"template\" )          

But when accessing

Answer 1

Here's Jason Kim's solution he wrote in a comment which worked for me:

ActionController::Base.new.render_to_string(
  "user_mailer/welcome_email.html.erb", locals: { :@user => user}
)

Please mind the :@user => value bit.

---

In Rails 5 (atm in beta):

ApplicationController.render(
  file: 'path',
  assigns: { foo: 'bar' }
)

More here