Render templates outside the controller in a Rails app

README.md

You templates must live in app/views, as usual. To render it, just use something like below.

Renderer.render(template: "message", locals: {name: "John Doe"});

message.html.erb

<!-- app/views/message.html.erb -->
Hi there, <%= name %>.

renderer.rb

module Renderer
  def self.render(options = {})
    view = View.new(ActionController::Base.view_paths)
    view.extend(ApplicationHelper)
    view.render(options)
  end

  class View < ActionView::Base
    include Rails.application.routes.url_helpers
  end
end