render_to_string in sidekiq worker

Question

I'm trying to do some PDF generation in my app which processes some data and then creates the PDF of the result. I'm using PDFKit so need to simply create an HTML view which is fine if I'm in a controller, but I want to push the processing into a background thread with Sidekiq.

I had planned to use render_to_string but due to it being part of a Controller only, I can't use it in Sidekiq.

Is there some way I can do this? I'd like to try and stick with Sidekiq but if not then I guess I just have to do it all within the controller?

Answer 1

OK I've gone for a different approach.

I've created an abstract controller that is being called directly from the worker class, as describe here http://www.whatastruggle.com/generating-pdfs-in-background

Thanks anyway

Edit

Seems the link is dead, so to sum up what worked:

Create a new controller, this will be the rendering controller

rendering_controller.rb

class RenderingController < AbstractController::Base
  include AbstractController::Rendering
  include ActionView::Layouts
  include AbstractController::Helpers
  include AbstractController::Translation
  include AbstractController::AssetPaths
  include Rails.application.routes.url_helpers
  include WickedPdf::PdfHelper

  self.view_paths = 'app/views'
end

Then wherever you need to use it

rc = RenderingController.new
rc.render_to_string(template: 'template/name', locals: { local: value })

Note this is no longer required if you're using Rails 5+ since they enabled rendering outside of controllers. Instead you can now just do:

ApplicationController.render :index

More details are available here

Answer 2

Why couldn't you render_to_string in the controller, store the returned HTML in a variable, pass the HTML into a sidekiq job?