Ruby on Rails

Hello all, I followed the Heroku article on creating a Direct to S3 file uploader for my Rails app. https://devcenter.heroku.com/articles/direct-to-s3-image-uploads-in-rails I think that I did everything the tutorial said... In my users_controller, under new is: @s3_direct_post = S3_BUCKET.presigned_post(key: "uploads/#{SecureRandom.uuid}/${filename}", success_action_status: 201, acl: :public_read) This code seems fine, and is pretty much exactly as the article says. The problem is in my image_loader.js.erb, the following: fileInput.fileupload({ fileInput: fileInput, url: '<%= @s3_direct_post.url %>', type: 'POST', autoUpload: true, formData: <%= @s3_direct_post.fields.to_json.html_safe %>, Turns out: undefined method `url' for nil:NilClass in fact this breaks an otherwise working app. The code in my controller should create the @s3_direct_post object, but it seems that my javascript doesn't pick it up, maybe? I've tried putting the code in the view with <script> tags, as well, with the same results.  Any help out there? Thanks!