Allowing User to Download File from S3 Storage

Question

Right now I am using Amazon S3 and Paperclip which is allowing my users to upload an image that is associated with the event they are creating. My ultimate goal is since others can view this event, to be able to click on the image and have it prompt a SAVE TO their computer. As of now, clicking the link will open the image in a browser window. I rather have it ask for them to download instead. All images only saved on S3, not local. Need to hide exposed s3 url as well if possible or camouflage it

Here is my current setup

Index.html

<%= link_to 'Download Creative', event.creative.url, class: "btn btn-info" %>

Event.rb

has_attached_file :creative,
                :styles => { :thumb => "150x150", :custcreative => "250x75" },
                :path => ":attachment/:id/:style.:extension",
                :s3_domain_url => "******.s3.amazonaws.com",
                :storage => :s3,
                :s3_credentials => Rails.root.join("config/s3.yml"),
                :bucket => '*****',
                :s3_permissions => :public_read,
                :s3_protocol => "http",
                :convert_options => { :all => "-auto-orient" },
                :encode => 'utf8'

Hoping someone can help me out.

Answer 1

To avoid extra load to your app (saving dyno's time in Heroku), I would rather do something like this: add this method to your model with the attachment:

def download_url(style_name=:original)
  creative.s3_bucket.objects[creative.s3_object(style_name).key].url_for(:read,
      :secure => true,
      :expires => 24*3600,  # 24 hours
      :response_content_disposition => "attachment; filename='#{creative_file_name}'").to_s
end

And then use it in your views/controllers like this:

<%= link_to 'Download Creative', event.download_url, class: "btn btn-info" %>

Answer 2

To make this work, I've just added a new action in the controller, so in your case it could be:

#routes
resources :events do
  member { get :download }
end

#index
<%= link_to 'Download Creative', download_event_path(event), class: "btn btn-info" %>

#events_controller
def download
  data = open(event.creative_url)
  send_data data.read, :type => data.content_type, :x_sendfile => true
end

EDIT: the correct solution for download controller action can be found here (I've updated the code above): Force a link to download an MP3 rather than play it?