use signed uuid in previews

app/controllers/api/templates_documents_controller.rb

@@ -16,7 +16,7 @@ def create
       render json: {
         schema:,
         documents: documents.as_json(
-          methods: [:metadata],
+          methods: %i[metadata signed_uuid],
           include: {
             preview_images: { methods: %i[url metadata filename] }
           }

app/controllers/preview_document_page_controller.rb

@@ -6,7 +6,16 @@ class PreviewDocumentPageController < ActionController::API
   FORMAT = Templates::ProcessDocument::FORMAT
 
   def show
-    attachment = ActiveStorage::Attachment.find_by(uuid: params[:attachment_uuid])
+    attachment_uuid = ApplicationRecord.signed_id_verifier.verified(params[:signed_uuid])
+
+    attachment =
+      if attachment_uuid
+        ActiveStorage::Attachment.find_by(uuid: attachment_uuid)
+      else
+        Rollbar.warning("Load preview from uuid: #{params[:signed_uuid].to_s.first(10)}") if defined?(Rollbar)
+
+        ActiveStorage::Attachment.find_by(uuid: params[:signed_uuid])
+      end
 
     return head :not_found unless attachment
 
@@ -21,9 +30,10 @@ def show
         find_or_create_document_tempfile_path(attachment)
       end
 
-    io = Templates::ProcessDocument.generate_pdf_preview_from_file(attachment, file_path, params[:id].to_i)
+    preview_image =
+      Templates::ProcessDocument.generate_pdf_preview_from_file(attachment, file_path, params[:id].to_i)
 
-    render plain: io.tap(&:rewind).read, content_type: 'image/jpeg'
+    redirect_to preview_image.url, allow_other_host: true
   end
 
   def find_or_create_document_tempfile_path(attachment)

app/controllers/templates_controller.rb

@@ -33,7 +33,7 @@ def edit
     @template_data =
       @template.as_json.merge(
         documents: @template.schema_documents.as_json(
-          methods: [:metadata],
+          methods: %i[metadata signed_uuid],
           include: { preview_images: { methods: %i[url metadata filename] } }
         )
       ).to_json

app/controllers/templates_preview_controller.rb

@@ -12,7 +12,7 @@ def show
     @template_data =
       @template.as_json.merge(
         documents: @template.schema_documents.as_json(
-          methods: [:metadata],
+          methods: %i[metadata signed_uuid],
           include: { preview_images: { methods: %i[url metadata filename] } }
         )
       ).to_json

app/javascript/template_builder/document.vue

@@ -102,7 +102,7 @@ export default {
         return this.previewImagesIndex[i] || {
           metadata: lazyloadMetadata,
           id: Math.random().toString(),
-          url: this.basePreviewUrl + `/preview/${this.document.uuid}/${i}.jpg`
+          url: this.basePreviewUrl + `/preview/${this.document.signed_uuid || this.document.uuid}/${i}.jpg`
         }
       })
     },

app/views/submissions/show.html.erb

@@ -53,7 +53,7 @@
           <% preview_images_index = document.preview_images.loaded? ? document.preview_images.index_by { |e| e.filename.base.to_i } : {} %>
           <% lazyload_metadata = document.preview_images.first.metadata %>
           <% (document.metadata.dig('pdf', 'number_of_pages') || (document.preview_images.loaded? ? preview_images_index.size : document.preview_images.size)).times do |index| %>
-            <% page = preview_images_index[index] || page_blob_struct.new(metadata: lazyload_metadata, url: preview_document_page_path(document.uuid, "#{index}.jpg")) %>
+            <% page = preview_images_index[index] || page_blob_struct.new(metadata: lazyload_metadata, url: preview_document_page_path(document.signed_uuid, "#{index}.jpg")) %>
             <div id="<%= "page-#{document.uuid}-#{index}" %>" class="relative">
               <img loading="lazy" src="<%= page.url %>" width="<%= page.metadata['width'] %>" class="border rounded mb-4" height="<%= page.metadata['height'] %>">
               <div class="top-0 bottom-0 left-0 right-0 absolute">

app/views/submit_form/show.html.erb

@@ -13,7 +13,7 @@
         <% preview_images_index = document.preview_images.loaded? ? document.preview_images.index_by { |e| e.filename.base.to_i } : {} %>
         <% lazyload_metadata = document.preview_images.last.metadata %>
         <% (document.metadata.dig('pdf', 'number_of_pages') || (document.preview_images.loaded? ? preview_images_index.size : document.preview_images.size)).times do |index| %>
-          <% page = preview_images_index[index] || page_blob_struct.new(metadata: lazyload_metadata, url: preview_document_page_path(document.uuid, "#{index}.jpg")) %>
+          <% page = preview_images_index[index] || page_blob_struct.new(metadata: lazyload_metadata, url: preview_document_page_path(document.signed_uuid, "#{index}.jpg")) %>
           <div class="relative my-4 shadow-md">
             <img loading="lazy" src="<%= page.url %>" width="<%= page.metadata['width'] %>" height="<%= page.metadata['height'] %>">
             <div id="page-<%= [document.uuid, index].join('-') %>" class="top-0 bottom-0 left-0 right-0 absolute">

config/initializers/active_storage.rb

@@ -5,6 +5,10 @@
 
   has_many_attached :preview_images
 
+  def signed_uuid
+    @signed_uuid ||= ApplicationRecord.signed_id_verifier.generate(uuid, expires_in: 6.hours)
+  end
+
   def preview_image_url
     preview_images.joins(:blob).find_by(blob: { filename: '0.jpg' })&.url
   end

config/routes.rb

@@ -81,7 +81,7 @@
     resource :code_modal, only: %i[show], controller: 'templates_code_modal'
     resources :submissions_export, only: %i[index new]
   end
-  resources :preview_document_page, only: %i[show], path: '/preview/:attachment_uuid'
+  resources :preview_document_page, only: %i[show], path: '/preview/:signed_uuid'
 
   resources :start_form, only: %i[show update], path: 'd', param: 'slug' do
     get :completed

lib/templates/process_document.rb

@@ -98,8 +98,6 @@ def generate_pdf_preview_from_file(attachment, file_path, page_number)
           record: attachment
         )
       end
-
-      io
     end
   end
 end