refactor render presence check into ModelFile method

Author: Floppy

app/components/preview_frame.rb

@@ -38,7 +38,7 @@ def render_local
       div class: "card-img-top #{"sensitive" if needs_hiding?}" do
         Renderer file: @file
       end
-    elsif @file.is_3d_model? && @file.attachment(:render)
+    elsif @file.has_render?
       image model_model_file_path(@file.model, @file, format: @file.extension, derivative: "render"), @file.name
     else
       empty

app/models/model_file.rb

@@ -83,6 +83,10 @@ def is_renderable?
     ["stl", "obj", "3mf", "ply", "gltf", "glb", "drc", "fbx", "3ds", "gcode", "mpd", "ldr", "3dm"].include? extension
   end
 
+  def has_render?
+    is_3d_model? && attachment_attacher.derivatives.key?(:render)
+  end
+
   def mime_type
     Mime::Type.lookup_by_extension(extension)
   end

app/views/model_files/show.html.erb

@@ -39,7 +39,7 @@
         </ul>
       <% end %>
       <%= Renderer(file: @file) %>
-    <% elsif @file.is_3d_model? && @file.attachment(:render) %>
+    <% elsif @file.has_render? %>
       <%= image_tag model_model_file_path(@model, @file, format: @file.extension, derivative: "render"), style: "width: 100%", alt: @file.name %>
     <% end %>
     <% if @file.notes %>

app/views/models/_file.html.erb

@@ -7,7 +7,7 @@
       <div class="card-img-top">
         <%= Renderer(file: file) %>
       </div>
-    <% elsif file.is_3d_model? && file.attachment(:render) %>
+    <% elsif file.has_render? %>
       <%= content_tag :div, nil, class: "card-img-top card-img-top-background", style: "background-image: url(#{model_model_file_path(@model, file, format: file.extension)})" %>
       <%= image_tag model_model_file_path(file.model, file, format: file.extension, derivative: "render"), class: "card-img-top image-preview", alt: file.name %>
     <% else %>