Show a thumbnail of all representable Active Storage files

not only images

Author: wvengen

lib/rails_admin/config/fields/types/active_storage.rb

@@ -18,10 +18,7 @@ class ActiveStorage < RailsAdmin::Config::Fields::Types::FileUpload
           end
 
           register_instance_option :image? do
-            if value
-              mime_type = Mime::Type.lookup_by_extension(value.filename.extension_without_delimiter)
-              mime_type.to_s.match?(/^image/)
-            end
+            value.representable? if value
           end
 
           register_instance_option :eager_load do
@@ -43,11 +40,11 @@ class ActiveStorage < RailsAdmin::Config::Fields::Types::FileUpload
           def resource_url(thumb = false)
             return nil unless value
 
-            if thumb && value.variable?
+            if thumb && value.representable?
               thumb = thumb_method if thumb == true
-              variant = value.variant(thumb)
+              repr = value.representation(thumb)
               Rails.application.routes.url_helpers.rails_blob_representation_path(
-                variant.blob.signed_id, variant.variation.key, variant.blob.filename, only_path: true
+                repr.blob.signed_id, repr.variation.key, repr.blob.filename, only_path: true
               )
             else
               Rails.application.routes.url_helpers.rails_blob_path(value, only_path: true)

lib/rails_admin/config/fields/types/multiple_active_storage.rb

@@ -23,19 +23,16 @@ class ActiveStorageAttachment < RailsAdmin::Config::Fields::Types::MultipleFileU
             end
 
             register_instance_option :image? do
-              if value
-                mime_type = Mime::Type.lookup_by_extension(value.filename.extension_without_delimiter)
-                mime_type.to_s.match?(/^image/)
-              end
+              value.representable? if value
             end
 
             def resource_url(thumb = false)
               return nil unless value
 
-              if thumb && value.variable?
-                variant = value.variant(thumb_method)
+              if thumb && value.representable?
+                repr = value.representation(thumb_method)
                 Rails.application.routes.url_helpers.rails_blob_representation_path(
-                  variant.blob.signed_id, variant.variation.key, variant.blob.filename, only_path: true
+                  repr.blob.signed_id, repr.variation.key, repr.blob.filename, only_path: true
                 )
               else
                 Rails.application.routes.url_helpers.rails_blob_path(value, only_path: true)