Merge pull request #3255 from kallelundgren93/active_storage_variants/image_processing_vs_mm

Active storage variants in Rails 6>

Author: mshibuya

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

@@ -8,7 +8,11 @@ class ActiveStorage < RailsAdmin::Config::Fields::Types::FileUpload
           RailsAdmin::Config::Fields::Types.register(self)
 
           register_instance_option :thumb_method do
-            {resize: '100x100>'}
+            if Gem.loaded_specs.key?('ruby-vips')
+              {resize_to_limit: [100, 100]}
+            else
+              {resize: '100x100>'}
+            end
           end
 
           register_instance_option :delete_method do

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

@@ -9,7 +9,11 @@ class MultipleActiveStorage < RailsAdmin::Config::Fields::Types::MultipleFileUpl
 
           class ActiveStorageAttachment < RailsAdmin::Config::Fields::Types::MultipleFileUpload::AbstractAttachment
             register_instance_option :thumb_method do
-              {resize: '100x100>'}
+              if Gem.loaded_specs.key?('ruby-vips')
+                {resize_to_limit: [100, 100]}
+              else
+                {resize: '100x100>'}
+              end
             end
 
             register_instance_option :delete_value do