add RequestStore gem, support universal only param for api endpoints (fixes #4068)

app/models/application_record.rb

@@ -149,12 +149,25 @@ class ApplicationRecord < ActiveRecord::Base
 
     def as_json(options = {})
       options ||= {}
+
       options[:except] ||= []
       options[:except] += hidden_attributes
 
       options[:methods] ||= []
       options[:methods] += method_attributes
 
+      if !options.key?(:only) && RequestStore.exist?(:only_param)
+        options[:only] = RequestStore[:only_param]
+      end
+
+      if options[:only].is_a?(String)
+        options[:only] = options[:only].split(/,/)
+      end
+
+      if options[:only]
+        options[:methods] = options[:methods] & options[:only]
+      end
+
       super(options)
     end
 
@@ -167,6 +180,18 @@ class ApplicationRecord < ActiveRecord::Base
       options[:methods] ||= []
       options[:methods] += method_attributes
 
+      if !options.key?(:only) && RequestStore.exist?(:only_param)
+        options[:only] = RequestStore[:only_param]
+      end
+
+      if options[:only].is_a?(String)
+        options[:only] = options[:only].split(/,/)
+      end
+
+      if options[:only]
+        options[:methods] = options[:methods] & options[:only]
+      end
+
       super(options, &block)
     end