FEATURE: add flair to avatars using new settings in the groups admin UI

lib/validators/url_validator.rb

@@ -0,0 +1,11 @@
+class UrlValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    if value.present?
+      uri = URI.parse(value) rescue nil
+
+      unless uri
+        record.errors[attribute] << (options[:message] || I18n.t('errors.messages.invalid'))
+      end
+    end
+  end
+end