validation_helpers.rb in sequel-3.7.0

- old
+ new
@@ -151,19 +151,24 @@
         # This validation does not respect the :allow_* options that the other validations accept,
         # since it can deal with a grouping of multiple attributes.
         #
         # Possible Options:
         # * :message - The message to use (default: 'is already taken')
+        # * :only_if_modified - Only check the uniqueness if the object is new or
+        #   one of the columns has been modified.
         def validates_unique(*atts)
           opts = default_validation_helpers_options(:unique)
           if atts.last.is_a?(Hash)
             opts = opts.merge(atts.pop)
           end
           message = validation_error_message(opts[:message])
           atts.each do |a|
-            ds = model.filter(Array(a).map{|x| [x, send(x)]})
+            arr = Array(a)
+            next if opts[:only_if_modified] && !new? && !arr.any?{|x| changed_columns.include?(x)}
+            ds = model.filter(arr.map{|x| [x, send(x)]})
             ds = yield(ds) if block_given?
-            errors.add(a, message) unless (new? ? ds : ds.exclude(pk_hash)).count == 0
+            ds = ds.exclude(pk_hash) unless new?
+            errors.add(a, message) unless ds.count == 0
           end
         end
         
         private
         