1 files changed, 20 insertions, 0 deletions
diff --git a/app/validators/color_validator.rb b/app/validators/color_validator.rb
new file mode 100644
index 00000000000..571d0007aa2
--- /dev/null
+++ b/app/validators/color_validator.rb
@@ -0,0 +1,20 @@
+# ColorValidator
+#
+# Custom validator for web color codes. It requires the leading hash symbol and
+# will accept RGB triplet or hexadecimal formats.
+#
+# Example:
+#
+#   class User < ActiveRecord::Base
+#     validates :background_color, allow_blank: true, color: true
+#   end
+#
+class ColorValidator < ActiveModel::EachValidator
+  PATTERN = /\A\#[0-9A-Fa-f]{3}{1,2}+\Z/.freeze
+
+  def validate_each(record, attribute, value)
+    unless value =~ PATTERN
+      record.errors.add(attribute, "must be a valid color code")
+    end
+  end
+end