make new model for stringSlices allowOrigin helper

models/stringSlices.go

@@ -0,0 +1,14 @@
+package models
+
+import "strings"
+
+type StringSlice []string
+
+func (s *StringSlice) String() string {
+	return strings.Join(*s, ",")
+}
+
+func (s *StringSlice) Set(value string) error {
+	*s = append(*s, value)
+	return nil
+}