struct can be null flag

validator_instance.go

@@ -150,20 +150,32 @@ func (v *Validate) SetTagName(name string) {
 	v.tagName = name
 }
 
+const omitemptyStructPrefix = "__omitempty_struct__"
+
 // ValidateMapCtx validates a map using a map of validation rules and allows passing of contextual
 // validation validation information via context.Context.
 func (v Validate) ValidateMapCtx(ctx context.Context, data map[string]interface{}, rules map[string]interface{}) map[string]interface{} {
 	errs := make(map[string]interface{})
 	for field, rule := range rules {
+		if strings.HasPrefix(field, omitemptyStructPrefix) == true {
+			continue
+		}
 		if ruleObj, ok := rule.(map[string]interface{}); ok {
-			if dataObj, ok := data[field].(map[string]interface{}); ok {
-				err := v.ValidateMapCtx(ctx, dataObj, ruleObj)
+			if dataObj, ok := data[field]; ok {
+				if do, ok := dataObj.(map[string]interface{}); ok {
+					err := v.ValidateMapCtx(ctx, do, ruleObj)
 					if len(err) > 0 {
 						errs[field] = err
 					}
 				} else {
 					errs[field] = errors.New("The field: '" + field + "' is not a map to dive")
 				}
+			} else if _, ok := rules[fmt.Sprintf("%s%s", omitemptyStructPrefix, field)].(string); ok {
+				// struct can be null
+				continue
+			} else {
+				errs[field] = errors.New("The field: '" + field + "' is not a map to dive")
+			}
 		} else if arrRuleObj, ok := rule.([]map[string]interface{}); ok {
 			if dataObjs, ok := data[field].([]map[string]interface{}); ok && len(arrRuleObj) > 0 {
 				for _, obj := range dataObjs {