add Recursively validation

@@ -334,3 +334,42 @@ func (v *Validation) Valid(obj interface{}) (b bool, err error) {
 
 	return !v.HasErrors(), nil
 }
+
+// Recursively validate a struct.
+// Step1: Validate by v.Valid
+// Step2: If pass on step1, then reflect obj's fields
+// Step3: Do the Recursively validation to all struct or struct pointer fields
+// Anonymous fields will be ignored
+func (v *Validation) RecursiveValid(objc interface{}) (bool, error) {
+	//Step 1: validate obj itself firstly
+	pass, err := v.Valid(objc)
+	if err != nil || false == pass {
+		return pass, err // Stop recursive validation
+	} else { //pass
+		// Step 2: Validate struct's struct fields
+		objT := reflect.TypeOf(objc)
+		objV := reflect.ValueOf(objc)
+		if isStruct(objT) || isStructPtr(objT) {
+
+			if isStructPtr(objT) {
+				objT = objT.Elem()
+				objV = objV.Elem()
+			}
+
+			for i := 0; i < objT.NumField(); i++ {
+
+				t := objT.Field(i).Type
+
+				if isStruct(t) || isStructPtr(t) {
+					// Step 3: do the recursive validation
+					// Only valid the Public field recursively
+					if objV.Field(i).CanInterface() {
+						pass, err = v.RecursiveValid(objV.Field(i).Interface())
+					}
+				}
+			}
+		}
+
+		return pass, err
+	}
+}

@@ -349,3 +349,33 @@ func TestValid(t *testing.T) {
 		t.Errorf("Message key should be `Name.Match` but got %s", valid.Errors[0].Key)
 	}
 }
+
+func TestRecursiveValid(t *testing.T) {
+	type User struct {
+		Id   int
+		Name string `valid:"Required;Match(/^(test)?\\w*@(/test/);com$/)"`
+		Age  int    `valid:"Required;Range(1, 140)"`
+	}
+
+	type AnonymouseUser struct {
+		Id2   int
+		Name2 string `valid:"Required;Match(/^(test)?\\w*@(/test/);com$/)"`
+		Age2  int    `valid:"Required;Range(1, 140)"`
+	}
+
+	type Account struct {
+		Password string `valid:"Required"`
+		U        User
+		AnonymouseUser
+	}
+	valid := Validation{}
+
+	u := Account{Password: "abc123_", U: User{}}
+	b, err := valid.RecursiveValid(u)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if b {
+		t.Error("validation should not be passed")
+	}
+}