- Composite pattern
- Multiple constraints on the same value by applying multiple validators
- Easy to create custom validators
- Easy to customize error messages
go get github.com/pengux/checkTo run tests:
cd $GOPATH/src/github.com/pengux/check && go testTo validate your data, create a new Struct and add validators to it:
type User struct {
Username string
}
func main() {
u := &User{
Username: "invalid*",
}
s := check.Struct{
"Username": check.Composite{
check.NonEmpty{},
check.Regex{`^[a-zA-Z0-9]+$`},
check.MinChar{10},
},
}
e := s.Validate(u)
if e.HasErrors() {
err, ok := e.GetErrorsByKey("Username")
if !ok {
panic("key 'Username' does not exists")
}
fmt.Println(err)
}
}To use your own custom validator, just implement the Validator interface:
type CustomStringContainValidator struct {
Constraint string
}
func (validator CustomStringContainValidator) Validate(v interface{}) check.Error {
if !strings.Contains(v.(string), validator.Constraint) {
return check.NewValidationError("customStringContainValidator", v, validator.Constraint)
}
return nil
}
func main() {
username := "invalid*"
validator := CustomStringContainValidator{"admin"}
e := validator.Validate(username)
fmt.Println(check.ErrorMessages[e.Error()])
}To use custom error messages, either overwrite the package variable ErrorMessages or create your own map[string]string:
check.ErrorMessages["minChar"] := "the string must be minimum %v characters long"
errMessages := errs.ToMessages()
fmt.Println(errMessages)For more example code check the file e2e_test.go.