custom validator cannot work when using ajax

Hi, I want to use custom validator to validate if the username is in database, however, when I use callback in validate functions, it cannot work, and always return false

<MyInput name='name' title='name' validations={{
    nameExistenceCheck: function (value) {
      if (value.name === undefined || value.name.length < 5) {
        return false;
      } else {
        // ajax
        DataSource.isNameExisted(value.name, function (response) {
          if (response.data.msg === 'available') {
            return true;
          }
        })
      }
    }
    }}  validationError='Length less than 5 or the name is already existed!'/>

[scotro]

The example would work for onSubmit, however onChange doesn’t provide an invalidate in the args it passes to the handler.

It is possible to set validation errors on the form component as an alternative to calling invalidate. Unfortunately, doing so appears to override the built-in validation at the component level.

[christianalfoni]

Let me know if is needed to discuss this more!