Adding error messages to domain object in Grails

Sometimes it is more convenient to do some validation outside of the domain object, on the other side it is still nice to use standard error reporting facilities. For these cases, you can inject errors into domain objects like:

    if (someError) {
      domainobject.errors.rejectValue('param', "hasErrors")
    }
    ...
    if (!domainobject.hasErrors() && domainobject.save(flush: true)) {
    ...