XML : Symfony2 custom validation not working

I have a problem with custom validation. I want it to look like this: valid or something like this...

But it doesnt working at all. My controller: http://pastebin.com/aeDQRVyD

validation.xml under AppBundle\Resources\config

  <constraint-mapping>  <class name="AppBundle\Entity\Oferty">        <property name="tytul">          <constraint name="NotBlank">              <option name="message">Tytul jest pusty</option>          </constraint>          <constraint name="Length">              <option name="min">3</option>              <option name="minMessage">Tytul jest za krótki</option>              <option name="max">15</option>              <option name="maxMessage">Tytul jest za długi</option>          </constraint>      </property>  </class>    

Its not even validating.. How i can work this out?