get the username value of user in FOSuserBundle - symfony

Question

I have a many to many entity relationship, User and Project
The User entity has only one field, the id field since it is extending the FOsUserBundle. I understand that to access the current logged in users by calling the container
$user = $this->container->get('security.context')->getToken()->getUser();
But that's not the case.A project has many users saved in a database.Now I can access it by using a twig loop
users_projects//a many to many table
project_id user_id
3 1
3 2
<td>{% for user in project.users %}{{ user.id}}{% endfor %}</td>
outputs 1,2
The user entity has no getUsername method as it has only one id field.How would you display the username instead of an i.d?
Update
Already solved this.I dont really sure if its the proper way .In ProjectType, I added this
->add('users', 'entity', array(
'class' => 'UserBundle:User',
'query_builder' => function (EntityRepository $er) {
return $er->createQueryBuilder('u')
->orderBy('u.username', 'ASC');
},
'expanded' => true,
'multiple' => true
))
With this set up
<td>
{% for user in entity.users %}
{{ user.username }}
{% if not loop.last %},{% endif %}
{% endfor %}
</td>
Now works.Just don't forget to include
use Doctrine\ORM\EntityRepository;
In FormType, else it will throw an error something like
Catchable Fatal Error: Argument 1 passed to.....must be an instance of \EmployeeBundle\Form\EntityRepository, instance of Doctrine\ORM\EntityRepository given