Symfon2: How to set default values (options) for Entity field type? - forms

Question

I am creating a form which uses an Entity type.
The entity form type displays Roles as a list of checkboxes.
But I dont know how to set default values. I need to get default values from DB then dynamically check some of those options.
According to the documentation, It seems like 'preferred_choices' option won't do this job.
Can anyone please help me out there?
Sorry about my English if some sentences don't make sense.
3 Tables:
UserRole
+---------+---------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------+---------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| user_id | int(11) | YES | MUL | NULL | |
| role_id | int(11) | YES | MUL | NULL | |
+---------+---------+------+-----+---------+----------------+
AdminUser
+-----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| username | varchar(25) | NO | UNI | NULL | |
| salt | varchar(32) | NO | | NULL | |
| password | varchar(40) | NO | | NULL | |
| email | varchar(60) | NO | UNI | NULL | |
| is_active | tinyint(1) | NO | | NULL | |
+-----------+-------------+------+-----+---------+----------------+
Role
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(50) | NO | UNI | NULL | |
+-------+-------------+------+-----+---------+----------------+
Form builder:
$builder->add('role', 'entity', array(
'class' => 'AcmeAdminBundle:Role',
'property' => 'name',
'multiple' => TRUE,
'expanded' => TRUE,
));

Answer 1

You must have defined a ManyToMany relation between User and Role, with some traditional methods on User entity : setRoles, getRoles, addRole...
Data that will be loaded in your form are data from a User instance, for example $user.
$user = new User; // or $user is existing User, same logic
$rolesYouWantToSetToUser = array('ROLE_1', 'ROLE_2', 'ROLE_3');
foreach ($rolesYouWantToSetToUser as $roleId) {
// $em must previsouly be set as EntityManager in your code
$role = $em->getReference('YourBundle:Role', $roleId);
$user->addRole($role);
}
// From a controller
$form = $this->createFormBuilder($user)
->add('roles', 'entity', array(
'class' => 'AcmeAdminBundle:Role',
'multiple' => true,
'expanded' => true,
'property' => 'name',
))
->getForm();