A complete overview of what needs to be done

Here is a complete overview of what needs to be done. I have listed the different sources found here and there at the end of this post.

1. Override setter in Acme\UserBundle\Entity\User

public function setEmail($email)
{
    $email = is_null($email) ? '' : $email;
    parent::setEmail($email);
    $this->setUsername($email);

    return $this;
}

2. Remove the username field from your form type

(in both RegistrationFormType and ProfileFormType)

public function buildForm(FormBuilder $builder, array $options)
{
    parent::buildForm($builder, $options);
    $builder->remove('username');  // we use email as the username
    //..
}

3. Validation constraints

As shown by @nurikabe, we have to get rid of the validation constraints provided by FOSUserBundle and create our own. This means that we will have to recreate all the constraints that were previously created in FOSUserBundle and remove the ones that concern the username field. The new validation groups that we will be creating are AcmeRegistration and AcmeProfile. We are therefore completely overriding the ones provided by the FOSUserBundle.

3.a. Update config file in Acme\UserBundle\Resources\config\config.yml

fos_user:
    db_driver: orm
    firewall_name: main
    user_class: Acme\UserBundle\Entity\User
    registration:
        form:
            type: acme_user_registration
            validation_groups: [AcmeRegistration]
    profile:
        form:
            type: acme_user_profile
            validation_groups: [AcmeProfile]

3.b. Create Validation file Acme\UserBundle\Resources\config\validation.yml

That’s the long bit:

Acme\UserBundle\Entity\User:
    properties:
    # Your custom fields in your user entity, here is an example with FirstName
        firstName:
            - NotBlank:
                message: acme_user.first_name.blank
                groups: [ "AcmeProfile" ]
            - Length:
                min: 2
                minMessage: acme_user.first_name.short
                max: 255
                maxMessage: acme_user.first_name.long
                groups: [ "AcmeProfile" ]



# Note: We still want to validate the email
# See FOSUserBundle/Resources/config/validation/orm.xml to understand
# the UniqueEntity constraint that was originally applied to both
# username and email fields
#
# As you can see, we are only applying the UniqueEntity constraint to 
# the email field and not the username field.
FOS\UserBundle\Model\User:
    constraints:
        - Symfony\Bridge\Doctrine\Validator\Constraints\UniqueEntity: 
             fields: email
             errorPath: email 
             message: fos_user.email.already_used
             groups: [ "AcmeRegistration", "AcmeProfile" ]

    properties:
        email:
            - NotBlank:
                message: fos_user.email.blank
                groups: [ "AcmeRegistration", "AcmeProfile" ]
            - Length:
                min: 2
                minMessage: fos_user.email.short
                max: 255
                maxMessage: fos_user.email.long
                groups: [ "AcmeRegistration", "ResetPassword" ]
            - Email:
                message: fos_user.email.invalid
                groups: [ "AcmeRegistration", "AcmeProfile" ]
        plainPassword:
            - NotBlank:
                message: fos_user.password.blank
                groups: [ "AcmeRegistration", "ResetPassword", "ChangePassword" ]
            - Length:
                min: 2
                max: 4096
                minMessage: fos_user.password.short
                groups: [ "AcmeRegistration", "AcmeProfile", "ResetPassword", "ChangePassword"]

FOS\UserBundle\Model\Group:
    properties:
        name:
            - NotBlank:
                message: fos_user.group.blank
                groups: [ "AcmeRegistration" ]
            - Length:
                min: 2
                minMessage: fos_user.group.short
                max: 255
                maxMessage: fos_user.group.long
                groups: [ "AcmeRegistration" ]

FOS\UserBundle\Propel\User:
    properties:
        email:
            - NotBlank:
                message: fos_user.email.blank
                groups: [ "AcmeRegistration", "AcmeProfile" ]
            - Length:
                min: 2
                minMessage: fos_user.email.short
                max: 255
                maxMessage: fos_user.email.long
                groups: [ "AcmeRegistration", "ResetPassword" ]
            - Email:
                message: fos_user.email.invalid
                groups: [ "AcmeRegistration", "AcmeProfile" ]

        plainPassword:
            - NotBlank:
                message: fos_user.password.blank
                groups: [ "AcmeRegistration", "ResetPassword", "ChangePassword" ]
            - Length:
                min: 2
                max: 4096
                minMessage: fos_user.password.short
                groups: [ "AcmeRegistration", "AcmeProfile", "ResetPassword", "ChangePassword"]


FOS\UserBundle\Propel\Group:
    properties:
        name:
            - NotBlank:
                message: fos_user.group.blank
                groups: [ "AcmeRegistration" ]
            - Length:
                min: 2
                minMessage: fos_user.group.short
                max: 255
                maxMessage: fos_user.group.long
                groups: [ "AcmeRegistration" ]

4. End

That’s it! You should be good to go!

Documents used for this post:

• Best way to remove usernames from FOSUserBundle
• [Validation] Doesn’t override properly
• UniqueEntity
• Validating fosuserbundle registration form
• How to use validation groups in Symfony
• Symfony2 using validation groups in form