Extending existing Class in Symfony - symfony

Question

I am new to symfony. I have created a registration form using the code:
$user = new Register();
$form = $this->createForm(new RegisterType(), $user);
In the RegisterType class i have 5 fields (for example).I store the values in database when the user registers with the system. Now I display the EDIT page using following code:
$user = $em->getRepository('MysiteUserBundle:Register')->find($id);
$form = $this->createForm(new RegisterType(), $user);
//edit.html.twig code
<form action="{{ path('MysiteUserBundle_register_update',{'id':user.id}) }}" method="post" {{ form_enctype(form) }} class="register">
{{ form_errors(form) }}
{{ form_row(form.firstname) }}
{{ form_row(form.lastname) }}
{{ form_row(form.username) }}
<p>
<input type="submit" value="Submit">
</p>
</form>
The problem with the EDIT code however is that it displays me all of the fields mentioned in RegisterType class.Is it possible to display only some fields. If yes how can this be achieved. Any help will be appreciated

Answer 1

It doesn't make sense to use the registration form type to edit a user, because registration happens once per user. Instead you could create another form type with only those fields you need when editing a user. One can extend the other to avoid duplication.
You could also:
Keep just one form type but add some fields conditionally — that is, only when the entity is new. You can get your entity in the form type as $options['data'] and check if its ID is not null or whatever.
Use form events.