Spring - form with 2 modelAttributes - spring

Question

I know how to use a form with 1 modelAttribute but how should I set 2 model attributes in same form ?
I have:
<sf:form id="details" action="/updateuser" method="POST" modelAttribute="updateuser">
<sf:input type="text" name="firstName" path="firstName"/></br>
<sf:input type="text" name="lastName" path="lastName" /></br>
<sf:input type="text" name="email" path="email" /><sf:errors path="email" cssClass="error"></sf:errors> </br>
<sf:input type="text" name="facebook" path="facebook" /> </br>
<sf:input type="text" name="twitter" path="twitter" /> </br>
</sf:form>
firstName lastName and email are for modelAttribute="updateuser" but I need another modelAttribute for facebook and twitter
How should I implement this ?
Thanks!
EDIT:
Isn't there any other way to do this without a wrapper class ? For more info, I have:
class User {
private String firstName;
private String lastName;
private String email;
}
class SocialMedia {
private String facebook;
private String twitter;
}

Answer 1

You can't attach more than one object to the <form>. However, you can create an explicit model class for the form and attach it.
class UpdateUserFormModel {
private Updateuser updateuser;
private Facebook facebook;
private Twitter twitter;
}
You can access nested objects using . operator
<sf:input type="text" name="firstName" path="updateuser.firstName"/></br>
<sf:input type="text" name="facebook" path="facebook" /> </br>

Answer 2

No you can't have more than one model attribute for one form, but you can use a wrapper to wrap your models.
class Wrapper {
private Class1 c1;
private Class2 c2;
....
//getter&setters
}
However, you are allowed to bind several objects to the same model using
model.addObject("objectName",object);
and access the objects in your page by
${objectName.name }