Migrating from Vaadin 6

    In Vaadin 6, a server-side component serialized its state to the client-side using the Paintable interface in the client-side and deserialized the state through the VariableOwner interface. In Vaadin 7, these are done through the ClientConnector interface.

    On the client-side, a widget deserialized its state through the Paintable interface and sent state changes through the ApplicationConnection object. In Vaadin 7, these are replaced with the ServerConnector.

    The framework ensures that the connector hierarchy and states are up-to-date when listeners are called.

    Vaadin 7 has a compatibility layer that allows quick conversion of a widget.

    1. Move the @ClientWidget(MyWidget.class) from the server-side component, say MyComponent, to the MyConnector class and make it @Connect(MyComponent.class).