com.vaadin.shared.annotations

Annotation Type DelegateToWidget

@Target(value={METHOD,FIELD})
public @interface DelegateToWidget

Signals that the property value from a state class should be forwarded to the Widget of the corresponding connector instance.

When this annotation is present on a field or on a setter method, the framework will call the corresponding setter in the Connector's Widget instance with the current state property value whenever it has been changed. This is happens after firing com.vaadin.client.ConnectorHierarchyChangeEvents but before firing any com.vaadin.client.communication.StateChangeEvent.

Take for example a state class looking like this:

 public class MyComponentState extends AbstractComponentState {
     @DelegateToWidget
     public String myProperty;
 }
 

Whenever myProperty is changed, the framework will call code like this:

 connector.getWidget().setMyProperty(connector.getState().myProperty);
 

By default, the Widget method to call is derived from the property name, but value() in the annotation can be used to provide a custom method name, e.g. @DelegateToWidget("someSpecialName").

Since:

7.0.0

Author:

Vaadin Ltd

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	value Defines the name of the Widget method to call when the annotated state property has changed.

Element Detail

value

public abstract String value

Defines the name of the Widget method to call when the annotated state property has changed. If no value is defined, the method name will be derived from the property name, so e.g. a field named myProperty will delegate to a method named setMyProperty.

Returns:

the name of the method to delegate to, or empty string to use the default name

Default:

""