groovy.beans

Annotation Type Vetoable

@Documented
@Retention(value=SOURCE)
@Target(value={FIELD,TYPE})
public @interface Vetoable

Annotates a groovy property or a class.

When annotating a property it indicates that the property should be a constrained property according to the JavaBeans spec, subject to listeners vetoing the property change.

When annotating a class it indicates that all groovy properties in that class should be bound as though each property had the annotation (even if it already has it explicitly).

It is a compilation error to place this annotation on a field (that is not a property, i.e. has scope visibility modifiers).

If a property with a user defined setter method is annotated the code block is wrapped with the needed code to fire off the event.

Here is a simple example of how to annotate a class with Vetoable:

 @groovy.beans.Vetoable
 class Person {
     String firstName
     def zipCode
 }
 

This code is transformed by the compiler into something resembling the following snippet. Notice the difference between a String and a def/Object property:

 public class Person implements groovy.lang.GroovyObject { 
     private java.lang.String firstName
     private java.lang.Object zipCode 
     final private java.beans.VetoableChangeSupport this$vetoableChangeSupport 
 
     public Person() {
         this$vetoableChangeSupport = new java.beans.VetoableChangeSupport(this)
     }
 
     public void addVetoableChangeListener(java.beans.VetoableChangeListener listener) {
         this$vetoableChangeSupport.addVetoableChangeListener(listener)
     }
 
     public void addVetoableChangeListener(java.lang.String name, java.beans.VetoableChangeListener listener) {
         this$vetoableChangeSupport.addVetoableChangeListener(name, listener)
     }
 
     public void removeVetoableChangeListener(java.beans.VetoableChangeListener listener) {
         this$vetoableChangeSupport.removeVetoableChangeListener(listener)
     }
 
     public void removeVetoableChangeListener(java.lang.String name, java.beans.VetoableChangeListener listener) {
         this$vetoableChangeSupport.removeVetoableChangeListener(name, listener)
     }
 
     public void fireVetoableChange(java.lang.String name, java.lang.Object oldValue, java.lang.Object newValue) throws java.beans.PropertyVetoException {
         this$vetoableChangeSupport.fireVetoableChange(name, oldValue, newValue)
     }
 
     public java.beans.VetoableChangeListener[] getVetoableChangeListeners() {
         return this$vetoableChangeSupport.getVetoableChangeListeners()
     }
 
     public java.beans.VetoableChangeListener[] getVetoableChangeListeners(java.lang.String name) {
         return this$vetoableChangeSupport.getVetoableChangeListeners(name)
     }
 
     public void setFirstName(java.lang.String value) throws java.beans.PropertyVetoException {
         this.fireVetoableChange('firstName', firstName, value)
         firstName = value 
     }
 
     public void setZipCode(java.lang.Object value) throws java.beans.PropertyVetoException {
         this.fireVetoableChange('zipCode', zipCode, value)
         zipCode = value 
     }
 }
 

Author:

Danno Ferrin (shemnon)

See Also:

VetoableASTTransformation