groovy.beans

## Annotation Type Vetoable

    @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`