Every session creating and closing starts and commits the model editing transaction. The com.nomagic.uml2.transaction.TransactionCommitListener is a special listener, which is notified when the all changes inside a transaction are done and the transaction is closed.

The TransactionCommitListener contains transactionCommited(java.util.Collection<java.beans.PropertyChangeEvent>) method, which provides a collection of all java.beans.PropertyChangeEvent(s) that were executed in a transaction.


Create a custom transaction commit listener:


    public class MyTransactionListener implements TransactionCommitListener
    {
        public Runnable transactionCommited(final Collection<PropertyChangeEvent> events)
        {
            return new Runnable()
            {
                public void run()
                {
                    for (PropertyChangeEvent event : events)
                    {
                        if (UML2MetamodelConstants.INSTANCE_CREATED.equals(event.getPropertyName()))
                        {
                            Object source = event.getSource();
                            if (source instanceof Property)
                            {
                                Property property = (Property) source; Element owner = property.getOwner();
                                if (owner instanceof Classifier)
                                {
                                    Classifier propertyOwner = (Classifier) owner;
                                    propertyOwner.setName("Contains (" + propertyOwner.getAttribute().size() + ") attributes");
                                }

 
                                // additionally for this Property we register listener to listen for any property changes in this Element properties.
                                property.addPropertyChangeListener(new DerivedValuePropertyChangeListener());
                            }
                        }
                    }
                }
            };
       }
    }


This “transaction commit listener” checks, if a new property is created in a classifier and updates the classifier’s (a property owner) name. All changes are done in the same session.

Register the custom “transaction commit listener” into the project

    MyTransactionListener transactionListener = new MyTransactionListener(); 
    TransactionManager transactionManager = project.getRepository().getTransactionManager();
    transactionManager.addTransactionCommitListener(transactionListener);
Related pages