DataChannelListener (cayenne-doc: Cayenne Documentation 4.2 API)

```
public interface DataChannelListener
```
A listener of DataChannel lifecycle events. Changes related to an event are attached as a GraphDiff. If a listener needs to process these changes, the easiest way to do that is via GraphChangeHandler "visitor":
```
   public void graphChanged(GraphEvent event) {
       GraphChangeHandler handler = ..;
       event.getDiff().apply(handler);
   }
 
```
Since:

1.2

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`graphChanged(GraphEvent event)`	Notifies implementing object of the changes that were performed to the object graph externally, not by one of the channel ObjectContexts.
`void`	`graphFlushed(GraphEvent event)`	Notifies implementing object that one of the channel ObjectContexts flushed its changes to the channel.
`void`	`graphRolledback(GraphEvent event)`	Notifies implementing object that one of the channel ObjectContexts initiated a rollback.

- Method Detail
  - graphChanged
```
void graphChanged(GraphEvent event)
```
    Notifies implementing object of the changes that were performed to the object graph externally, not by one of the channel ObjectContexts.
  - graphFlushed
```
void graphFlushed(GraphEvent event)
```
    Notifies implementing object that one of the channel ObjectContexts flushed its changes to the channel.
  - graphRolledback
```
void graphRolledback(GraphEvent event)
```
    Notifies implementing object that one of the channel ObjectContexts initiated a rollback.