# Interface DataChannelListener

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

  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 Details

  - ### 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.