com.smartgwt.client.widgets.tree.events

## Interface HasDataChangedHandlers

- All Superinterfaces:
    com.google.gwt.event.shared.HasHandlers

      public interface HasDataChangedHandlers
      extends com.google.gwt.event.shared.HasHandlers

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `com.google.gwt.event.shared.HandlerRegistration` | `addDataChangedHandler(DataChangedHandler handler)` Notification method fired when the TreeGrid's data changes, for any reason.

    - ### Methods inherited from interface com.google.gwt.event.shared.HasHandlers

      `fireEvent`

- - ### Method Detail

    - #### addDataChangedHandler

          com.google.gwt.event.shared.HandlerRegistration addDataChangedHandler(DataChangedHandler handler)

      Notification method fired when the TreeGrid's data changes, for any reason.

      Examples of why data changed might be:

      - a call to `addData`, `updateData`, or `removeData`
      - `DataSource` updates from the server for `ResultTree` data (triggered by record editing, etc.)
      - fetches arriving back from the server for `ResultTree` data
      - programmatic changes to `Tree` data if made through APIs such as `Tree.add()`, `Tree.remove()`, etc.
      - cache invalidation
      - filtering
      Calling `setData()` doesn't call this notification directly, but it may fire if one of the above listed events is triggered (e.g. a server fetch for `ResultTree` data).

      Note that the `operationType` parameter is optional and will be passed and contain the operation (e.g. "update") if this notification was triggered by a fetch, an `addData`, `updateData`, or `removeData`, or a `DataSource` update for `ResultTree` data (the first three reasons listed above) but otherwise will be null.

      Parameters:
        `handler` - the dataChanged handler
      Returns:
        `HandlerRegistration` used to remove this handler