Package com.smartgwt.client.widgets.grid.events

# Interface GroupByHandler

All Superinterfaces:
  `EventHandler`

public interface GroupByHandler extends EventHandler

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `onGroupBy(GroupByEvent event)`
  Callback fired when the user attempts to group or ungroup the listGrid, or when `groupBy()` is called programmatically.

- ## Method Details

  - ### onGroupBy

    void onGroupBy(GroupByEvent event)
    Callback fired when the user attempts to group or ungroup the listGrid, or when `groupBy()` is called programmatically. This event may be cancelled.

    This notification is fired before the `data` is updated to reflect the grouping. See also `ListGrid.groupByComplete()`.

    Note that this method is not called when the data is regrouped, either `programmatically`, or in response to new data arriving from the server, and such regrouping can't be canceled - instead use callback `ListGrid.regroup()`.

    Parameters:
      `event` - the event