Data Access Modes > User Events Mode > Implementing Handlers for User Events Mode |
The most essential part of defining your custom data source is, of course, programming handlers for the True DataControl events: UserReadData, UserWriteData, UserAddData, UserDeleteRow, and UserFindData. Depending upon your application requirements, you may not have to provide handlers for all five events. For example, if your data source is read-only, implementing UserReadData alone is sufficient. The UserFindData event is optional in all cases, it is only used to improve search performance in large data sources.
See the Reference section for details on each of the following events used in the user events mode:
Fired when the control is requested to retrieve a bookmark or columns data. |
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Fired when a row data has been modified and the user commits the changes by leaving the row or calling Recordset.Update. |
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Fired when a new row has been added and the user commits the changes by leaving the newly added row or calling Recordset.Update. |
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Fired when a row has been deleted and the user commits the changes. |
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Gives you an opportunity to optimize performance of simple search in your data source. |