How to: Work with Events and Program Business Logic

This topic describes how to work with events and business logic in Sync Framework. The examples in this topic focus on the following Sync Framework types and events:

For information about how to run sample code, see "Example Applications in the How to Topics" in Programming Common Client and Server Synchronization Tasks.

Understanding Database Provider Events

Sync Framework provides many events that expose both data and metadata that you can use during synchronization. For example, the SchemaCreatedEventArgs object provides access to the SyncSchema object for each table that was created in the client database, and also the connection and transaction over which the schema was created. This enables you to make schema changes through the API, within the same transaction as the client synchronization provider.

The time at which an event is raised is appropriate to its use, as you can see in the following examples:


The example code in this topic shows you how to respond to Sync Services events by displaying synchronization progress to the screen, logging event-related data for applied and failed changes, and changing data during synchronization to enforce business logic. Instead of breaking this example into code examples, it is more useful to run the sample code, and to see what data is displayed and logged for each event by the EventLogger and SampleStatsAndProgress classes. However, before you run the sample code, we recommend that you look at the following code example.

Performing Business Logic During Synchronization

This example shows the control that you have over data during synchronization. It shows you how to access the set of changes before it is applied at the server by handling the server-side ApplyingChanges event. The example also shows you how you can introduce logic for the client-side event. In this case a column is updated. However, you could easily perform an inventory check, or any other business logic that an application requires, before changes are committed at the server or client. For examples of how you can do this when data conflicts occur, see How to: Handle Data Conflicts and Errors.

Complete Code Example

The following complete code example requires the Utility class that is available in Utility Class for Database Provider How-to Topics.

See Also


Programming Common Client and Server Synchronization Tasks