Provider Broadcasts

When coding applications like auctions, sometimes it is necessary to have ASTA servers "push" out information with it being directly requested from ASTA clients. TAstaProviders provide a way to do just this with little or no code.

TAstaProviders can be used to allow remote ASTA clients to be notified of any changes to any table. When using a TAstaClientDataSet, instead of using SQL, choose a Provider by pulling down the ProviderName property. Then click on the ProviderBroadcast property and set the RegisterForBroadcast property to True. If you want the AstaClientDataSet to be editable set the SQLGenerateLocation to gsServer.

When the TAstaClientDataSet is opened, it will fetch any results from the TDataSet attached to the provider on the server and also internally call RegisterProviderForUpdates which registers that TDataSet to receive notification when any other TAstaClientDataSet makes any changes to that TDataSet attached to the TAstaProvider on the server.

Any changes will be broadcast from the server side TAstaProvider and recieved in the TAstaClientDataSet.OnProviderBroadCast event. Providers can limit broadcast to specific row criteria by coding the AstaProvider.OnBroadCastDecideEvent. Providers can be networked to allow them to broadcast to all connected clients using the same TAstaProvider.UpdateTableName by calling

TAstaServerSocket.NetWorkProviderBroadcast