Tells the server component whether to attempt to maintain its state by saving the retrieved data and leaving the transaction open. Keeping the retrieved data means that the component does not need to reconnect and retrieve data every time a method is called.
When the Web DataWindow is running as an EAServer component, you must call SetServerSideState if you want the component to save state information. In other server environments, you only need to keep a reference to the component in the session object of the page server. The server component will attempt to keep the retrieved data available until ServerSideState is set to false or the server component goes away.
DataWindow type |
Method applies to |
|---|---|
Web |
Server component |
Web DataWindow server component
string dwcomponent.SetServerSideState ( boolean maintainstate )
Argument |
Description |
|---|---|
dwcomponent |
A reference to a Web DataWindow server component |
maintainstate |
Specifies whether the server will attempt to maintain its state between method calls. Values are:
|
Returns an empty string if it succeeds and an error message from EAServer if it fails.
The Web DataWindow can run in a fully stateless server environment. Variables in the Web page keep information about the rows being viewed and changes the user makes and this information is communicated to the server component as needed so the component can restore its state each time it is called. Restoring its state includes retrieving data from the database each time the page is reloaded, including each time the user navigates to another page.
Operating in a stateless mode minimizes use of server resources but can decrease performance. The client maintains the state of the server component in string form and the information is sent back and forth with every request. Also, when state is not maintained on the server, the component must connect to the database and retrieve data each time it is called. If the component server does not do connection caching, response time for the client could be very slow.
You can increase performance by maintaining state on the server. To maintain state, the page server’s session object keeps a reference to the server component. If the server component is running in EAServer, you must also mark the component as a stateful object. You can do this by calling SetServerSideState or by setting the component’s serverSideState property in EAServer Manager.
Maintaining state on the server will provide faster response time if the same component is accessed again. However, it also increases the server resources used for each client connection.
To minimize impact on server resources, a short timeout on a session lets the server get rid of a component that might not be requested again. If the component is called again, its state can be restored from the client state information.
You can also increase performance by calling Update frequently.
For information about using the Web DataWindow, see the DataWindow Programmers Guide.
This example specifies that the EAServer component should maintain state:
webDW.SetServerSideState( true );
