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Load Delay

When you anticipate that many rapid changes that will trigger an AutoLoad may occur, you can use the LoadDelay property of the control.

Imagine that the user is typing a word in a search text-box and that this search text-box is connected with a FilterDescriptor.Value on the RadDataServiceDataSource control. Normally, each letter typed would send an asynchronous request to the server, but that is not very effective. A more effective approach would be to let the user type the search criteria and when he is done simply send on request to the server.

The LoadDelay property represents a time-span. The control will “wait” one LoadDelay amount of time before it sends an AutoLoad request to the server. Multiple changes that occur within the specified time span are aggregated into a single Load operation. For every change that occurs, the delay timer is reset. This allows many changes to be combined into a single call as long as each change occurs within the specified delay from the last. Once the delay timer is allowed to elapse without a change occurring, Load will be invoked. This for example could be our user typing his last letter in the search criteria text-box and then doing nothing for a little while.