Microsoft Internet Security and Acceleration Server 2004 SDK

ReloadWpxFilterConfiguration

The ReloadWpxFilterConfiguration function receives a notification from the Web proxy that changes to the configuration of the ISA Server administration COM objects have been applied in a call to a Save method. You can use this function to perform operations to update the Web filter by reloading the saved configuration of the ISA Server administration COM objects from persistent storage.

Note  The configuration used by the ISA Server services is only updated by the Save method when its fReloadConfiguration parameter is set to VARIANT_TRUE.

This function declaration is:

BOOL WINAPI ReloadWpxFilterConfiguration(void);

Parameters

This callback has no parameters.

Return Values

The implementation of this function should return TRUE if the filter is successfully updated with respect to changes in the stored ISA Server configuration or FALSE if reloading of any part of the configuration fails. If a failure occurs, the filter must call SetLastError with the nature of the failure before returning FALSE.

Remarks

ISA Server 2004 provides a new mechanism to enable filters to be updated when changes are made to objects in ISA Server storage. In ISA Server 2000, you would register your filter to receive notifications about changes to specific objects, but the filter had no means of indicating whether it had recognized the change. The new mechanism provides a means of indicating to the user whether changes were successfully applied (reloaded by the ISA Server services, application filters, and Web filters). If not, an event can be written to the event log.

A call to a Save method with the fReloadConfiguration parameter set to VARIANT_TRUE ensures only that configuration changes that can be applied dynamically take effect without restarting services. Changes that require restarting of the Firewall service are applied during a call to a Save method only if the fResetRequiredServices parameter is set to VARIANT_TRUE. For more information, see Restarting Services after Configuration Changes.

The Microsoft Firewall service notifies the Web proxy after it has reloaded the saved configuration with the most recent changes from persistent storage to the ISA Server services. The Web proxy then calls ReloadWpxFilterConfiguration in each registered Web filter after it has reloaded the most recent changes from persistent storage.

When this function returns FALSE, the Web proxy can pass the error back to the Firewall service. If the Save method was invoked because the user pressed the Apply button in ISA Server Management and the ReloadWpxFilterConfiguration method returns FALSE, the Firewall service will display a message to the user in ISA Server Management that the reload operation failed and will direct the user to look in the event log for details about the failure. When you implement this function in a Web filter, you should make sure that the filter writes the error code and a specific description in the event log with details about the part of the configuration that failed to reload.

Requirements

Server: Requires Windows Server 2003 or Windows 2000.
Version: Requires Internet Security and Acceleration Server 2004.
Header: Declared in Wpxhttpfilt.h.

See Also

Entry-Point Functions