Functions: Callbacks
Using the functions described here, commands can be dynamically added to the system or be removed. You can also register and de-register functions as callbacks for any notifications.
eplRegisterCommandHandler
EplHandle
eplRegisterCommandHandler(EplSession session,
const EplChar* command,
COMMANDCALLBACK callback);
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This function provides the possibility to register external command functions via a command name.
Return |
Description |
EplHandle
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The function always returns EPL_OK.
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Input |
Type |
Description |
session
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EplSession
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Handle of the session in which the external command is to be registered.
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command
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const EplChar*
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Name under which the command function is to be registered.
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callback
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COMMANDCALLBACK*
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Pointer to the command function to be registered.
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eplUnregisterCommandHandler
EplHandle
eplUnregisterCommandHandler(const EplChar* command);
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This function removes a previously registered command from the system. Using this function commands can be written that are only to be available in certain situations.
Return |
Description |
EplHandle |
This function always returns EPL_OK. |
Input |
Type |
Description |
command |
const EplChar* |
Name of the command to be de-registered. |
eplRegisterNotificationHandler
EplHandle
eplRegisterNotificationHandler(EplSession session,
const EplChar* notification,
long clientdata,
NOTIFICATIONCALLBACK callback);
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This function allows for registering a notification handler for a certain notification. Once a handler is registered for a notification, it is called up whenever the notification is sent.
Return |
Description |
EplHandle
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The function always returns EPL_OK.
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Input |
Type |
Description |
session
|
EplSession
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Handle of the session in which the notification function is to be registered.
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notification
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const EplChar*
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Name of the notification for which the notification function is to be registered.
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clientdata
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long
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Address of user-specific data to be transferred when the notification function is called up.
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callback
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NOTIFICATIONCALLBACK
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Pointer to the notification function to be registered.
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eplUnregisterNotificationHandler
EplHandle
eplUnregisterNotificationHandler(const EplChar* notification,
NOTIFICATIONCALLBACK callback);
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This function removes a registered notification handler. The handler is then not called up for the notification any more.
Return |
Description |
EplHandle
|
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Input |
Type |
Description |
notification
|
const EplChar*
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Name of the notification whose handler is to be removed.
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callback
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NOTIFICATIONCALLBACK
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Address of the notification handler.
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