gupnp_device_action_callback_set Set device callback function &reftitle.description; boolgupnp_device_action_callback_set resourceroot_device intsignal stringaction_name mixedcallback mixedarg Set device callback function for signal and action. &reftitle.parameters; root_device A root device identifier, returned by gupnp_root_device_new. signal The value of signal. Signal can be one of the following values: GUPNP_SIGNAL_ACTION_INVOKED Emitted whenever an action is invoked. Handler should process action and must call either gupnp_service_action_return or gupnp_service_action_return_error. GUPNP_SIGNAL_NOTIFY_FAILED Emitted whenever notification of a client fails. action_name The name of action. callback The callback function for the certain signal. Typically, callback function takes on three parameters. The service parameter's identifier being the first, action parameter's identifier (in case GUPNP_SIGNAL_ACTION_INVOKED signal) or error parameter's message (in case GUPNP_SIGNAL_NOTIFY_FAILED signal) being the second, and the arg is third. arg User data for callback. &reftitle.returnvalues; &return.success; &reftitle.errors; Issues E_WARNING either with not valid callback function or with not valid signal. &reftitle.seealso; gupnp_root_device_new