(PECL gupnp >= 0.1.0)
gupnp_service_proxy_add_notify — Sets up callback for variable change notification
Sets up callback to be called whenever a change notification for variable is recieved.
A service proxy identifier.
The variable to add notification for.
The type of the variable. Type can be one of the following values:
The callback to call when variable changes. Typically, callback function takes on three parameters. The variable parameter being the first, value parameter being the second, and the arg is third.
User data for callback.
成功时返回 TRUE, 或者在失败时返回 FALSE.