These functions are for registering callbacks on Shiny session events.
onFlush registers a function that will be called before Shiny flushes
the reactive system. onFlushed registers a function that will be
called after Shiny flushes the reactive system. onSessionEnded
registers a function to be called after the client has disconnected.
onFlush(fun, once = TRUE, session = getDefaultReactiveDomain())onFlushed(fun, once = TRUE, session = getDefaultReactiveDomain())
onSessionEnded(fun, session = getDefaultReactiveDomain())
A callback function.
Should the function be run once, and then cleared, or should it
re-run each time the event occurs. (Only for onFlush and
onFlushed.)
A shiny session object.
These functions should be called within the application's server function.
All of these functions return a function which can be called with no arguments to cancel the registration.
onStop() for registering callbacks that will be
invoked when the application exits, or when a session ends.