Question

In an arbitrary JavaScript function, I wish to determine the upstream event.

The event listener function did not pass the event do the current function. As far as I know, window.event is not WC3 and not available.

function listener(e) { subfunc(e.target); }

function subfunc( element) {
    // here I wish to know which if any event responsible for me being called
    var event = ?;
    switch( event.type ) { ... }
}

How does function subfunc() determine the current event?

(Apologize if question asked before – seems it must have been – but cannot track it down.)

Answer 1

You can do:

function listener(e) { subfunc.call(this, e); }

function subfunc( e ) {
    var element = this; //<- 'this' points to your element, 'e.type' is event type
    switch( e.type ) { ... }
}

Also other way:

function listener(e) { subfunc.call(e, e.target); }

function subfunc( element ) {
    var event = this; //<- 'this' points to your event object
    switch( event.type ) { ... }
}