How to detect `focusin` support?

Question

Thanks to Perfection kills, we can use the following JavaScript to detect event support:

function hasEvent(ev) {
    var elem = document.createElement(\'a\'),         


        

Answer 1

focusin & focusout should be fired BEFORE target element receives focus, event order is also seems buggy

http://www.w3.org/TR/DOM-Level-3-Events/#events-focusevent-event-order

currently, only IE works according to spec:

Chrome/Safari:
focus
focusin
DOMFocusIn
blur
focusout
DOMFocusOut
focus
focusin
DOMFocusIn

Opera 12:
focus
DOMFocusIn
focusin
blur
DOMFocusOut
focusout
focus
DOMFocusIn
focusin

IE 8:
focusin
focus
focusout
focusin
blur
focus

Firefox 14:
focus
blur
focus