[removed]: Is it possible to get any details about how the window was unloaded?

Question

I\'m developing one of those warning windows that tells the user that they may have unsaved data, but I only need it to warn them if they\'re leaving the page. Currently it

Answer 1

I was running into a simular issue when a user was hitting enter from an input field on a form. The form was being submitted thus firing off the onbeforeunload event. I tried setting a flag to avoid showing the message on the keydown event on the input, filtering on the enterkey code. This wasn't getting triggered until after the onbeforeunload event was firing and therefore the flag wasn't getting set.

I then looked into the _EVENTTARGET as jbabey suggested. If the form was being submitted there would be a value in that field, if it was being refreshed there wouldn't.

Therefore, doing a simple check to see if there was value in the _EVENTARGET field in the onbeforeunload event could determine if the input from the form was causing the postback.

Here is my code.

            window.onbeforeunload = function (e) {
            if ($('[id$=__EVENTTARGET]').val().indexOf('btnValidateMaterials') != -1) {
                confirmExit = false;
            }

            if (DateOrQtyHasChanged() && confirmExit) {

                if (/Firefox[\/\s](\d+)/.test(navigator.userAgent) && new Number(RegExp.$1) >= 4) {
                    var message = $('[id$=hfLeaveMessageFF]').val();
                    if (confirm(message)) {
                        history.go();
                    }
                    else {
                        window.setTimeout(function () {
                            window.stop();
                        }, 1);
                    }
                }
                else {
                    var message = $('[id$=hfLeaveMessage]').val();
                    return message;
                }
            }
        }