event.preventDefault() function not working in IE

Question

Following is my JavaScript (mootools) code:

$('orderNowForm').addEvent('submit', function (event) {
    event.preventDefault();
    allFilled = false;
    $$(".required").each(function (inp) {
        if (inp.getValue() != '') {
            allFilled = true;
        }
    });

    if (!allFilled) {
        $$(".errormsg").setStyle('display', '');
        return;
    } else {
        $$('.defaultText').each(function (input) {
            if (input.getValue() == input.getAttribute('title')) {
                input.setAttribute('value', '');
            }
        });
    }

    this.send({
        onSuccess: function () {
            $('page_1_table').setStyle('display', 'none');
            $('page_2_table').setStyle('display', 'none');
            $('page_3_table').setStyle('display', '');
        }
    });
});

In all browsers except IE, this works fine. But in IE, this causes an error. I have IE8 so while using its JavaScript debugger, I found out that the event object does not have a preventDefault method which is causing the error and so the form is getting submitted. The method is supported in case of Firefox (which I found out using Firebug).

Any Help?

Answer 1

I was helped by a method with a function check. This method works in IE8

if(typeof e.preventDefault == 'function'){
  e.preventDefault();
} else {
  e.returnValue = false;
}

Answer 2

in IE, you can use

event.returnValue = false;

to achieve the same result.

And in order not to get an error, you can test for the existence of preventDefault:

if(event.preventDefault) event.preventDefault();

You can combine the two with:

event.preventDefault ? event.preventDefault() : (event.returnValue = false);

Answer 3

return false in your listener should work in all browsers.

$('orderNowForm').addEvent('submit', function () {
    // your code
    return false;
}

Answer 4

To disable a keyboard key after IE9, use : e.preventDefault();

To disable a regular keyboard key under IE7/8, use : e.returnValue = false; or return false;

If you try to disable a keyboard shortcut (with Ctrl, like Ctrl+F) you need to add those lines :

try {
    e.keyCode = 0;
}catch (e) {}

Here is a full example for IE7/8 only :

document.attachEvent("onkeydown", function () {
    var e = window.event;

    //Ctrl+F or F3
    if (e.keyCode === 114 || (e.ctrlKey && e.keyCode === 70)) {
        //Prevent for Ctrl+...
        try {
            e.keyCode = 0;
        }catch (e) {}

        //prevent default (could also use e.returnValue = false;)
        return false;
    }
});

Reference : How to disable keyboard shortcuts in IE7 / IE8

Answer 5

if (e.preventDefault) {
    e.preventDefault();
} else {
    e.returnValue = false;
}

Tested on IE 9 and Chrome.