CODEWITHSUNDEEP
javascriptinternet-explorereventsmootoolspreventdefault
sv_in
sv_in

Reputation: 14039

event.preventDefault() function not working in IE

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?

Upvotes: 208

Views: 216358

Answers (11)

Pablo
Pablo

Reputation: 586

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;
}

Upvotes: 0

EliuX
EliuX

Reputation: 12625

preventDefault is a widespread standard; using an adhoc every time you want to be compliant with old IE versions is cumbersome, better to use a polyfill:

if (typeof Event.prototype.preventDefault === 'undefined') {
    Event.prototype.preventDefault = function (e, callback) {
        this.returnValue = false;
    };
}

This will modify the prototype of the Event and add this function, a great feature of javascript/DOM in general. Now you can use e.preventDefault with no problem.

Upvotes: 2

oldwizard
oldwizard

Reputation: 5062

If you bind the event through mootools' addEvent function your event handler will get a fixed (augmented) event passed as the parameter. It will always contain the preventDefault() method.

Try out this fiddle to see the difference in event binding. http://jsfiddle.net/pFqrY/8/

// preventDefault always works
$("mootoolsbutton").addEvent('click', function(event) {
 alert(typeof(event.preventDefault));
});

// preventDefault missing in IE
<button
  id="htmlbutton"
  onclick="alert(typeof(event.preventDefault));">
  button</button>

For all jQuery users out there you can fix an event when needed. Say that you used HTML onclick=".." and get a IE specific event that lacks preventDefault(), just use this code to get it.

e = $.event.fix(e);

After that e.preventDefault(); works fine.

Upvotes: 23

Alsciende
Alsciende

Reputation: 26971

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);

Upvotes: 480

KWallace
KWallace

Reputation: 1698

FWIW, in case anyone revisits this question later, you might also check what you are handing to your onKeyPress handler function.

I ran into this error when I mistakenly passed onKeyPress(this) instead of onKeyPress(event).

Just something else to check.

Upvotes: 0

daemon1981
daemon1981

Reputation: 246

return false in your listener should work in all browsers.

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

Upvotes: 0

muffir
muffir

Reputation: 447

I know this is quite an old post but I just spent some time trying to make this work in IE8.

It appears that there are some differences in IE8 versions because solutions posted here and in other threads didn't work for me.

Let's say that we have this code:

$('a').on('click', function(event) {
    event.preventDefault ? event.preventDefault() : event.returnValue = false;
});

In my IE8 preventDefault() method exists because of jQuery, but is not working (probably because of the point below), so this will fail.

Even if I set returnValue property directly to false:

$('a').on('click', function(event) {
    event.returnValue = false;
    event.preventDefault();
});

This also won't work, because I just set some property of jQuery custom event object.

Only solution that works for me is to set property returnValue of global variable event like this:

$('a').on('click', function(event) {
    if (window.event) {
        window.event.returnValue = false;
    }
    event.preventDefault();
});

Just to make it easier for someone who will try to convince IE8 to work. I hope that IE8 will die horribly in painful death soon.

UPDATE:

As sv_in points out, you could use event.originalEvent to get original event object and set returnValue property in the original one. But I haven't tested it in my IE8 yet.

Upvotes: 12

JBE
JBE

Reputation: 12597

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

Upvotes: 4

user175353
user175353

Reputation:

Here's a function I've been testing with jquery 1.3.2 and 09-18-2009's nightly build. Let me know your results with it. Everything executes fine on this end in Safari, FF, Opera on OSX. It is exclusively for fixing a problematic IE8 bug, and may have unintended results:

function ie8SafePreventEvent(e) {
    if (e.preventDefault) {
        e.preventDefault()
    } else {
        e.stop()
    };

    e.returnValue = false;
    e.stopPropagation();
}

Usage:

$('a').click(function (e) {
    // Execute code here
    ie8SafePreventEvent(e);
    return false;
})

Upvotes: 3

RolandoCC
RolandoCC

Reputation: 878

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

Tested on IE 9 and Chrome.

Upvotes: 5

Alsciende
Alsciende

Reputation: 26971

Mootools redefines preventDefault in Event objects. So your code should work fine on every browser. If it doesn't, then there's a problem with ie8 support in mootools.

Did you test your code on ie6 and/or ie7?

The doc says

Every event added with addEvent gets the mootools method automatically, without the need to manually instance it.

but in case it doesn't, you might want to try

new Event(event).preventDefault();

Upvotes: 6

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