event.preventDefault() function not working in IE

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?

Solutions/Answers:

Solution 1:

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);

Solution 2:

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.

Related:  AngularJS Authentication + RESTful API

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.

Solution 3:

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.

Related:  How to represent arrays within ember-data models?

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.

Solution 4:

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();

Solution 5:

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

Tested on IE 9 and Chrome.

Related:  Get month name from Date

Solution 6:

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