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How can I prevent Backspace from navigating back in javascript?

Tags:

javascript

This works in IE, but I cannot get it to work in Opera or Firefox. I want to prevent Backspace from navigating away if and only if the current focus is the SELECT dropdown.

<html>
<body>
<select id="testselect">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
</select>
<script language="javascript">
    document.getElementById("testselect").onkeydown = function(e) {
        if(!e) {
            e = event;
        }
        alert(e.keyCode);
        if (e.keyCode == 8 || e.keyCode == 46) {
       e.returnValue = false;

        e.cancelBubble = true;
        if (e.stopPropagation) { e.stopPropagation(); alert("stoppropagation");}
        if (e.preventDefault) { e.preventDefault(); alert("preventdefault");}
        return false;
        }
    };
</script>
</body>
</html>
like image 950
hova Avatar asked Nov 20 '09 20:11

hova


1 Answers

Using jquery - for only select dropdown

$(document).ready(function(){ 
     //for IE use keydown, for Mozilla keypress  
     //as described in scr: http://www.codeproject.com/KB/scripting/PreventDropdownBackSpace.aspx
     $('select').keypress(function(event){if (event.keyCode == 8) {return false;}});
     $('select').keydown(function(event){if (event.keyCode == 8) {return false;}});
}

For all elements in page except input controls and textarea is as follows

<script type="text/javascript">

    //set this variable according to the need within the page
    var BACKSPACE_NAV_DISABLED = true;

    function fnPreventBackspace(event){if (BACKSPACE_NAV_DISABLED && event.keyCode == 8) {return false;}}
    function fnPreventBackspacePropagation(event){if(BACKSPACE_NAV_DISABLED && event.keyCode == 8){event.stopPropagation();}return true;}

    $(document).ready(function(){ 
        if(BACKSPACE_NAV_DISABLED){
            //for IE use keydown, for Mozilla keypress  
            //as described in scr: http://www.codeproject.com/KB/scripting/PreventDropdownBackSpace.aspx
            $(document).keypress(fnPreventBackspace);
            $(document).keydown(fnPreventBackspace);

            //Allow Backspace is the following controls
            $('input').keypress(fnPreventBackspacePropagation);
            $('input').keydown(fnPreventBackspacePropagation);
            $('textarea').keypress(fnPreventBackspacePropagation);
            $('textarea').keydown(fnPreventBackspacePropagation);
        }
    }); 

</script>
like image 157
CodeNepal Avatar answered Oct 02 '22 16:10

CodeNepal