Question

The code that I am using below works fine, except for the fact that it adds an ‘s’ if the cursor is left in an input field. How do I do a CTRL–S without having that pesky s being added?

window.onload = function() {

//-------------------------------------------------------------------->>
// CTRL-S FEATURE:
//-------------------------------------------------------------------->>
var isCtrl = false; 
document.attachEvent('onkeyup', KeyUpHandler); 
document.attachEvent('onkeydown', KeyDownHandler); 

function KeyUpHandler() {
    if (event.keyCode == 17) { 
    isCtrl = false; 
    }
}//end of function 

function KeyDownHandler() {
    if (event.keyCode == 17) { isCtrl = true }
    if (event.keyCode == 83 && isCtrl == true) {
    v8_update()
    } 
}//end of function

}//end of onload()

Much thanks and appreciation for all your help and support in advance,

Cheers

Jay

Answer 1

The keydown handler should prevent the default action from continuing — i.e. the character being inserted into the focused element. To accomplish this, use the preventDefault method of the event object:

function KeyDownHandler(evnt) {
    var evnt = evnt || window.event;
    if (evnt.keyCode == 83 && evnt.ctrlKey) {
        evnt.preventDefault ? evnt.preventDefault() : window.event.returnValue = false;
        v8_update();
        return false;
    }
}

On can also return false to stop propagation AND prevent default, however, this may be detrimental to other events that are bound to the same element as your event — you may desire propagation, especially when attaching such an event to the document itself. If so, take out the false return.

Try it here: http://jsfiddle.net/LzezS/

Documentation

• event.preventDefault on MDN – https://developer.mozilla.org/en/DOM:event.preventDefault
• DOM event specification on W3 – http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-Event-preventDefault
• MSDN and IE’s non-standard event model – http://msdn.microsoft.com/en-us/library/ie/ms534372%28v=vs.85%29.aspx
• event.ctrlKey on MDN – https://developer.mozilla.org/en/DOM/event.ctrlKey