Get Character value from KeyCode in Javascript...then trim.

Question

This is what i have now:

$("input").bind("keydown",function(e){

    var value = this.value + String.fromCharCode(e.keyCode);
}

If the e.keyCode may not be an ASCII character (alt, backspace, del, arrows, etc)... I would now need to "trim" these values from "value" somehow (preferably programmatically - not with lookup tables)

I'm using jQuery.
I must use the "keydown" event. "keyPress" doesn't activate for certain keys I need to capture (esc, del, backspace, etc...). I cannot use setTimeout to get the input's value. (setTimeout(function(){},0) is too slow.)

I'm stuck. Please help.

Answer 1

I'm assuming this is for a game or for a fast-responding type of application hence the use of KEYDOWN than KEYPRESS.

Edit: Dang! I stand corrected (thank you Crescent Fresh and David): JQuery (or even rather the underlying DOM hosts) do not expose the detail of the WM_KEYDOWN and of other events. Rather they pre-digest this data and, in the case of keyDown even in JQuery, we get:

• event.keyCode for non-character keys
• event.charCode for character keys

Note that these properties are the UniCode values.
Note, I wasn't able to find an authorititative reference to that in JQuery docs, but many reputable examples on the net refer to these two properties.

The following code, adapted from some java (not javascript) of mine, is therefore totally wrong...

The following will give you the "interesting" parts of the keycode:

  value = e.KeyCode;
  repeatCount = value & 0xFF;
  scanCode = (value >> 16) & 0xFF;  // note we take the "extended bit" deal w/ it later.
  wasDown = ((value & 0x4000) != 0);  // indicate key was readily down (auto-repeat)
  if (scanCode > 127)
      // deal with extended
  else
      // "regular" character

Answer 2

Maybe I didn't understand the question correctly, but can you not use keyup of you want to capture both?

$("input").bind("keyup",function(e){
    var value = this.value + String.fromCharCode(e.keyCode);
}