Ian Hickson wrote:
On Sat, 11 Feb 2006, Sean Hogan wrote:
I would request a input filter as a regex range eg a-zA-Z0-9 i.e. if
the keyCode is NOT within the range then preventDefault(). I imagine
that number, date, datetime, etc will be special implementations that
filter keyboard input. Why not extend the facility to text, etc?
This is already possible using the pattern="" attribute:
http://whatwg.org/specs/web-forms/current-work/#pattern
Thanks,
I expressed myself poorly.
If I'm reading the spec correctly then "pattern" is used to
prevent/allow form submission, and to highlight an invalid entry.
What I am suggesting is a filter that can be matched against for each
keypress event.
If keyCode matches then the character is appended to the input as normal.
If it doesn't then the character is dropped on the floor.
Here is some code which may be correct for current W3C browsers.
The intention here is to only accept alphanumeric characters.
<input type="text" filter="a-zA-Z0-9" onkeypress="inputfilter" />
<script>
inputfilter(e) {
var n = e.keyCode || e.which; // keyCode is 0 for mozilla. use
which.
if (n==8 || n==9 || n==16 || n==17 || n==37 || n==39 || n==46)
return true; // don't filter control characters
var str = String.fromCharCode(n);
var filter = this.getAttribute("filter");
var r = new RegExp("["+filter+"]");
if (r.test(str)) return true;
e.preventDefault();
return false;
}
</script>
On second thoughts, it probably isn't a good idea to put this in the
standard.
It is probably within the same realm as spell checking and
auto-correction.
cheers,
SDH
