how to accept only alphabetical pressed keys ( for "autocomplete" purpose )

Question

Hi there ... am wondering ... how to only accept alphabetical pressed keys from the keyboard .. i am using the jQuery .keypress method ... now i wanna know how to filter the passed key ...

i am trying to build a simple autocomplete plugin for jQuery ...i know a about jQuery UI, but i want to do it myself ...

thanks in advance :)

Answer 1

In your callback, you can check the event's keyCode property. If you want to disallow the key being entered, simply return false. For example:

$('#element').keypress(function(e)
{
    if(e.which < 65 || e.which > 90) //65=a, 90=z
        return false;
});

Note that this won't really work very well. The user could still paste in other text, or use a mouse-based entry device, or any number of other things.

I've edited this based on Tim Down's comment and replaced keyCode with which, which is correct across keydown, keyup, and keypress events.

Answer 2

You can bind a function to the field that replaces anything that's not in the a-z range.

<input name="lorem" class="alphaonly" />

<script type="text/javascript">
$('.alphaonly').bind('keyup blur',function(){ 
    $(this).val( $(this).val().replace(/[^a-z]/g,'') );
});
</script>

Source: random Google result

Answer 3

The following will prevent any character typed outside of a-z and A-Z from registering.

$("#your_input_id").keypress(function(e) {
    if (!/[a-z]/i.test(String.fromCharCode(e.which))) {
        return false;
    }
});

This won't prevent pasted or dragged text appearing. The surest way to do that is the change event, which is only fired once the input has lost the focus:

$("#your_input_id").change(function(e) {
    this.value = this.value.replace(/[^a-z]+/gi, "");
});