Can you restrict entering invalid keystrokes with jQuery UI autocomplete combobox?

Question

When using the jQuery UI autocomplete combobox, I would thought there would be an option to force only a valid key entry based on the list. Is there any way to not allow invalid keys, so you can only enter valid items in the list? Also, is there a way to set a default value of the combobox?

If my list has (C#, Java, Python)

I can start typing "abcds . ." and it lets me type it in. I want only valid entries to be allowed.

Answer 1

UPDATED 2

Tested on
Internet Explorer 6 and later
Chrome
Firefox
Opera

Demo: http://so.lucafilosofi.com/can-you-restrict-entering-invalid-keystrokes-with-jquery-ui-autocomplete-combobox

Core JavaScript code:

    var Tags = ['csharp', 'java', 'python' ];

    $("#autocomplete").keypress(function(event) {
        //Firefox workaround..
        if (!event.which &&
            ((event.charCode || event.charCode === 0) ? event.charCode: event.keyCode)) {

            event.which = event.charCode || event.keyCode;
        }
        var charCode = String.fromCharCode(event.which).toLowerCase();
        var search_val = this.value + charCode;
        var x = search_val.length - 1;
        var match;
        for (var i = 0; i < Tags.length; i++) {
            if (charCode == Tags[i][x] && Tags[i].indexOf(search_val) != -1) {
                match = true;
            }
        }
        //Backspace functionality added!
        if (!match && event.which != 8 ) {
            event.preventDefault();
        }
    });

NOTE:

1. force only valid key entry based on the list;
2. set a default value;
3. lightweight implementation ;-)

Let me know!