Question

I have a text box and a list box, my ultimate aim is to use the text box to filter the list box. The below code works however the text box is case sensitive and I need the user to be able to input any case and it filters the list box accordingly, at moment.

Example

"MY SITE" = Works
"my site" = Works
"My Site" = Does not work
"mY sITE" = Does not work 

my JQuery code is

var ddlText, ddlValue, ddl, lblMesg;

$(document).ready(function CacheItems() {
    ddlText = new Array(); ddlValue = new Array();
    ddl = document.getElementById("<%=lstSites.ClientID %>");
    for (var i = 0;
    i < ddl.options.length; i++) {
        ddlText[ddlText.length] = ddl.options[i].text;
        ddlValue[ddlValue.length] = ddl.options[i].value;
    }
});
window.onload = CacheItems;
function FilterItems(value) {
    ddl.options.length = 0; for (var i = 0; i < ddlText.length; i++) {
        if (ddlText[i].toLowerCase().indexOf(value) != -1) {
            AddItem(ddlText[i], ddlValue[i]);
        }
        else if (ddlText[i].toUpperCase().indexOf(value) != -1) {
            AddItem(ddlText[i], ddlValue[i]);
        }
    }
} 
function AddItem(text, value) {
    var opt = document.createElement("option");
    opt.text = text;
    opt.value = value;
    ddl.options.add(opt);
}

Thanks in advance for any help

Answer 1

You can extend jQuery with a new expression for this.

jQuery.extend(
    jQuery.expr[':'], { 
        ContainsInsensitive : "jQuery(a).text().toUpperCase().indexOf(m[3].toUpperCase())>=0" 
});

See contains() and Is there a case insensitive jQuery :contains selector?

…or simply transform both values to upper/lower case;

if (ddlText[i].toLowerCase().indexOf(value.toLowerCase()) != -1) {
  AddItem(ddlText[i], ddlValue[i]);
}