Having the same issue here. Looks like it is not considered when the HTML input (type=text) is rendered and so no property is available for that.
One but not an elegant solution is to validation the rendered HTML input. I believe it is named with "_input" appended to the <WebComboClientID or Name> so something like WebCombo1_input. or maybe modify it's attribute at page load but as I've said not really elegant so hopefully Infragistics could shed light on this.
Hello Varlynstroud
You can use the property EditKeyDown of ClientSideEvents and use the javascript code below.
<div>
<igcmbo:WebCombo ID="WebCombo1" runat="server" Editable="true">
</igcmbo:WebCombo>
</div>
</form>
<script type="text/javascript">
function Validation(comboId, comboString, button){
if(comboString.toString().length > 5){
return true;
}
return false;
</script>
Hope this helps.