webix.protoUI({
name:"isodate",
$cssName: 'datepicker',
defaults:{
type:"text",
icon:"calendar",
placeholder:"yyyy-mm-dd",
pattern:{ mask:"####-##-##", allow:/[0-9]/g}
}, webix.ui.text);
pattern is attached to webix.ui.text through webix.extend, but i don’t know how to make use of it.