date_picker
Github

	function date_picker() {
		return _class('html')->date_picker('input_name', '2015-02-02');
	}
	function date_picker($name, $cur_date = '') {
		js('jquery-ui');
		css('jquery-ui');

		jquery('$(".datepicker").datepicker({ dateFormat: "yy-mm-dd" });');
		css('//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.10.4/css/jquery.ui.datepicker.min.css');

		$extra['id'] = $extra['id'] ?: __FUNCTION__.'_'.++$this->_ids[__FUNCTION__];
// TODO: use input() unified control
		return '<input type="text" name="'.$name.'" class="datepicker" value="'.$cur_date.'" style="width:80px" readonly="true" id="'.$extra['id'].'" />';
	}