op-packages/luci-app-passwall/luasrc/view/passwall/node_config/header.htm

<%
local api = self.api
-%>
<script type="text/javascript">
	//<![CDATA[
	function waitForElement(selector, callback) {
		const el = document.querySelector(selector);
		if (el) return callback(el);
		const observer = new MutationObserver(() => {
			const el = document.querySelector(selector);
			if (el) {
				observer.disconnect();
				callback(el);
			}
		});
		observer.observe(document.body, { childList: true, subtree: true });
	}

	function getOption(opt) {
		var obj;
		var id = 'cbid.<%=api.appname%>.<%=self.section%>.' + opt;
		obj = document.getElementsByName(id)[0] || document.getElementById(id);
		if (obj) {
			var combobox = document.getElementById('cbi.combobox.' + id);
			if (combobox) {
				obj.combobox = combobox;
			}
			var div = document.getElementById(id);
			if (div && div.getElementsByTagName("li").length > 0) {
				obj = div;
			}
			return obj;
		} else {
			return null;
		}
	}
	
	function update_node(data) {
		XHR.get('<%=api.url("update_node")%>', {
			id: "<%=self.section%>",
			data: JSON.stringify(data)
		},
		function(x, data) {
			if (x && x.status == 200 && data.code == 1) {
				window.location.reload();
			}
			else {
				alert("<%:Error%>");
			}
		});
	}
	//]]>
</script>