diff --git a/assets/js/common.ts b/assets/js/common.ts
index effcd65..4608fc0 100644
--- a/assets/js/common.ts
+++ b/assets/js/common.ts
@@ -29,10 +29,10 @@ export function config (api, polling): Config {
 export const pvapp = {
 	run(conf: Config) {
 		appdata.conf = conf
-		createApp(appdata).mount()
 		if (appdata.conf.pollurl && !appdata.conf.nopoll) {
 			appdata.poll()
 		}
+		createApp(appdata).mount()
 	}
 }
 
@@ -49,12 +49,13 @@ const appdata = {
 	Data
 }
 
-// components
-// (move to separate module(s))
+// Data component
+// (move to comp_data.ts)
 
 function Data(name, action, domain: string): object {
 	domain = domain || this.conf.domain
 	const comp = {
+		id: this.conf.itemid,
 		name: name, // -> class of incoming/outgoing message
 		action: action, // (default) action of outgoing message
 		domain: domain, // domain of incoming/outgoing message
@@ -68,10 +69,14 @@ function Data(name, action, domain: string): object {
 		exec		// default function to execute upon button click
 	}
 	this.components[name] = comp
+	if (comp.id) {
+		sendMsg(this.conf, [domain, 'query', name, comp.id], {})
+	}
 	return comp
 }
 
-// appdata and component method definitions
+// Data methods
+// (move to comp_data.ts)
 
 function mounted(name: string, meta: any) {
 	if (meta.defexpr) {
@@ -120,6 +125,8 @@ function exec(action: string) {
 	sendMsg(conf, [this.domain, action, this.name, data.id], data)
 }
 
+// App (appdata) methods
+
 function handle(msg) {
 	const data = JSON.parse(msg.payload)
 	const [ domain, action, class_, item ] = msg.path.split('/')
@@ -129,6 +136,8 @@ function handle(msg) {
 		return
 	}
 	if (comp) {
+		// TODO: use more generic comp.update(data)
+		// ... or even more generic comp.handle(msg)
 		Object.assign(comp.data, data)
 	}
 }
@@ -137,7 +146,8 @@ function poll() {
 	dopoll(this)
 }
 
-// helper functions for data manipulation
+// helper functions for data manipulation (used by Data component)
+// (move to comp_data.ts)
 
 function setQuery(obj) {
 	for (const key in obj.data) {