luci-app-dawn: error message when service not running

Display a nicer error message when the DAWN service is not running

Signed-off-by: Daniel Vijge <danielvijge@gmail.com>

applications/luci-app-dawn/htdocs/luci-static/resources/dawn/dawn-common.js

@@ -7,13 +7,13 @@ let callDawnGetNetwork, callDawnGetHearingMap, callHostHints;
 callDawnGetNetwork = rpc.declare({
 	object: 'dawn',
 	method: 'get_network',
-	expect: {  }
+	expect: { }
 });
 
 callDawnGetHearingMap = rpc.declare({
 	object: 'dawn',
 	method: 'get_hearing_map',
-	expect: {  }
+	expect: { }
 });
 
 callHostHints = rpc.declare({
@@ -22,6 +22,12 @@ callHostHints = rpc.declare({
 	expect: { }
 });
 
+function isDawnRPCAvailable() {
+    return rpc.list("dawn").then(function(signatures) {
+        return 'dawn' in signatures && 'get_network' in signatures.dawn && 'get_hearing_map' in signatures.dawn;
+    });
+}
+
 function getAvailableText(available) {
 	return ( available ? _('Available') : _('Not available') );
 }
@@ -59,16 +65,26 @@ function getFormattedNumber(num, decimals, divider = 1) {
 }
 
 function getHostnameFromMAC(hosthints, mac) {
-	return ( hosthints[mac] && hosthints[mac].name ? hosthints[mac].name + ' (' + mac + ')' : mac);
+	return ( hosthints[mac] && hosthints[mac].name ? hosthints[mac].name + ' (' + mac + ')' : mac );
+}
+
+function getDawnServiceNotRunningErrorMessage() {
+	return E('div', { 'class': 'alert-message fade-in warning' }, [
+		E('h4', _('DAWN service unavailable')),
+		E('p', _('Unable to query the DAWN service via ubus, the service appears to be stopped.')),
+		E('a', { 'href': L.url('admin/system/startup') }, _('Check Startup services'))
+	]);
 }
 
 return L.Class.extend({
 	callDawnGetNetwork: callDawnGetNetwork, 
 	callDawnGetHearingMap: callDawnGetHearingMap,
 	callHostHints: callHostHints,
+	isDawnRPCAvailable: isDawnRPCAvailable,
 	getAvailableText: getAvailableText,
 	getYesText: getYesText,
 	getChannelFromFrequency: getChannelFromFrequency,
 	getFormattedNumber: getFormattedNumber,
-	getHostnameFromMAC: getHostnameFromMAC
+	getHostnameFromMAC: getHostnameFromMAC,
+	getDawnServiceNotRunningErrorMessage: getDawnServiceNotRunningErrorMessage
 });

applications/luci-app-dawn/htdocs/luci-static/resources/view/dawn/hearing_map.js

@@ -10,8 +10,12 @@ return view.extend({
 
 	load: function() {
 		return Promise.all([
-			dawn.callDawnGetHearingMap(),
+			dawn.isDawnRPCAvailable().then(function(isAvailable) {
-			dawn.callDawnGetNetwork(),
+				return ( isAvailable ? dawn.callDawnGetHearingMap() : null )
+			}),
+			dawn.isDawnRPCAvailable().then(function(isAvailable) {
+				return ( isAvailable ? dawn.callDawnGetNetwork() : null )
+			}),
 			dawn.callHostHints()
 		]);
 	},
@@ -37,6 +41,10 @@ return view.extend({
 			});
 		}
 
+		if (!dawnHearingMapData || !dawnNetworkData) {
+			return dawn.getDawnServiceNotRunningErrorMessage();
+		}
+
 		const body = E([
 			E('h2', _('Hearing Map'))
 		]);

applications/luci-app-dawn/htdocs/luci-static/resources/view/dawn/network_overview.js

@@ -10,7 +10,9 @@ return view.extend({
 
 	load: function() {
 		return Promise.all([
-			dawn.callDawnGetNetwork(),
+			dawn.isDawnRPCAvailable().then(function(isAvailable) {
+				return ( isAvailable ? dawn.callDawnGetNetwork() : null );
+			}),
 			dawn.callHostHints()
 		]);
 	},
@@ -20,6 +22,10 @@ return view.extend({
 		const dawnNetworkData = data[0];
 		const hostHintsData = data[1];
 
+		if (!dawnNetworkData) {
+			return dawn.getDawnServiceNotRunningErrorMessage();
+		}
+
 		const body = E([
 			E('h2', _('Network Overview'))
 		]);