better error handling. fallback widget

Signed-off-by: Benny Samir Hierl <bennysamir@posteo.de>

VodafoneDE/VodafoneDE.js

@@ -2,9 +2,21 @@
 // These must be at the very top of the file. Do not edit.
 // icon-color: teal; icon-glyph: magic;
 
-// Credits: 
-//   - Sillium@GitHub (https://gist.github.com/Sillium/f904fb89444bc8dde12cfc07b8fa8728)
-//   - Chaeimg@Github (https://github.com/chaeimg/battCircle)
+/**************
+Version 1.0.1
+
+Changelog:
+  v1.0.1:
+          - Better Error handling
+          - Better logging
+          - Fallback Widget screen in case of an error
+
+If you have problems or need help, ask for support here: https://github.com/ThisIsBenny/iOS-Widgets/issues
+
+Credits: 
+  - Sillium@GitHub (https://gist.github.com/Sillium/f904fb89444bc8dde12cfc07b8fa8728)
+  - Chaeimg@Github (https://github.com/chaeimg/battCircle)
+**************/
 
 // How many minutes should the cache be valid
 let cacheMinutes = 60;
@@ -101,12 +113,10 @@ async function getSessionCookies() {
   })
   try {
     let res = await req.loadJSON()
-    console.log("Login sucessfull")
     return { cookies: req.response.cookies, msisdn: res.msisdn}
   } catch (e) {
     console.log("Login vailed! Please check if Wifi is disabled.")
-    console.log(e)
-    throw e
+    throw new Error(`Login failed with HTTP-Status-Code ${req.response.statusCode}`)
   }
 };
 
@@ -130,15 +140,26 @@ async function getUsage() {
     let datenContainer = res['serviceUsageVBO']['usageAccounts'][0]['usageGroup'].find(function(v){
       return v.container == "Daten"
     })
+    
+    if (datenContainer === undefined) {
+      throw new Error("Can't find usageGroup 'Daten'")
+    } else {
       console.log("usageGroup 'Daten' founded")
+    }
+    
     let datenvolumen = datenContainer.usage.find(function(v){
       return v.code == "-1"
     })
-    console.log(datenvolumen)
+    
+    if (datenvolumen === undefined) {
+      console.log("Can't find Usage with Code -1. Please check the following log to find the correct code for your case and addjust the code to 4 lines above: " + JSON.stringify(datenContainer.usage))
+      throw new Error("Can't find Usage with Code -1.")
+    }
+    
     return {
-      total: datenvolumen.total || 0,
-      used: datenvolumen.used || 0,
-      remaining: datenvolumen.remaining || 0
+      total: datenvolumen.total,
+      used: datenvolumen.used,
+      remaining: datenvolumen.remaining
     }
   } catch (e) {
     console.log("Loading usage data failed")
@@ -181,18 +202,21 @@ try {
   }
 } catch (e) {
   console.log(e)
+  if (cacheExists) { 
     console.log("Get from Cache")
     data = JSON.parse(files.readString(cachePath))
     lastUpdate = cacheDate
+  } else {
+    console.log("No fallback to cache possible. Due to missing cache.")
+  }
 }
-
-console.log(data)
 
 // Create Widget
 let widget = new ListWidget();
 
 widget.setPadding(10, 10, 10, 10)
 
+if (data !== undefined) {
   if (useGradient) {
     const gradient = new LinearGradient()
     gradient.locations = [0, 1]
@@ -252,6 +276,11 @@ lastUpdateText.font = Font.mediumSystemFont(10)
   lastUpdateText.centerAlignText()
   lastUpdateText.applyTimeStyle()
   lastUpdateText.textColor = Color.lightGray() 
+} else {
+  let fallbackText = widget.addText("Es ist ein Fehler aufgetreten! Bitte prüfen Sie die Logs direkt in der App.")
+  fallbackText.font = Font.mediumSystemFont(12)
+  fallbackText.textColor = new Color(textColor)
+}
 
 if(!config.runsInWidget) {
   await widget.presentSmall()