handle rpc exceptions

cyberwow/lib/controller/rpc.dart

@@ -30,9 +30,11 @@ Future<http.Response> rpc(String method) async {
   if (kReleaseMode) {
     url = 'http://127.0.0.1:34568/json_rpc';
   } else {
-    url = 'http://192.168.10.100:34568/json_rpc';
+    url = 'http://192.168.10.101:34568/json_rpc';
   }
 
+  url = 'http://127.0.0.1:34568/json_rpc';
+
   final body = json.encode
   (
     {
@@ -42,10 +44,16 @@ Future<http.Response> rpc(String method) async {
     }
   );
 
-  var response = await http.post
+  var response;
-  ( url,
+  try {
-    body: body
+    response = await http.post
-  );
+    ( url,
+      body: body
+    );
+  }
+  catch (e) {
+    print(e);
+  }
 
   return response;
 }
@@ -57,6 +65,8 @@ Future<http.Response> syncInfo() async {
 Future<int> targetHeight() async {
   var response = await syncInfo();
 
+  if (response == null) return -1;
+
   // print('Response status: ${response.statusCode}');
   if (response.statusCode != 200) {
     return -1;
@@ -69,6 +79,8 @@ Future<int> targetHeight() async {
 Future<int> height() async {
   var response = await syncInfo();
 
+  if (response == null) return -1;
+
   // print('Response status: ${response.statusCode}');
   if (response.statusCode != 200) {
     return -1;

cyberwow/lib/state.dart

@@ -171,7 +171,7 @@ class SyncedState extends HookedState {
 
     while (true) {
       final _targetHeight = await rpc.targetHeight();
-      if (_targetHeight != 0) break;
+      if (_targetHeight > 0) break;
       height = await rpc.height();
 
       await Future.delayed(const Duration(seconds: 2), () => "1");