WeatherInformation: conditions after AsyncTask

Before updating UI with data coming from AsyncTask through BroadcastReceiver we
must verify the data are the same as the ones that triggered the AsyncTask

I am trying to avoid this case:

1. Conditions trigger AsyncTask 1
2. Screen rotation (or any other thing that creates new instance of our Fragment)
3. Conditions trigger AsyncTask 2
4. AsyncTask 1 ends with success. Updates UI.
5. AsyncTask 2 ends with error. Show error message. <-------- PROBLEM!!!!

If before updating UI we check the current values, we may avoid the error created by AsyncTask 2.

diff --git a/src/de/example/exampletdd/fragment/current/CurrentFragment.java b/src/de/example/exampletdd/fragment/current/CurrentFragment.java
index 68444c2..9b829f8 100644 (file)
--- a/src/de/example/exampletdd/fragment/current/CurrentFragment.java
+++ b/src/de/example/exampletdd/fragment/current/CurrentFragment.java
@@ -92,26 +92,34 @@ public class CurrentFragment extends Fragment {
     public void onResume() {
         super.onResume();
 
-        
+
         this.mReceiver = new BroadcastReceiver() {
 
                        @Override
                        public void onReceive(final Context context, final Intent intent) {
                                final String action = intent.getAction();
                                if (action.equals("de.example.exampletdd.UPDATECURRENT")) {
-                                       final Current current = (Current) intent.getSerializableExtra("current");
+                                       final Current currentRemote = (Current) intent.getSerializableExtra("current");
 
-                                       if (current != null) {
-                                               CurrentFragment.this.updateUI(current);
+                                       if (currentRemote != null) {
 
+                                               // 1. Check conditions. They must be the same as the ones that triggered the AsyncTask.
+                                               final DatabaseQueries query = new DatabaseQueries(CurrentFragment.this.getActivity().getApplicationContext());
+                                   final WeatherLocation weatherLocation = query.queryDataBase();
                                    final WeatherInformationApplication application =
-                                               (WeatherInformationApplication) getActivity().getApplication();
-                                   application.setCurrent(current);
+                                               (WeatherInformationApplication) CurrentFragment.this.getActivity().getApplication();
+                                   final Current current = application.getCurrent();
+
+                                   if (current == null || !CurrentFragment.this.isDataFresh(weatherLocation.getLastCurrentUIUpdate())) {
+                                       // 2. Update UI.
+                                       CurrentFragment.this.updateUI(currentRemote);
+
+                                       // 3. Update Data.
+                                           application.setCurrent(currentRemote);
+                                           weatherLocation.setLastCurrentUIUpdate(new Date());
+                                           query.updateDataBase(weatherLocation);
+                                   }
 
-                                   final DatabaseQueries query = new DatabaseQueries(CurrentFragment.this.getActivity().getApplicationContext());
-                                   final WeatherLocation weatherLocation = query.queryDataBase();
-                                   weatherLocation.setLastCurrentUIUpdate(new Date());
-                                   query.updateDataBase(weatherLocation);
                                        } else {
                                                // Empty UI and show error message
                                                CurrentFragment.this.clearUI();

diff --git a/src/de/example/exampletdd/fragment/overview/OverviewFragment.java b/src/de/example/exampletdd/fragment/overview/OverviewFragment.java
index c5e5e53..907791d 100644 (file)
--- a/src/de/example/exampletdd/fragment/overview/OverviewFragment.java
+++ b/src/de/example/exampletdd/fragment/overview/OverviewFragment.java
@@ -92,22 +92,30 @@ public class OverviewFragment extends ListFragment {
                        public void onReceive(final Context context, final Intent intent) {
                                final String action = intent.getAction();
                                if (action.equals("de.example.exampletdd.UPDATEFORECAST")) {
-                                       final Forecast forecast = (Forecast) intent.getSerializableExtra("forecast");
+                                       final Forecast forecastRemote = (Forecast) intent.getSerializableExtra("forecast");
 
-                                       if (forecast != null) {
-                                               OverviewFragment.this.updateUI(forecast);
+                                       if (forecastRemote != null) {
 
-                                   final WeatherInformationApplication application =
-                                               (WeatherInformationApplication) getActivity().getApplication();
-                                   application.setForecast(forecast);
-
-                                   final DatabaseQueries query = new DatabaseQueries(OverviewFragment.this.getActivity().getApplicationContext());
+                                               // 1. Check conditions. They must be the same as the ones that triggered the AsyncTask.
+                                               final DatabaseQueries query = new DatabaseQueries(OverviewFragment.this.getActivity().getApplicationContext());
                                    final WeatherLocation weatherLocation = query.queryDataBase();
-                                   weatherLocation.setLastForecastUIUpdate(new Date());
-                                   query.updateDataBase(weatherLocation);
+                                               final WeatherInformationApplication application =
+                                               (WeatherInformationApplication) OverviewFragment.this.getActivity().getApplication();
+                                               final Forecast forecast = application.getForecast();
+
+                                       if (forecast == null || !OverviewFragment.this.isDataFresh(weatherLocation.getLastForecastUIUpdate())) {
+                                               // 2. Update UI.
+                                               OverviewFragment.this.updateUI(forecastRemote);
+
+                                               // 3. Update Data.
+                                                       application.setForecast(forecastRemote);
+                                           weatherLocation.setLastForecastUIUpdate(new Date());
+                                           query.updateDataBase(weatherLocation);
+
+                                           // 4. Show list.
+                                           OverviewFragment.this.setListShownNoAnimation(true);
+                                       }
 
-                                   // Show list.
-                                   OverviewFragment.this.setListShownNoAnimation(true);
                                        } else {
                                                // Empty list and show error message (see setEmptyText in onCreate)
                                                OverviewFragment.this.setListAdapter(null);