Merge pull request #275 from Microsoft/reload

Android reload refactor

Author: lostintangent

android/app/src/main/java/com/microsoft/codepush/react/CodePush.java

@@ -1,5 +1,6 @@
 package com.microsoft.codepush.react;
 
+import com.facebook.react.ReactActivity;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.bridge.JavaScriptModule;
 import com.facebook.react.bridge.LifecycleEventListener;
@@ -29,6 +30,10 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import java.lang.ReflectiveOperationException;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -101,7 +106,6 @@ public CodePush(String deploymentKey, Activity mainActivity, boolean isDebugMode
             throw new CodePushUnknownException("Unable to get package info for " + applicationContext.getPackageName(), e);
         }
 
-        initializeUpdateAfterRestart();
         if (currentInstance != null) {
             CodePushUtils.log("More than one CodePush instance has been initialized. Please use the instance method codePush.getBundleUrlInternal() to get the correct bundleURL for a particular instance.");
         }
@@ -147,7 +151,7 @@ public static String getBundleUrl(String assetsBundleFileName) {
 
         return currentInstance.getBundleUrlInternal(assetsBundleFileName);
     }
-
+    
     public String getBundleUrlInternal(String assetsBundleFileName) {
         this.assetsBundleFileName = assetsBundleFileName;
         String binaryJsBundleUrl = ASSETS_BUNDLE_PREFIX + assetsBundleFileName;
@@ -356,13 +360,74 @@ public void clearUpdates() {
     private class CodePushNativeModule extends ReactContextBaseJavaModule {
         private LifecycleEventListener lifecycleEventListener = null;
         private int minimumBackgroundDuration = 0;
+        
+        public CodePushNativeModule(ReactApplicationContext reactContext) {
+            super(reactContext);
+        }
+        
+        @Override
+        public Map<String, Object> getConstants() {
+            final Map<String, Object> constants = new HashMap<>();
+            constants.put("codePushInstallModeImmediate", CodePushInstallMode.IMMEDIATE.getValue());
+            constants.put("codePushInstallModeOnNextRestart", CodePushInstallMode.ON_NEXT_RESTART.getValue());
+            constants.put("codePushInstallModeOnNextResume", CodePushInstallMode.ON_NEXT_RESUME.getValue());
+            return constants;
+        }
 
-        private void loadBundle() {
+        @Override
+        public String getName() {
+            return "CodePush";
+        }
+        
+        @Override
+        public void initialize() {
+            CodePush.this.initializeUpdateAfterRestart();
+        }
+    
+        private void loadBundleLegacy() {
             Intent intent = mainActivity.getIntent();
             mainActivity.finish();
             mainActivity.startActivity(intent);
+            
             currentInstance = null;
         }
+        
+        private void loadBundle() {
+            try {
+                // #1) Get the private ReactInstanceManager, which is what includes
+                //     the logic to reload the current React context.
+                Field instanceManagerField = ReactActivity.class.getDeclaredField("mReactInstanceManager");
+                instanceManagerField.setAccessible(true); // Make a private field accessible
+                final Object instanceManager = instanceManagerField.get(mainActivity);
+
+                // #2) Update the locally stored JS bundle file path
+                String latestJSBundleFile = CodePush.this.getBundleUrlInternal(CodePush.this.assetsBundleFileName);
+                Field jsBundleField = instanceManager.getClass().getDeclaredField("mJSBundleFile");
+                jsBundleField.setAccessible(true);
+                jsBundleField.set(instanceManager, latestJSBundleFile);
+                            
+                // #3) Get the context creation method and fire it on the UI thread (which RN enforces)
+                final Method recreateMethod = instanceManager.getClass().getMethod("recreateReactContextInBackground");
+                mainActivity.runOnUiThread(new Runnable() {
+                    @Override
+                    public void run() {
+                        try {
+                            recreateMethod.invoke(instanceManager);
+                        }
+                        catch (ReflectiveOperationException e) {
+                            // The recreation method threw an unknown exception
+                            // so just simply fallback to restarting the Activity
+                            loadBundleLegacy();
+                        }
+                    }
+                });
+            }
+            catch (ReflectiveOperationException e) {
+                // Our reflection logic failed somewhere
+                // so fall back to restarting the Activity
+                loadBundleLegacy();
+            }
+        }
 
         @ReactMethod
         public void downloadUpdate(final ReadableMap updatePackage, final Promise promise) {
@@ -597,24 +662,6 @@ public void downloadAndReplaceCurrentBundle(String remoteBundleUrl) {
                 }
             }
         }
-
-        @Override
-        public Map<String, Object> getConstants() {
-            final Map<String, Object> constants = new HashMap<>();
-            constants.put("codePushInstallModeImmediate", CodePushInstallMode.IMMEDIATE.getValue());
-            constants.put("codePushInstallModeOnNextRestart", CodePushInstallMode.ON_NEXT_RESTART.getValue());
-            constants.put("codePushInstallModeOnNextResume", CodePushInstallMode.ON_NEXT_RESUME.getValue());
-            return constants;
-        }
-
-        public CodePushNativeModule(ReactApplicationContext reactContext) {
-            super(reactContext);
-        }
-
-        @Override
-        public String getName() {
-            return "CodePush";
-        }
     }
 
     @Override
@@ -638,4 +685,4 @@ public List<Class<? extends JavaScriptModule>> createJSModules() {
     public List<ViewManager> createViewManagers(ReactApplicationContext reactApplicationContext) {
         return new ArrayList<>();
     }
-}
+}