Adding comments to CodePush class

CodePush.h

@@ -1,7 +1,18 @@
 #import "RCTBridgeModule.h"
 
-@interface CodePush : NSObject<RCTBridgeModule>
+@interface CodePush : NSObject <RCTBridgeModule>
 
+/*
+ * This method is used to retreive the URL for the most recent
+ * version of the JavaScript bundle. This could be either the
+ * bundle that was packaged with the app binary, or the bundle
+ * that was downloaded as part of a CodePush update. The value returned
+ * should be used to "bootstrap" the React Native bridge.
+ *
+ * This method assumes that your JS bundle is named "main.jsbundle"
+ * and therefore, if it isn't, you should use either the bundleURLForResource:
+ * or bundleURLForResource:withExtension: methods to override thsat behavior.
+*/
 + (NSURL *)bundleURL;
 
 + (NSURL *)bundleURLForResource:(NSString *)resourceName;
@@ -25,7 +36,7 @@
 
 @end
 
-@interface CodePushDownloadHandler : NSObject<NSURLConnectionDelegate>
+@interface CodePushDownloadHandler : NSObject <NSURLConnectionDelegate>
 
 @property (strong) NSOutputStream *outputFileStream;
 @property long expectedContentLength;

CodePush.m

@@ -1,8 +1,9 @@
 #import "RCTBridgeModule.h"
-#import "RCTEventDispatcher.h"
 #import "RCTConvert.h"
+#import "RCTEventDispatcher.h"
 #import "RCTRootView.h"
 #import "RCTUtils.h"
+
 #import "CodePush.h"
 
 @implementation CodePush {
@@ -15,16 +16,17 @@ static BOOL didUpdate = NO;
 static NSTimer *_timer;
 static BOOL usingTestFolder = NO;
 
-static NSString * const FailedUpdatesKey = @"CODE_PUSH_FAILED_UPDATES";
-static NSString * const PendingUpdateKey = @"CODE_PUSH_PENDING_UPDATE";
+static NSString *const FailedUpdatesKey = @"CODE_PUSH_FAILED_UPDATES";
+static NSString *const PendingUpdateKey = @"CODE_PUSH_PENDING_UPDATE";
 
 // These keys are already "namespaced" by the PendingUpdateKey, so
 // their values don't need to be obfuscated to prevent collision with app data
-static NSString * const PendingUpdateHashKey = @"hash";
-static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
+static NSString *const PendingUpdateHashKey = @"hash";
+static NSString *const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
 
 @synthesize bridge = _bridge;
 
+// Public Obj-C API (see header for method comments)
 + (NSURL *)bundleURL
 {
     return [self bundleURLForResource:@"main"];
@@ -43,8 +45,7 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     NSString *packageFile = [CodePushPackage getCurrentPackageBundlePath:&error];
     NSURL *binaryJsBundleUrl = [[NSBundle mainBundle] URLForResource:resourceName withExtension:resourceExtension];
     
-    if (error || !packageFile)
-    {
+    if (error || !packageFile) {
         return binaryJsBundleUrl;
     }
     
@@ -61,14 +62,21 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     }
 }
 
-// Public Obj-C API
 + (NSString *)getDocumentsDirectory
 {
     NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
     return documentsDirectory;
 }
 
-// Internal API methods
+// Private API methods
+
+/*
+ * This method cancels the currently running rollback
+ * timer, which has the effect of stopping an automatic
+ * rollback from occuring. 
+ *
+ * Note: This method is safe to call from any thread.
+ */
 - (void)cancelRollbackTimer
 {
     dispatch_async(dispatch_get_main_queue(), ^{
@@ -76,6 +84,14 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     });
 }
 
+/* 
+ * This method checks to see whether a "pending udpate" has been applied
+ * (e.g. install was called with a non-immediate mode), but the app hasn't
+ * yet been restarted (either naturally or synthentically). If there is one,
+ * it will restart the app (if specified), and start the rollback timer.
+ *
+ * Note: This method is safe to call from any thread.
+ */
 - (void)checkForPendingUpdate:(BOOL)needsRestart
 {
     dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
@@ -93,15 +109,24 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
             if ([pendingHash isEqualToString:currentHash]) {
                 int rollbackTimeout = [pendingUpdate[PendingUpdateRollbackTimeoutKey] intValue];
                 [self initializeUpdateWithRollbackTimeout:rollbackTimeout needsRestart:needsRestart];
-                
-                // Clear the pending update and sync
-                [preferences removeObjectForKey:PendingUpdateKey];
-                [preferences synchronize];
+            } else {
+                // NOTE: We shouldn't ever reach here
             }
+                            
+            // Clear the pending update and sync
+            [preferences removeObjectForKey:PendingUpdateKey];
+            [preferences synchronize];
         }
     });
 }
 
+/*
+ * This method is meant as a handler for the global app
+ * resume notification, and therefore, should not be called
+ * directly. It simply checks to see whether there is a pending
+ * update that is meant to be installed on resume, and if so
+ * it applies it and restarts the app.
+ */
 - (void)checkForPendingUpdateDuringResume
 {
     // In order to ensure that CodePush doesn't impact the app's
@@ -112,6 +137,12 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     }
 }
 
+/*
+ * This method is used by the React Native bridge to allow
+ * our plugin to expose constants to the JS-side. In our case
+ * we're simply exporting enum values so that the JS and Native
+ * sides of the plugin can be in sync.
+ */
 - (NSDictionary *)constantsToExport
 {
     // Export the values of the CodePushInstallMode enum
@@ -151,6 +182,14 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     return self;
 }
 
+/*
+ * This method performs the actual initialization work for a update
+ * to ensure that the neccessary state is setup, including:
+ * --------------------------------------------------------
+ * 1. Updating the current bundle URL to point at the latest update on disk
+ * 2. Optionally restarting the app to load the new bundle
+ * 3. Optionally starting the rollback protection timer
+ */
 - (void)initializeUpdateWithRollbackTimeout:(int)rollbackTimeout
                                needsRestart:(BOOL)needsRestart
 {
@@ -167,6 +206,10 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     }
 }
 
+/*
+ * This method checks to see whether a specific package hash
+ * has previously failed installation.
+ */
 - (BOOL)isFailedHash:(NSString*)packageHash
 {
     NSUserDefaults *preferences = [NSUserDefaults standardUserDefaults];
@@ -174,6 +217,11 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     return (failedUpdates != nil && [failedUpdates containsObject:packageHash]);
 }
 
+/*
+ * This method updates the React Native bridge's bundle URL
+ * to point at the latest CodePush update, and then restarts
+ * the bridge. This isn't meant to be called directly.
+ */
 - (void)loadBundle
 {
     // If the current bundle URL is using http(s), then assume the dev
@@ -187,6 +235,13 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     [_bridge reload];
 }
 
+/*
+ * This method is used when an update has failed installation
+ * and the app needs to be rolled back to the previous bundle.
+ * This method is automatically called when the rollback timer
+ * expires without the app indicating whether the update succeeded,
+ * and therefore, it shouldn't be called directly.
+ */
 - (void)rollbackPackage
 {
     NSError *error;
@@ -201,6 +256,11 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     [self loadBundle];
 }
 
+/*
+ * When an update failed to apply, this method can be called
+ * to store its hash so that it can be ignored on future
+ * attempts to check the server for an update.
+ */
 - (void)saveFailedUpdate:(NSString *)packageHash
 {
     NSUserDefaults *preferences = [NSUserDefaults standardUserDefaults];
@@ -218,6 +278,11 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     [preferences synchronize];
 }
 
+/*
+ * When an update is installed whose mode isn't IMMEDIATE, this method
+ * can be called to store the pending update's metadata (e.g. rollbackTimeout)
+ * so that it can be used when the actual update application occurs at a later point.
+ */
 - (void)savePendingUpdate:(NSString *)packageHash
           rollbackTimeout:(int)rollbackTimeout
 {
@@ -232,6 +297,10 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
     [preferences synchronize];
 }
 
+/*
+ * This method handles starting the actual rollback timer
+ * after an update has been installed.
+ */
 - (void)startRollbackTimer:(int)rollbackTimeout
 {
     double timeoutInSeconds = rollbackTimeout / 1000;
@@ -243,42 +312,57 @@ static NSString * const PendingUpdateRollbackTimeoutKey = @"rollbackTimeout";
 }
 
 // JavaScript-exported module methods
+
+/*
+ * This is native-side of the RemotePackage.download method
+ */
 RCT_EXPORT_METHOD(downloadUpdate:(NSDictionary*)updatePackage
                         resolver:(RCTPromiseResolveBlock)resolve
                         rejecter:(RCTPromiseRejectBlock)reject)
 {
     [CodePushPackage downloadPackage:updatePackage
-                    progressCallback:^(long expectedContentLength, long receivedContentLength) {
-                        [self.bridge.eventDispatcher
-                         sendAppEventWithName:@"CodePushDownloadProgress"
-                         body:@{
-                                @"totalBytes":[NSNumber numberWithLong:expectedContentLength],
-                                @"receivedBytes":[NSNumber numberWithLong:receivedContentLength]
-                                }];
-                    }
-                        doneCallback:^{
-                            NSError *err;
-                            NSDictionary *newPackage = [CodePushPackage
-                                                        getPackage:updatePackage[@"packageHash"]
-                                                        error:&err];
-                            
-                            if (err) {
-                                return reject(err);
-                            }
-                            
-                            resolve(newPackage);
-                        }
-                        failCallback:^(NSError *err) {
-                            reject(err);
-                        }];
+        // The download is progressing forward
+        progressCallback:^(long expectedContentLength, long receivedContentLength) {
+            // Notify the script-side about the progress
+            [self.bridge.eventDispatcher
+                sendAppEventWithName:@"CodePushDownloadProgress"
+                body:@{
+                        @"totalBytes":[NSNumber numberWithLong:expectedContentLength],
+                        @"receivedBytes":[NSNumber numberWithLong:receivedContentLength]
+                      }];
+        }
+        // The download completed
+        doneCallback:^{
+            NSError *err;
+            NSDictionary *newPackage = [CodePushPackage getPackage:updatePackage[@"packageHash"] error:&err];
+                
+            if (err) {
+                return reject(err);
+            }
+                
+            resolve(newPackage);
+        }
+        // The download failed
+        failCallback:^(NSError *err) {
+            reject(err);
+        }];
 }
 
+/*
+ * This is the native side of the CodePush.getConfiguration method. It isn't
+ * currently exposed via the "react-native-code-push" module, and is used
+ * internally only by the CodePush.checkForUpdate method in order to get the
+ * app version, as well as the deployment key that was configured in the Info.plist file.
+ */
 RCT_EXPORT_METHOD(getConfiguration:(RCTPromiseResolveBlock)resolve
                           rejecter:(RCTPromiseRejectBlock)reject)
 {
     resolve([[CodePushConfig current] configuration]);
 }
 
+/*
+ * This method is the native side of the CodePush.getCurrentPackage method.
+ */
 RCT_EXPORT_METHOD(getCurrentPackage:(RCTPromiseResolveBlock)resolve
                            rejecter:(RCTPromiseRejectBlock)reject)
 {
@@ -293,6 +377,9 @@ RCT_EXPORT_METHOD(getCurrentPackage:(RCTPromiseResolveBlock)resolve
     });
 }
 
+/*
+ * This method is the native side of the LocalPackage.install method.
+ */
 RCT_EXPORT_METHOD(installUpdate:(NSDictionary*)updatePackage
                 rollbackTimeout:(int)rollbackTimeout
                     installMode:(CodePushInstallMode)installMode
@@ -318,6 +405,10 @@ RCT_EXPORT_METHOD(installUpdate:(NSDictionary*)updatePackage
     });
 }
 
+/*
+ * This method isn't publically exposed via the "react-native-code-push"
+ * module, and is only used internally to populate the RemotePackage.failedApply property.
+ */
 RCT_EXPORT_METHOD(isFailedUpdate:(NSString *)packageHash
                          resolve:(RCTPromiseResolveBlock)resolve
                           reject:(RCTPromiseRejectBlock)reject)
@@ -326,19 +417,26 @@ RCT_EXPORT_METHOD(isFailedUpdate:(NSString *)packageHash
     resolve(@(isFailedHash));
 }
 
+/*
+ * This method isn't publically exposed via the "react-native-code-push"
+ * module, and is only used internally to populate the LocalPackage.isFirstRun property.
+ */
 RCT_EXPORT_METHOD(isFirstRun:(NSString *)packageHash
                      resolve:(RCTPromiseResolveBlock)resolve
                     rejecter:(RCTPromiseRejectBlock)reject)
 {
     NSError *error;
     BOOL isFirstRun = didUpdate
-    && nil != packageHash
-    && [packageHash length] > 0
-    && [packageHash isEqualToString:[CodePushPackage getCurrentPackageHash:&error]];
+                        && nil != packageHash
+                        && [packageHash length] > 0
+                        && [packageHash isEqualToString:[CodePushPackage getCurrentPackageHash:&error]];
     
     resolve(@(isFirstRun));
 }
 
+/*
+ * This method is the native side of the CodePush.notifyApplicationReady() method.
+ */
 RCT_EXPORT_METHOD(notifyApplicationReady:(RCTPromiseResolveBlock)resolve
                                 rejecter:(RCTPromiseRejectBlock)reject)
 {
@@ -346,13 +444,18 @@ RCT_EXPORT_METHOD(notifyApplicationReady:(RCTPromiseResolveBlock)resolve
     resolve([NSNull null]);
 }
 
-// This function is exposed solely for immediately installed
-// update support, and shouldn't be consumed directly by user code.
+/*
+ * This method isn't publically exposed via the "react-native-code-push"
+ * module, and is only used internally to support immediately installed updates.
+ */
 RCT_EXPORT_METHOD(restartImmedidateUpdate:(int)rollbackTimeout)
 {
     [self initializeUpdateWithRollbackTimeout:rollbackTimeout needsRestart:YES];
 }
 
+/*
+ * This method is the native side of the CodePush.restartPendingUpdate() method.
+ */
 RCT_EXPORT_METHOD(restartPendingUpdate)
 {
     [self checkForPendingUpdate:YES];