Objective-C Swift The steps described on this page explain how to quickly create a simple iOS application that makes requests to the YouTube Data API. This sample shows how to retrieve data about the **GoogleDevelopers** YouTube channel. The code also includes comments that explain how to modify the query to retrieve data about the current user's YouTube channel. > [!NOTE] > **Note:** The application does not conform with Apple's [iOS Human Interface Guidelines](http://developer.apple.com/library/ios/#DOCUMENTATION/UserExperience/Conceptual/MobileHIG/Introduction/Introduction.html). It is intended only to illustrate the basic concepts and steps needed to begin working with the YouTube Data API. ## Prerequisites To run this quickstart, you'll need: - [Xcode](https://developer.apple.com/xcode/) 8.0 or greater. - [CocoaPods](http://cocoapods.org/) dependency manager. - Access to the internet and a web browser. - A Google account. ## Step 1: Turn on the YouTube Data API 1. Use [this wizard](https://console.developers.google.com/start/api?id=youtube) to create or select a project in the Google Developers Console and automatically turn on the API. Click **Continue** , then **Go to credentials**. 2. On the **Create credentials** page, click the **Cancel** button. 3. At the top of the page, select the **OAuth consent screen** tab. Select an **Email address** , enter a **Product name** if not already set, and click the **Save** button. 4. Select the **Credentials** tab, click the **Create credentials** button and select **OAuth client ID**. 5. Select the application type **iOS** , enter the name "YouTube Data API Quickstart", bundle ID `com.example.QuickstartApp`, and click the **Create** button. ## Step 2: Prepare the workspace > [!NOTE] > **Note:** All of the examples are based on the name `com.example.QuickstartApp`. If you named your app something other than that, like `com.example.QuickstartYTApp`, change the string `QuickstartApp` to match your app name. 1. Open Xcode and create a new project: 1. Click **File \> New \> Project** , select the **iOS \> Application \> Single View Application** template, and click **Next**. 2. Set the **Product Name** to "QuickstartApp", **Organization Identifier** to "com.example", and **Language** to **Objective-C** . Below the organization identifer, you should see a generated **Bundle Identifier** that matches the **iOS Bundle ID** (`com.example.QuickstartApp`) that you entered in [step 1.b](https://developers.google.com/youtube/data/quickstart/ios.md.txt#step-1-turn-on-the-youtube-data-api). 3. Click **Next**. 4. Select a destination directory for the project and click **Create**. 2. Close the project by clicking **File \> Close Project**. 3. Open a Terminal window and navigate to the directory that contains the `QuickstartApp.xcodeproj` file you just created. 4. Run the following commands to create the Podfile, install the library, and open the resulting XCode project: cat << EOF > Podfile && platform :ios, '8.0' target 'QuickstartApp' do pod 'GoogleAPIClientForREST/YouTube', '~> 1.2.1' pod 'Google/SignIn', '~> 3.0.3' end EOF pod install && open QuickstartApp.xcworkspace 5. In the XCode Project Navigator select the project node "QuickstartApp". Then click the menu item **File \> Add files to "QuickstartApp"**.  6. Locate the `GoogleService-Info.plist` file downloaded earlier and select it. Click the **Options** button.  7. Make the following selections in the options window and then click the **Add** button: 1. Check the **Copy items if needed** checkbox. 2. Check all targets listed in the **Add to targets** section.  8. With the project node still selected, select "QuickstartApp" in the **TARGETS** section as shown in the two images below: 1. Click the area shown in this screenshot:  2. Then select the proper target:  9. Select the **Info** tab, and expand the **URL Types** section. 10. Click the **+** button, and add a **URL scheme** for your reversed client ID. To find this value, open the `GoogleService-Info.plist` configuration file that you selected in step 2.f. Look for the **REVERSED_CLIENT_ID** key. Copy the value of that key, and paste it into the **URL Schemes** box on the configuration page. Leave the other fields blank. 11. Rebuild the project: 1. Click **Product \> Clean Build Folder** (while holding the **option** key). 2. Click **Product \> Build**. ## Step 3: Set up the sample Replace the contents of the following files with the code provided:
AppDelegate.h ``` #import @import GoogleSignIn; @interface AppDelegate : UIResponder @property (strong, nonatomic) UIWindow *window; @end ``` AppDelegate.m ``` #import "AppDelegate.h" @implementation AppDelegate - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Initialize Google sign-in. [GIDSignIn sharedInstance].clientID = @""; return YES; } - (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation { return [[GIDSignIn sharedInstance] handleURL:url sourceApplication:sourceApplication annotation:annotation]; } @end ``` ViewController.h ``` #import @import GoogleSignIn; #import @interface ViewController : UIViewController @property (nonatomic, strong) IBOutlet GIDSignInButton *signInButton; @property (nonatomic, strong) UITextView *output; @property (nonatomic, strong) GTLRYouTubeService *service; @end ``` ViewController.m ``` #import "ViewController.h" @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Configure Google Sign-in. GIDSignIn* signIn = [GIDSignIn sharedInstance]; signIn.delegate = self; signIn.uiDelegate = self; signIn.scopes = [NSArray arrayWithObjects:kGTLRAuthScopeYouTubeReadonly, nil]; [signIn signInSilently]; // Add the sign-in button. self.signInButton = [[GIDSignInButton alloc] init]; [self.view addSubview:self.signInButton]; // Create a UITextView to display output. self.output = [[UITextView alloc] initWithFrame:self.view.bounds]; self.output.editable = false; self.output.contentInset = UIEdgeInsetsMake(20.0, 0.0, 20.0, 0.0); self.output.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth; self.output.hidden = true; [self.view addSubview:self.output]; // Initialize the service object. self.service = [[GTLRYouTubeService alloc] init]; } - (void)signIn:(GIDSignIn *)signIn didSignInForUser:(GIDGoogleUser *)user withError:(NSError *)error { if (error != nil) { [self showAlert:@"Authentication Error" message:error.localizedDescription]; self.service.authorizer = nil; } else { self.signInButton.hidden = true; self.output.hidden = false; self.service.authorizer = user.authentication.fetcherAuthorizer; [self fetchChannelResource]; } } // Construct a query and retrieve the channel resource for the GoogleDevelopers // YouTube channel. Display the channel title, description, and view count. - (void)fetchChannelResource { GTLRYouTubeQuery_ChannelsList *query = [GTLRYouTubeQuery_ChannelsList queryWithPart:@"snippet,statistics"]; query.identifier = @"UC_x5XG1OV2P6uZZ5FSM9Ttw"; // To retrieve data for the current user's channel, comment out the previous // line (query.identifier ...) and uncomment the next line (query.mine ...). // query.mine = true; [self.service executeQuery:query delegate:self didFinishSelector:@selector(displayResultWithTicket:finishedWithObject:error:)]; } // Process the response and display output - (void)displayResultWithTicket:(GTLRServiceTicket *)ticket finishedWithObject:(GTLRYouTube_ChannelListResponse *)channels error:(NSError *)error { if (error == nil) { NSMutableString *output = [[NSMutableString alloc] init]; if (channels.items.count > 0) { [output appendString:@"Channel information:\n"]; for (GTLRYouTube_Channel *channel in channels) { NSString *title = channel.snippet.title; NSString *description = channel.snippet.description; NSNumber *viewCount = channel.statistics.viewCount; [output appendFormat:@"Title: %@\nDescription: %@\nViewCount: %@\n", title, description, viewCount]; } } else { [output appendString:@"Channel not found."]; } self.output.text = output; } else { [self showAlert:@"Error" message:error.localizedDescription]; } } // Helper for showing an alert - (void)showAlert:(NSString *)title message:(NSString *)message { UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert]; UIAlertAction *ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) { [alert dismissViewControllerAnimated:YES completion:nil]; }]; [alert addAction:ok]; [self presentViewController:alert animated:YES completion:nil]; } @end ``` ## Step 4: Run the sample Switch to the **QuickstartApp** scheme by clicking **Product \> Scheme \> QuickstartApp** and run the sample (Cmd+R) using the device simulator or a configured device. The first time you run the sample, it will prompt you to log in to your Google account and authorize access. It worked! > [!TIP] > **Great!** Check out the further reading section below to learn more. I got an error > [!WARNING] > **Bummer.** Thanks for letting us know and we'll work to fix this quickstart. ## Notes - Authorization information is stored in your Keychain, so subsequent executions will not prompt for authorization. ## Further reading - [Google Developers Console help documentation](https://developers.google.com/console/help/new) - [Google APIs Client for iOS documentation](https://github.com/google/google-api-objectivec-client/wiki) - [YouTube Data API reference documentation](https://developers.google.com/youtube/data/reference/rest.md.txt)