App Center Distribute – iOS In-app updates

Important

Visual Studio App Center is scheduled for retirement on March 31, 2025. While you can continue to use Visual Studio App Center until it is fully retired, there are several recommended alternatives that you may consider migrating to.

Learn more about support timelines and alternatives.

App Center Distribute will let your users install a new version of the app when you distribute it via App Center. With a new version of the app available, the SDK will present an update dialog to the users to either download or postpone the new version. Once they choose to update, the SDK will start to update your application.

Note

There are a few things to consider when using in-app updates:

1. If you've released your app in the App Store, in-app updates will be disabled.
2. If you're running automated UI tests, enabled in-app updates will block your automated UI tests as they'll try to authenticate against the App Center backend. We recommend to not enable App Center Distribute for your UI test target.

Note

In the 4.0.0 version of App Center breaking changes were introduced. Follow the Migrate to App Center SDK 4.0.0 and higher section to migrate App Center from previous versions.

Important

App Center SDK doesn't support multiple window apps that were introduced in iOS 13.

Add in-app updates to your app

Follow the Get started section if you haven't configured the SDK in your application.

1. Add the App Center Distribute module

The App Center SDK is designed with a modular approach – you only need to integrate the modules of the services that you're interested in.

Integration via Cocoapods

If you're integrating App Center into your app via Cocoapods, add the following dependency to your podfile and run pod install.

Ruby

pod 'AppCenter/Distribute'

Integration via Carthage

1. Add the following dependency to your Cartfile to include App Center Distribute.

   Ruby

   # Use the following line to get the latest version of App Center
   github "microsoft/appcenter-sdk-apple"
   

   Ruby

   # Use the following line to get the specific version of App Center
   github "microsoft/appcenter-sdk-apple" ~> X.X.X
   

2. Run carthage update.

3. Open your application target's General settings tab. Drag and drop the AppCenterDistribute.framework file from the Carthage/Build/iOS folder to the Linked Frameworks and Libraries section in XCode.

4. Drag and drop AppCenterDistributeResources.bundle from AppCenterDistribute.framework into XCode's Project Navigator.

5. A dialog will appear, make sure your app target is checked. Then click Finish.

Integration via Swift Package Manager

1. From the Xcode menu click File > Swift Packages > Add Package Dependency.
2. In the dialog that appears, enter the repository URL: https://github.com/microsoft/appcenter-sdk-apple.git.
3. In Version, select Up to Next Major and take the default option.
4. Choose the AppCenterDistribute in the Package Product column.

Integration by copying the binaries into your project

If you don't want to use Cocoapods, you can integrate the modules by copying the binaries into your project. Follow the steps below:

Note

App Center SDK supports the use of XCframework. If you want to integrate XCframeworks into your project, download the AppCenter-SDK-Apple-XCFramework.zip from the releases page and unzip it. Resulting folder contents aren't platform-specific, instead it contains XCframeworks for each module. They can be integrated the same way as usual frameworks, as described below.

1. Download the App Center SDK frameworks provided as a zip file.

2. Unzip the file and you'll see a folder called AppCenter-SDK-Apple/iOS that contains different frameworks for each App Center service. The framework called AppCenter is required in the project as it contains code that's shared between the different modules.

3. [Optional] Create a subdirectory for 3rd-party libraries.

   • As a best practice, 3rd-party libraries are usually inside a subdirectory, often called Vendor. If your project isn't organized with a subdirectory for libraries, create a Vendor subdirectory now.
   • Create a group called Vendor inside your Xcode project to mimic the file structure on disk.

4. Open Finder and copy the unzipped AppCenter-SDK-Apple/iOS folder into your project's folder at the location where you want it.

5. Add the SDK framework to the project in Xcode:

   • Make sure the Project Navigator is visible (⌘+1).
   • Now drag and drop AppCenter.framework, AppCenterDistribute.framework, and AppCenterDistributeResources.bundle from the Finder (the ones inside the Vendor folder) into Xcode's Project Navigator. AppCenter.framework is required to start the SDK. Make sure it's added to your project, otherwise the other modules won't work, and your project won't compile successfully.
   • A dialog will appear, make sure your app target is checked. Then click Finish.

2. Start App Center Distribute

App Center only uses the specific modules you invoke in your application. You must explicitly call each of them when starting the SDK.

2.1 Add the import for App Center Distribute

Open the project's AppDelegate.m file in Objective-C or AppDelegate.swift file in Swift and add the following import statements:

Swift

import AppCenter
import AppCenterDistribute

2.2 Add the start:withServices: method

Add Distribute to your start:withServices: method to start App Center Distribute service.

Insert the following line to start the SDK in the project's AppDelegate.m class for Objective-C or AppDelegate.swift class for Swift in the didFinishLaunchingWithOptions method.

Swift

AppCenter.start(withAppSecret: "{Your App Secret}", services: [Distribute.self])

Make sure you've replaced {Your App Secret} in the code sample above with your App Secret. Also check out the Get started section if you haven't configured the SDK in your application.

2.3 Modify the project's Info.plist

1. In the project's Info.plist file, add a new key for URL types by clicking the '+' button next to "Information Property List" at the top. If Xcode displays your Info.plist as source code, refer to the tip below.
2. Change the key type to Array.
3. Add a new entry to the array (Item 0) and change the type to Dictionary.
4. Under Item 0, add a URL Schemes key and change the type to Array.
5. Under your URL Schemes key, add a new entry (Item 0).
6. Under URL Schemes > Item 0, change the value to appcenter-{APP_SECRET} and replace {APP_SECRET} with the App Secret of your app.

Tip

If you want to verify that you modified the Info.plist correctly, open it as source code. It should contain the following entry with your App Secret instead of {APP_SECRET}:

XML

<key>CFBundleURLTypes</key>
<array>
  <dict>
  	<key>CFBundleURLSchemes</key>
  	<array>
  		<string>appcenter-{APP_SECRET}</string>
  	</array>
  </dict>
</array>

Use private distribution group

By default, Distribute uses a public distribution group. If you want to use a private distribution group, you'll need to explicitly set it via updateTrack property.

Swift

Distribute.updateTrack = .private

Note

The default value is UpdateTrack.public. This property can only be updated before the AppCenter.start method call. Changes to the update track aren't persisted when the application process restarts, thus if the property isn't always updated before the AppCenter.start call, it will be public, by default.

After this call, a browser window will open up to authenticate the user. All the subsequent update checks will get the latest release on the private track.

If a user is on the private track, it means that after the successful authentication, they'll get the latest release from any private distribution groups they're a member of. If a user is on the public track, it means that they'll get the latest release from any public distribution group.

Disable Automatic Check for Update

By default, the SDK automatically checks for new releases:

• When the application starts.
• When the application goes into background then in foreground again.
• When enabling the Distribute module if previously disabled.

If you want to check for new releases manually, you can disable automatic check for update. To do this, call the following method before the SDK start:

Swift

Distribute.disableAutomaticCheckForUpdate()

Note

This method must be called before the AppCenter.start method call.

Then you can use the checkForUpdate API which is described in the following section.

Manually Check for Update

Swift

Distribute.checkForUpdate()

This sends a request to App Center and display an update dialog in case there's a new release available.

Note

A manual check for update call works even when automatic updates are enabled. A manual check for update is ignored if another check is already being done. The manual check for update won't be processed if the user has postponed updates (unless the latest version is a mandatory update).

Customize or localize the in-app update dialog

1. Customize or localize text

You can easily provide your own resource strings if you want to localize the text displayed in the update dialog. Look at this strings file. Use the same string name/key and specify the localized value to be reflected in the dialog in your own app strings files.

2. Customize the update dialog

You can customize the default update dialog's appearance by implementing the DistributeDelegate protocol. You need to register the delegate before starting the SDK as shown in the following example:

Swift

Distribute.delegate = self;

Here is an example of the delegate implementation that replaces the SDK dialog with a custom one:

Swift

func distribute(_ distribute: Distribute, releaseAvailableWith details: ReleaseDetails) -> Bool {

  // Your code to present your UI to the user, e.g. an UIAlertController.
  let alertController = UIAlertController(title: "Update available.",
                                        message: "Do you want to update?",
                                 preferredStyle:.alert)

  alertController.addAction(UIAlertAction(title: "Update", style: .cancel) {_ in
    Distribute.notify(.update)
  })

  alertController.addAction(UIAlertAction(title: "Postpone", style: .default) {_ in
    Distribute.notify(.postpone)
  })

  // Show the alert controller.
  self.window?.rootViewController?.present(alertController, animated: true)
  return true;
}

In case you return YES/true in the above method, your app should obtain user's choice and message the SDK with the result using the following API.

Swift

// Depending on the user's choice, call notify() with the right value.
Distribute.notify(.update);
Distribute.notify(.postpone);

If you don't call the above method, the releaseAvailableWithDetails:-method will repeat whenever your app is entering to the foreground.

3. Execute code if no updates are found

In cases when the SDK checks for updates and doesn't find any updates available newer than the one currently used, a distributeNoReleaseAvailable: from MSACDistributeDelegate delegate callback is invoked. This allows you to execute custom code in such scenarios.

Here are examples which show how to display alert UI when no updates are found:

Swift

  func distributeNoReleaseAvailable(_ distribute: Distribute) {
    let alert = UIAlertController(title: nil, message: "No updates available", preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
    self.window?.rootViewController?.present(alert, animated: true)
  }

Enable or disable App Center Distribute at runtime

You can enable and disable App Center Distribute at runtime. If you disable it, the SDK won't provide any in-app update functionality but you can still use Distribute service in App Center portal.

Swift

Distribute.enabled = false

To enable App Center Distribute again, use the same API but pass YES/true as a parameter.

Swift

Distribute.enabled = true

The state is persisted in the device's storage across application launches.

Note

This method must only be used after Distribute has been started.

Check if App Center Distribute is enabled

You can also check if App Center Distribute is enabled or not:

Swift

var enabled = Distribute.enabled

Note

This method must only be used after Distribute has been started, it will always return false before start.

Don't initialize App Center Distribute during development

If in private mode, App Center Distribute will open up its UI/browser at application start. While this is an expected behavior for your end users, it could be disruptive for you during the development stage of your application. We don't recommend initializing Distribute for your DEBUG configuration.

Swift

#if DEBUG
    AppCenter.start(withAppSecret: "{Your App Secret}", services: [Analytics.self, Crashes.self])
#else
    AppCenter.start(withAppSecret: "{Your App Secret}", services: [Analytics.self, Crashes.self, Distribute.self])
#endif

Perform clean up right before the application closes for update

Implement the DistributeDelegate protocol and register the delegate as shown in the following example:

Swift

Distribute.delegate = self;

The distributeWillExitApp: delegate method will be called right before the app gets terminated for the update installation:

Swift

func distributeWillExitApp(_ distribute: Distribute) {
  // Perform the required clean up here.
}

How do in-app updates work?

Note

For in-app updates to work, an app build should be downloaded from the link. It won't work if installed from an IDE or manually.

The in-app updates feature works as follows:

1. This feature will ONLY work with builds that are distributed using App Center Distribute service. It won't work when the debugger is attached or if the iOS Guided Access feature is turned on..

2. Once you integrate the SDK, build a release version of your app and upload it to App Center, users in that distribution group will be notified for the new release via an email.

3. When each user opens the link in their email, the application will be installed on their device. It's important that they use the email link to install the app - App Center Distribute doesn't support in-app-updates for apps that have been installed from other sources (e.g. downloading the app from an email attachment). When an application is downloaded from the link, the SDK saves important information from cookies to check for updates later, otherwise the SDK doesn’t have that key information.

4. If the application sets the track to private, a browser will open to authenticate the user and enable in-app updates. The browser won't open again as long as the authentication information remains valid even when switching back to the public track and back to private again later. If the browser authentication is successful, the user is redirected back to the application automatically. If the track is public (which is the default), the next step happens directly.

   • On iOS 9 and 10, an instance of SFSafariViewController will open within the app to authenticate the user. It will close itself automatically after the authentication succeeded.
   • On iOS 11, the user experience is similar to iOS 9 and 10 but iOS 11 will ask the user for their permission to access login information. This is a system level dialog and it can't be customized. If the user cancels the dialog, they can continue to use the version they're testing, but they won't get in-app-updates. They'll be asked to access login information again when they launch the app the next time.

5. A new release of the app shows the in-app update dialog asking users to update your application if it's:

   • a higher value of CFBundleShortVersionString or
   • an equal value of CFBundleShortVersionString but a higher value of CFBundleVersion.
   • the versions are the same but the build unique identifier is different.

Tip

If you upload the same ipa a second time, the dialog will NOT appear as the binaries are identical. If you upload a new build with the same version properties, it will show the update dialog. The reason for this is that it's a different binary.

How do I test in-app updates?

You need to upload release builds (that use the Distribute module of the App Center SDK) to the App Center Portal to test in-app updates, increasing version numbers every time.

1. Create your app in the App Center Portal if you haven't already.
2. Create a new distribution group and name it so you can recognize it's meant for testing the in-app update feature.
3. Add yourself (or all people who you want to include on your test of the in-app update feature). Use a new or throw-away email address for this, that wasn't used for that app on App Center. This ensures that your experience is close to the experience of your real testers.
4. Create a new build of your app that includes App Center Distribute and contains the setup logic as described below. If the group is private, don't forget to set the private in-app update track before start using the updateTrack property.
5. Click on the Distribute new release button in the portal and upload your build of the app.
6. Once the upload has finished, click Next and select the Distribution group that you created as the Destination of that app distribution.
7. Review the Distribution and distribute the build to your in-app testing group.
8. People in that group will receive an invite to be testers of the app. Once they accept the invite, they can download the app from the App Center Portal from their mobile device. Once they have in-app updates installed, you're ready to test in-app updates.
9. Bump the version name (CFBundleShortVersionString) of your app.
10. Build the release version of your app and upload a new build of your app like you did in the previous step and distribute this to the Distribution Group you created earlier. Members of the Distribution Group will be prompted for a new version the next time the app starts.

Tip

Have a look at the information on how to utilize App Center Distribute for more detailed information about Distribution Groups etc. While it's possible to use App Center Distribute to distribute a new version of your app without adding any code, adding App Center Distribute to your app's code will result in a more seamless experience for your testers and users as they get the in-app update experience.

Disable forwarding of the application delegate's methods calls to App Center services

The App Center SDK uses swizzling to improve its integration by forwarding itself some of the application delegate's methods calls. Method swizzling is a way to change the implementation of methods at runtime. If for any reason you don't want to use swizzling (e.g. because of a specific policy) then you can disable this forwarding for all App Center services by following the steps below:

1. Open the project's Info.plist file.
2. Add AppCenterAppDelegateForwarderEnabled key and set the value to 0. This disables application delegate forwarding for all App Center services.
3. Add the openURL callback in the project's AppDelegate file.

Swift

func application(_ application: UIApplication, open url: URL, sourceApplication: String?, annotation: Any) -> Bool {

  // Pass the URL to App Center Distribute.
  return Distribute.open(url)
}