Create Universal Links for iOS Apps

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Create Universal Links for iOS Apps

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Create Universal Links for iOS Apps

Robin van het Hof

12/02/2018

Intermediate

15 min.

Modify an SAP Cloud Platform SDK for iOS app to accept universal links. This allows users to navigate to your app via a URL sent by email or from a website.

You will learn

In this tutorial, you will learn how to create universal links for use in an iOS app created using the SAP Cloud Platform SDK for iOS Assistant. With universal links, iOS users can tap a link on a website or in an email, and get redirected to your app immediately without opening the link in Safari.

To prepare your app to support universal links, you will create a new (or modify an existing) app ID on Apple Developer Portal, modify the application definition on SAP Cloud Platform mobile service for development and operations, and modify the app’s entitlements in Xcode.

For this tutorial, you can use any iOS app you have previously created with the SAP Cloud Platform SDK for iOS Assistant. However, the screenshots and parameters used in this tutorial are taken from the OfflineDemo app created in tutorial Create an iOS App with Offline Capabilities. If you want to follow this tutorial to the letter, make sure you have finished creating the OfflineDemo app.

Step 1: Register the app on Apple Developer Portal

Log in to the Apple Developer Portal at https://developer.apple.com/ and navigate to Certificates, Identifiers & Profiles. From the pane on the left, navigate to Identifiers > App IDs:

Click the Plus button in the top right to register an App ID.

Provide the following details:

Field Name	Value
App ID Description	`OfflineDemo`
App ID Prefix	This is already filled in. Copy and store this value as you will need it later.
Explicit App ID	selected
Bundle ID	`com.sap.tutorials.demoapp.offlinedemo`

The App ID Description can be anything. The Bundle ID can be found in your Xcode project settings, under the General tab at the Identity panel:

After you have provided the App ID Description and Bundle ID, scroll down to App Services.

Enable the Associated Domains service:

Click Continue to proceed.

Done

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Step 2: Confirm the new App ID

In the next screen, review the settings you have provided:

Scroll down and click Register when done.

Done

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Step 3: Complete the App ID registration

The registration is now complete:

Scroll down and click Done to dismiss the wizard.

Done

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Step 4: Define application link on SAP Cloud Platform

Log on to SAP Cloud Platform mobile service for development and operations cockpit at https://hcpmsadmin-<your_user_id>trial.dispatcher.hanatrial.ondemand.com/ and navigate to Mobile Applications > Native/Hybrid:

Click on the application you want to have universal link support, and from the tab bar, click APIs:

By default, there should be just one QR code listed.

Now navigate to Application Links:

Click the Pencil button in the top right to edit the entry, and provide the following details:

Field Name	Value
Enabled	checked
Team ID	`<your_team_id>`
Bundle ID	`com.sap.tutorials.demoapp.offlinedemo`

The Team ID you have copied in Step 1. You can also find it by going to the Apple Developer Portal and navigate to Membership.

Click OK to save your settings.

Navigate back to APIs. You should now see two QR codes, as well as the generated deep link:

Leave the page open, you will need the generated URL later.

Done

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Step 5: Enable Associated Domains capability to your app

Open your app project in Xcode. In your project’s settings, click the Capabilities tab, and enable Associated Domains.

Enter the following domain:

Field Name	Value
Domain	`applinks:hcpms-<your_user_id>trial.hanatrial.ondemand.com`

Please note the applinks: prefix. It is important you enter it exactly as stated:

Done

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Step 6: Build and deploy the app

If you now build the app, you will notice an <app_name>.entitlements file is created, containing the just added capability:

Continue and deploy the app to your physical device.

Done

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Step 7: Check the AASA file

Once the app is deployed onto your device, it is now running with the added capability.

The way the universal link work is by the associated domain.

In Step 4 you have defined the application link on SAP Cloud Platform mobile service for development and operations. This creates an apple-app-site-association file. This file associates your SAP Cloud Platform mobile service for development and operations account domain with your iOS app.

The generated apple-app-site-association file contains a JSON structure with the App ID and URL path which is used as universal link.

Open a browser to https://hcpms-<your_user_id>trial.hanatrial.ondemand.com/.well-known/apple-app-site-association and you should see the contents of the file:

Note the URL to the apple-app-site-association file starts with https://hcpms-<your_user_id>trial, and not https://hcpmsadmin-<your_user_id>trial

The path listed is the path you will use as universal link in the next step. The asterisk at the end denotes anything. You can for instance add a product id which could directly open an entity with that product ID.

It is up to the app developer to do something meaningful with the provided context. In the next step, you will simply detect the app is launched via a universal link, and log the URL context to the console.

Do you need to be authenticated in order to access the apple-app-site-association file? Yes No

Step 8: Process the universal link context

View Full Instructions

Open your app’s AppDelegate.swift file, and add the following method:

func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([Any]?) -> Void) -> Bool {

    logger.info("SCPms Universal Link called: ")

    if userActivity.activityType == NSUserActivityTypeBrowsingWeb {
        let url = userActivity.webpageURL!
        logger.info(url.lastPathComponent)
        // here you can do whatever you want with the URL components
    }
    return true
}

When you click on a universal link, this hook will be called. The userActivity object contains a webpageURL property, which holds the universal link you clicked.

If you provide some context to the universal link URL, it will then be printed to the console by retrieving the lastPathComponent property of the URL.

Done

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Step 9: Build and deploy the app

Build and deploy the app to your physical device. After it has started, you can dismiss it to the background.

Done

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Step 10: Try the universal link

The easiest way of testing the universal link is to send it via email.

Send an email to yourself containing the link https://hcpms-<your_user_id>trial.hanatrial.ondemand.com/mobileservices/deeplinks/com.sap.tutorials.demoapp.OfflineDemo/start.

In this example, you simply provide the context start, but it can be anything more meaningful of course.

Open the email on your device and click the link:

If you now click it, it should directly open your app without going to Safari first. If you look in the Xcode console, you see it logged the start context it received via the NSUserActivity hook: