Deep linking is when a link sends users directly into a specific point in the app experience, rather than an external website or app homepage.

Whats is Deeplink

• A deep link is a link that takes you to content.
• Deep linking is when a link sends users directly into a specific point in the app experience, rather than an external website or app homepage.
• Most web links are deep links.

Types of Deep Linking

• Custom URI Schemes
• iOS Universal Links
• Android App Links

URI Schemes

• Custom URI schemes were the original form of deep linking for mobile apps.
• They are like creating a “private internet” for your app, with links that look like demo://path/to/content.
• The advantage of custom URI schemes is they are easy to set up.
• The disadvantage is a user’s device only knows about this “private internet” if the corresponding app is already installed, and there is no graceful fallback option by default.

Universal Links

• Apple introduced Universal Links in iOS 9 as a solution to the lack of graceful fallback functionality in custom URI scheme deep links.
• Universal Links are standard web links (https://ankitkumar.dev) that point to both a web page and a piece of content inside an app.
• When a Universal Link is opened, iOS checks to see if any installed app on the device is registered for that domain.
  • If so, the app is launched immediately without ever loading the web page.
  • If not, the web URL (which can be a simple redirect to the App Store) is loaded in Safari.

Android App Links

• Google built App Links as the Android equivalent to iOS Universal Links.
• They operate in a very similar way:
  • a standard web link that points to both a web page and a piece of content inside an app.
• This results in a smoother user experience.
• Since custom URI schemes are still fully supported by every version of Android, App Links have seen very low adoption.

What are we building?

I am declaring deep link URLs for our application, which will open our app from anywhere in the os on Android and iOS devices.

• demo://app/home/:id - This deep link will open the home screen of the app and will pass id as param/props to the home screen
• demo://app/profile/:id - This deep link will open the profile screen of the app and will pass id as param/props to the profile screen
• demo://app/notifications - This deep link will open the notifications screen of the app
• demo://app/settings - This deep link will open the notifications screen of the app

After the implementation of the deep-link, the app will behave as shown here at (0:55) in the video.

Let's do some code now!

Setting up the project

I am assuming that you already have a project in which deep links need to be integrated.

If you don't have any project, I have created a small app with four screens and explained here at (0:05) in the video.

Setting up custom uri scheme for iOS in Xcode

1. Open your react-native(deeplinkreactnavigation) project and go to the ios folder.
2. Open the file with extension .xcworkspace by double-clicking on it. In this project deeplinkreactnavigation.xcworkspace is the file.
3. After opening in Xcode, follow the steps from the screenshot below and add demo to URL Schemes and target name(deeplinkreactnavigation) to the Identifier.

Setting up custom URI scheme for Android in Android Studio

1. Open your react-native(deeplinkreactnavigation) project and go to the android folder.
2. Open file build.gradle with Android Studio.
3. After opening in Android Studio, open Androidmanifest.xml and add intent-filter as shown below.

    <intent-filter>
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />

        <data
          android:host="app"
          android:scheme="demo" />
      </intent-filter>

Handling deep link in react native

1. Create a new file linking.js
2. Add prefixes as an array of demo://app and all deep link URLs as described above to the file as shown below

const config = {
  screens: {
    Home: {
      path: "home/:id",
      parse: {
        id: (id) => `${id}`,
      },
    },
    Profile: {
      path: "profile/:id",
      parse: {
        id: (id) => `${id}`,
      },
    },
    Notifications: "notifications",
    Settings: "settings",
  },
};

const linking = {
  prefixes: ["demo://app"],
  config,
};

export default linking;

Using linking.js in App.js

1. import linking in App.js
2. Add it to NavigationContainer as shown below

<NavigationContainer linking={linking}>
      <MyStack />
</NavigationContainer>

We are done with the coding part

It was easy, wasn't it?

Testing deep link

Its always easy and better to test deep link on physical devices, so

• Install the app on devices(Android or iOS or both)
• Have the deep link URL in any other app
• Tap on deep link URL as a normal URL
• Its should take you our app's respective screen

If you want to test deep link on virtual devices, then

• Install the app on virtual devices(Android or iOS or both)
• Type command npx uri-scheme open demo://app/notifications --android for android to deeplink to notifications screen
• Type command npx uri-scheme open demo://app/notifications --ios for ios to deeplink to notifications screen
• And see the magic

Testing Video at (9:34) in the video.

Originally posted on ankitkumar.dev

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