Deep linking in Android — Part 1

Published in

AndroidPub

3 min readMar 15, 2018

Image Courtesy- https://wall.alphacoders.com/big.php?i=665092

You: Hey Gagan, I know jack squat about deep linking. Can you please help me out ?
Me: Want to open your app on clicking a URL ? Yes, with deep linking it’s possible. You don’t have to touch the app icon from home screen of your mobile. The app will automatically be launched on clicking a URL. It also allows you to pass the data from URL to app(also known as query params).

As per the official documentation on android developer’s page:

When a clicked link or programmatic request invokes a web URI intent, the Android system tries each of the following actions, in sequential order, until the request succeeds:
- Open the user’s preferred app that can handle the URI, if one is designated
- Open the only available app that can handle the URI
- Allow the user to select an app from a dialog

We need to add intent filters in our app to handle incoming links with the following attributes and elements:
<action>, <data> and <category>. These will let the system know our app can also handle particular type URL’s.

You : Wait ! What ? Particular type of URL’s ? What do you mean by that ?
Me: I meant you will have to mention the scheme, host and pathPrefix in your <data> tag. See the example 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:scheme=”http”
 android:host=”www.example.com"
 android:pathPrefix=”/gizmos” /></intent-filter>

Above example will only handle http://www.example.com/gizmos

You: Well, this looks easy. Is there a way to handle multiple URL’s from the same app ?
Me: Yes, you can do that. You can also add multiple <intent -filter> tags to handle multiple URL’s. You can also add multiple <data> tags in your <intent-filter>(See below example) but it is considered a good practice to mention separate <intent-filter> tags as it enhances readability and clearly explains the intent behind it.

<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:scheme=”http”
 android:host=”www.example.com"
 android:pathPrefix=”/gizmos” /><data android:scheme=”http”
 android:host=”www.example.com"
 android:pathPrefix=”/foobar” /></intent-filter>

It will now handle http://www.example.com/gizmos and http://www.example.com/foobar

You: Yeah ! I am starting to feel a little confident about it. Wait, you also mentioned something about passing data from URL to app. How about that ?
Me: Yeah right, we can do that as well. Below is the sample URL with dummy data passed along with it:

http://www.example.com/gizmos?data=12345

Now we need to handle it in our activity’s onCreate() method. Just add these lines after setContentView()

Intent intent = getIntent();
Uri data = intent.getData();

You: Thanks a lot Gagan. I feel a lot better now.

Me: Bonus tip- You can have custom schemes as well like abc in place of http or https. See below example for this URL- abc://www.example.com/gizmos

<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:scheme=”abc”
 android:host=”www.example.com"
 android:pathPrefix=”/gizmos” /></intent-filter>

That’s all. I tried to make this tutorial a little interesting. Hit applaud if you found it helpful.

Cheers !!!

Deep linking in Android — Part 1

Written by Gagan Batra