Solving Deep Linking Issues with Chrome Custom Tabs on Android

Why Chrome Custom Tabs Don't Open Other Apps and How to Fix It

Android developers often rely on Chrome Custom Tabs for in-app browsing, but deep linking issues can be a major hurdle. When launching a PayPal payment URL, for example, Chrome prompts users to choose between opening the PayPal app or continuing in the browser. However, this doesn’t happen when using Chrome Custom Tabs. 🤔

Instead of giving users a choice, Chrome Custom Tabs tend to keep everything inside the browser. This means that even if an app is installed and supports deep linking, it might not open as expected. This limitation can be frustrating, especially for apps that rely on seamless payment flows or authentication via external applications.

Interestingly, using a custom scheme like myapp://deeplinkurl/ works correctly. This raises an important question: how can developers enable apps to override the default http scheme inside Chrome Custom Tabs? The solution requires a mix of deep link configuration, intent filters, and possibly some workarounds.

In this article, we’ll explore how to ensure deep linking works as expected with Chrome Custom Tabs. We’ll go through possible solutions, real-world examples, and the best practices to handle this issue efficiently. 🚀

Understanding Chrome Custom Tabs and Deep Linking Challenges

In the world of Android development, Chrome Custom Tabs provide an efficient way to integrate web content into apps while maintaining a native experience. However, when dealing with deep links—especially those requiring redirection to another app, such as PayPal—the expected behavior does not always work as anticipated. Our Java and Kotlin scripts aim to address this issue by leveraging deep linking techniques, intent filters, and optimized methods for launching external applications.

The first script, written in Java, initializes a Chrome Custom Tab and attempts to open a web-based payment page. However, Chrome Custom Tabs do not always trigger the expected deep linking behavior. To solve this, we define an explicit intent using CustomTabsIntent, ensuring that the tab opens as expected while allowing certain flags like Intent.FLAG_ACTIVITY_NEW_TASK to facilitate external app interactions. This flag is crucial in scenarios where the app needs to start a new task rather than opening within the current instance.

For better compatibility, the second script, written in Kotlin, follows a similar structure but optimizes memory management and intent handling using Kotlin’s modern syntax. The approach ensures that if a deep link is registered with the system, it gets the correct priority. Furthermore, error handling and alternative URL schemes (e.g., myapp://deeplinkurl/) are implemented to ensure that fallback mechanisms work properly when standard HTTP-based deep linking fails.

On the backend, our Node.js solution generates deep links dynamically based on query parameters. This method ensures that users are redirected correctly whether they are using PayPal, another payment gateway, or a custom deep link. To validate functionality, Jest-based unit tests verify that the server correctly generates deep links for different scenarios. This is especially useful for handling various user flows, such as authentication or payment completion, where a seamless transition between apps is necessary. 🚀

// Java solution for handling deep linking in Chrome Custom Tabs
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.browser.customtabs.CustomTabsIntent;
public class CustomTabActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        String url = "https://www.paypal.com/checkout";
        openCustomTab(url);
    }
    private void openCustomTab(String url) {
        CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder();
        CustomTabsIntent customTabsIntent = builder.build();
        customTabsIntent.intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        customTabsIntent.launchUrl(this, Uri.parse(url));
    }
}

// Kotlin solution for better deep link handling in Chrome Custom Tabs
import android.content.Intent
import android.net.Uri
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.browser.customtabs.CustomTabsIntent
class CustomTabActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val url = "https://www.paypal.com/checkout"
        openCustomTab(url)
    }
    private fun openCustomTab(url: String) {
        val builder = CustomTabsIntent.Builder()
        val customTabsIntent = builder.build()
        customTabsIntent.intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
        customTabsIntent.launchUrl(this, Uri.parse(url))
    }
}

// Node.js backend to generate deep links dynamically
const express = require('express');
const app = express();
const PORT = 3000;
app.get('/generate-link', (req, res) => {
    const targetApp = req.query.app || 'paypal';
    let deepLink = '';
    if (targetApp === 'paypal') {
        deepLink = 'paypal://checkout';
    } else {
        deepLink = 'myapp://deeplinkurl';
    }
    res.json({ deepLink });
});
app.listen(PORT, () => {
    console.log(`Server running on port ${PORT}`);
});

// Jest test cases for verifying deep link generation
const request = require('supertest');
const app = require('../server');
test('Should return PayPal deep link', async () => {
    const res = await request(app).get('/generate-link?app=paypal');
    expect(res.body.deepLink).toBe('paypal://checkout');
});
test('Should return default deep link', async () => {
    const res = await request(app).get('/generate-link?app=myapp');
    expect(res.body.deepLink).toBe('myapp://deeplinkurl');
});

Enhancing Deep Linking Support in Chrome Custom Tabs

One crucial aspect often overlooked when discussing Chrome Custom Tabs and deep linking is the impact of Android App Links. Unlike traditional deep links, which rely on custom URI schemes (e.g., myapp://deeplinkurl/), Android App Links use verified HTTP-based links. This method allows an app to open directly when a specific URL is clicked, bypassing the need for a user prompt. However, Chrome Custom Tabs do not always respect these settings, causing unexpected behavior.

To work around this limitation, developers can implement a combination of Digital Asset Links and intent filtering. By hosting a JSON file on their domain, developers can associate their website with their Android app, giving it priority when handling links. This prevents Chrome from trapping links that should open in external applications, like PayPal or authentication apps. Additionally, configuring intent-filters in the AndroidManifest.xml ensures that deep links trigger correctly, even when accessed through Chrome Custom Tabs.

Another factor to consider is user experience. Some users prefer having the choice to open a link in a browser or the corresponding app. Implementing a user-friendly prompt using PackageManager.resolveActivity() helps check if an app is installed before attempting to open a deep link. By giving users control over their experience, developers can reduce frustration and ensure seamless navigation between web and mobile applications. 🚀