Android

Callback URL

Callback URL example with Instagram OAuth

One of the use cases of callback URLs is OAuth. Let us do this with an Instagram Login: If the user enters their credentials and clicks the Login button, Instagram will validate the credentials and return an access_token. We need that access_token in our app.

For our app to be able to listen to such links, we need to add a callback URL to our Activity. We can do this by adding an <intent-filter/> to our Activity, which will react to that callback URL. Assume that our callback URL is appSchema://appName.com. Then you have to add the following lines to your desired Activity in the Manifest.xml file:

<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.BROWSABLE"/>
<data android:host="appName.com" android:scheme="appSchema"/> 

Explanation of the lines above:

  • <category android:name="android.intent.category.BROWSABLE"/> makes the target activity allow itself to be started by a web browser to display data referenced by a link.
  • <data android:host="appName.com" android:scheme="appSchema"/> specifies our schema and host of our callback URL.
  • All together, these lines will cause the specific Activity to be opened whenever the callback URL is called in a browser.

Now, in order to get the contents of the URL in your Activity, you need to override the onResume() method as follows:

@Override 
public void onResume() { 
    // The following line will return "appSchema://appName.com".
    String CALLBACK_URL = getResources().getString(R.string.insta_callback);
    Uri uri = getIntent().getData();
    if (uri != null && uri.toString().startsWith(CALLBACK_URL)) {
        String access_token = uri.getQueryParameter("access_token");
    }
    // Perform other operations here.
} 

Now you have retrieved the access_token from Instagram, that is used in various API endpoints of Instagram.


This modified text is an extract of the original Stack Overflow Documentation created by the contributors and released under CC BY-SA 3.0 This website is not affiliated with Stack Overflow