receive_intent_android34/README.md

receive_intent

A Flutter plugin to pass Android Intents to the Flutter environment.

Intent in Android is the "payload" for the communication between and within apps. This plugin passes the Intent, that "started" the Activity to the flutter environment. It also passes any "new Intents" that are received (via Activity.onNewIntent) while the Activity is already "started".

If the Intent was "started" via startActivityForResult, then this plugin also sends additional information (package name and app signature) about the "calling" Android Component, and can send "result" back (via Activity.setResult) to it.

This plugin is in active development. Any contribution, idea, criticism or feedback is welcomed.

Quick links

package	https://pub.dev/packages/receive_intent
Git Repo	https://github.com/daadu/receive_intent
Issue Tracker	https://github.com/daadu/receive_intent/issues

Use cases

• OAuth based App Flip - This was the initial motivation for this plugin. The plugin can be used to pass the Intent sent by Google App to the flutter environment - where the consent UI is shown - once it is authorized (or not), the result is sent back to the Google App.
• Deeplink/Applink - This plugin is a generic implementation of uni_links plugin. While this plugin passes "any" Intents, uni_links only passes app-link/deep-link Intents.
• Receive Share Intents - This plugin is a generic implementation of receive_sharing_intent plugin. While this plugin passes "any" Intents, receive_sharing_intent only passes "android.intent.action.SEND" (or related) Intents.
• In general, if you want other apps to "start" your app, then this plugin can pass the Intent that "triggered" it to the flutter environment of the app. These Intent will give the app understanding of why the app was started. Check Getting started section to implement this.

Getting started

Add <intent-filter> to AndroidMainfest.xml

You need to add <intent-filter> to android/app/src/main/AndroidManifest.xml file:

<manifest ...>
  <!-- ... other tags -->
  <application ...>
    <activity ...>
      <!-- ... other tags -->
      
      <!-- Describe Intent your app can receive with <intent-filter>  -->
      <intent-filter>
        <action android:name="RECEIVE_INTENT_EXAMPLE_ACTION" />
        <category android:name="android.intent.category.DEFAULT"/>
      </intent-filter>
    </activity>
  </application>
</manifest>

In this example we want to receive Intent with action matching RECEIVE_INTENT_EXAMPLE_ACTION literal. This <intent-filter> should be added to the Activity that extends FlutterActivity (for project generated from template it is MainActivity).

<intent-filter> describes, what Intent the Activity is capable to recevie. To read more about "Intent and Intent Filter", encourage you to check official docs from Android.

Recevie and handle Intent that launched the Activity in Flutter

Inside flutter code, you can call ReceiveIntent.getInitialIntent() to get the Intent that started the Activity:

import 'package:receive_intent/receive_intent.dart';
// ...

  Future<void> _initReceiveIntent() async {
    // Platform messages may fail, so we use a try/catch PlatformException.
    try {
      final receivedIntent = await ReceiveIntent.getInitialIntent();
      // Validate receivedIntent and warn the user, if it is not correct,
      // but keep in mind it could be `null` or "empty"(`receivedIntent.isNull`).
    } on PlatformException {
      // Handle exception
    }
  }
  
// ...

Listen for any new Intent while the Activity is already running

To listen to new Intent while the Activity is running, you can use the ReceiveIntent.receivedIntentStream stream:

import 'package:receive_intent/receive_intent.dart';
// ...
  StreamSubscription _sub;
  
  Future<void> _initReceiveIntentit() async {
    // ... check initialIntent

    // Attach a listener to the stream
    _sub = ReceiveIntent.receivedIntentStream.listen((Intent? intent) {
      // Validate receivedIntent and warn the user, if it is not correct,
    }, onError: (err) {
      // Handle exception
    });

    // NOTE: Don't forget to call _sub.cancel() in dispose()
  }
// ...

Send result to the calling Activity (Optional)

If the calling Activty has "started" this activity with startActivityWithResult then you can send back result to that activity when ready with ReceiveIntent.setResult:

import 'package:receive_intent/receive_intent.dart';
// ...

  Future<void> _setActivityResult() async {
    // ...
    await ReceiveIntent.setResult(kActivityResultOk, data: {"sum": 123})
  }
// ...

To read more about "Starting Activities and Getting Results" pattern, encourage you to check official docs from Android.

Additionaly, in the case of activity started with startActivityWithResult, the Intent object will also have package name (intent.fromPackageName) and app signautres (intent.fromSignatures) of the calling activity. This could be used to validate the calling app, so that sensitive information is not given to unintendent apps.

Tools to test it

You can test this with either adb or Intent Test app form Playstore.

adb

To invoke (start) our FlutterAcitivity with RECEIVE_INTENT_EXAMPLE_ACTION intent action name as mentioned in example <intent-filter> above:

adb shell 'am start -W -a RECEIVE_INTENT_EXAMPLE_ACTION -c android.intent.category.DEFAULT'

If you don't have adb in your path, but have $ANDROID_HOME env variable then use "$ANDROID_HOME"/platform-tools/adb ....

Note: Alternatively you could simply enter an adb shell and run the am commands in it.

Check example app

To know more or to get the working code check the example app.

Todo

• Document API references properly
• Receive Intent for non-Activity based intent-filter (BroadcastReceiver, Service)
• Automatic testing

Contribute

Check the Todo section above, before you begin with any contribution.

1. You'll need a GitHub account.
2. Fork the repository.
3. Pick an issue to work on from issue tracker.
4. Implement it.
5. Add your name and email in authors section in pubspec.yaml file.
6. Send merge request.
7. Star this project.
8. Become a hero!!

Features and bugs

Please file feature requests and bugs at the issue tracker.

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Harsh Bhikadia 🤔 💻

Mateusz Soszyński 💻

Chris Tomlinson 💻

eric-nextsense 🐛 💻

Tanay Neotia 🐛 💻

Geert-Johan Riemer 💻

Derrick Gibelyou 💻

This project follows the all-contributors specification. Contributions of any kind welcome!