juniorise / android_content_provider

Flutter plugin to use ContentProvider/ContentResolver APIs on Android

android_content_provider

This plugin exposes ContentProvider and related ContentResolver APIs on Android.

Android 11 package visibility

Android 11 introduced a security mechanism that is called a package visibility.

If you are using AndroidContentResolver and trying to access some content provider within a package that is not visible by default, your app will fail to connect to it.

To fix this, add to your AndroidManifest.xml a new <queries> element:

<manifest>
...
    <queries>
        <package android:name="com.example.app" />
    </queries>
...
</manifest>

Configuring AndroidContentProvider

You may ignore these steps if you only want to use AndroidContentResolver.

1. Use the FlutterEngineGroup, provided by the plugin, in your MainActivity to improve performance and reduce memory footprint from engine creation.

   This step is optional, but is strongly recommended.

• Kotlin

import android.content.Context
import com.nt4f04und.android_content_provider.AndroidContentProvider
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine

class MainActivity : FlutterActivity() {
    override fun provideFlutterEngine(context: Context): FlutterEngine? {
        return AndroidContentProvider.getFlutterEngineGroup(this)
                .createAndRunDefaultEngine(this)
    }
}

• Java

import android.content.Context;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import com.nt4f04und.android_content_provider.AndroidContentProvider;

import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;

public class MainActivity extends FlutterActivity {
    @Nullable
    @Override
    public FlutterEngine provideFlutterEngine(@NonNull Context context) {
        return AndroidContentProvider.Companion.getFlutterEngineGroup(this)
                .createAndRunDefaultEngine(this);
    }
}

2. Subclass AndroidContentProvider in native code, setting the authority and Dart entrypoint name you want to use

• Kotlin

package com.example.myapp // <-- replace this with your package

import com.nt4f04und.android_content_provider.AndroidContentProvider

class MyAndroidContentProvider : AndroidContentProvider() {
   override val authority: String = "com.example.myapp.MyAndroidContentProvider"
   override val entrypointName = "exampleContentProviderEntrypoint"
}

• Java

package com.example.myapp; // <-- replace this with your package

import com.nt4f04und.android_content_provider.AndroidContentProvider;

import org.jetbrains.annotations.NotNull;

public class MyAndroidContentProvider extends AndroidContentProvider {
    @NotNull
    @Override
    public String getAuthority() {
        return "com.example.myapp.MyAndroidContentProvider";
    }

    @NotNull
    @Override
    public String getEntrypointName() {
        return "exampleContentProviderEntrypoint";
    }
}

3. Declare your ContentProvider in the AndroidManifest.xml.

• If you want to allow other apps to access the provider unconditionally

<provider
   android:name=".MyAndroidContentProvider"
   android:authorities="com.example.myapp.MyAndroidContentProvider"
   android:exported="true" />

• If you want to make other apps declare <uses-permission>

<provider
   android:name=".MyAndroidContentProvider"
   android:authorities="com.example.myapp.MyAndroidContentProvider"
   android:exported="false"
   android:readPermission="com.example.myapp.permission.READ"
   android:writePermission="com.example.myapp.permission.WRITE" />

4. Subclass AndroidContentProvider in Dart code and override needed methods

import 'package:android_content_provider/android_content_provider.dart';

class MyAndroidContentProvider extends AndroidContentProvider {
  MyAndroidContentProvider(String authority) : super(authority);

  @override
  Future<int> delete(
    String uri,
    String? selection,
    List<String>? selectionArgs,
  ) async {
    return 0;
  }

  @override
  Future<String?> getType(String uri) async {
    return null;
  }

  @override
  Future<String?> insert(String uri, ContentValues? values) async {
    return null;
  }

  @override
  Future<CursorData?> query(
    String uri,
    List<String>? projection,
    String? selection,
    List<String>? selectionArgs,
    String? sortOrder,
  ) async {
    return null;
  }

  @override
  Future<int> update(
    String uri,
    ContentValues? values,
    String? selection,
    List<String>? selectionArgs,
  ) async {
    return 0;
  }
}

5. Create the Dart entrypoint

@pragma('vm:entry-point')
void exampleContentProviderEntrypoint() {
  MyAndroidContentProvider('com.example.myapp.MyAndroidContentProvider');
}