FileProvider declared in image_picker collides with app-declared FileProvider, compilation fails (Android) #20481
Description
The image_picker plugin declares a FileProvider in its android manifest:
For my app I also needed a FileProvider, so I declared one in the manifest of my Flutter android module:
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="boformer.downloadtest.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths"/>
</provider>The problem is that when the manifest is merged with the app's manifest and other plugin manifests, it collides with other FileProvider declarations. Compilation fails:
Launching lib/main.dart on Android SDK built for x86 in debug mode...
Initializing gradle...
Resolving dependencies...
Running 'gradlew assembleDebug'...
/Users/felix/development/download_test/android/app/src/main/AndroidManifest.xml:21:13-65 Error:
Attribute provider#android.support.v4.content.FileProvider@authorities value=(boformer.downloadtest.provider) from AndroidManifest.xml:21:13-65
is also present at [:image_picker] AndroidManifest.xml:14:13-74 value=(boformer.downloadtest.flutter.image_provider).
Suggestion: add 'tools:replace="android:authorities"' to <provider> element at AndroidManifest.xml:19:9-27:20 to override.
/Users/felix/development/download_test/android/app/src/main/AndroidManifest.xml:26:17-55 Error:
Attribute meta-data#android.support.FILE_PROVIDER_PATHS@resource value=(@xml/provider_paths) from AndroidManifest.xml:26:17-55
is also present at [:image_picker] AndroidManifest.xml:19:17-72 value=(@xml/flutter_image_picker_file_paths).
Suggestion: add 'tools:replace="android:resource"' to <meta-data> element at AndroidManifest.xml:24:13-26:57 to override.
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:processDebugManifest'.
> Manifest merger failed with multiple errors, see logs
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 14s
Finished with error: Gradle build failed: 1
There can only be one declaration for each FileProvider subclass. That means to declare multiple file providers without collisions, one must create a (empty) subclass of android.support.v4.content.FileProvider and use that as the provider name in the manifest.
In my opinion, android.support.v4.content.FileProvider should be reserved for the app itself so that developers can easily add a file provider to their app, without subclassing FileProvider. It's also used in the Android documentation and in StackOverflow answers.
image_picker and other plugins should subclass FileProvider to prevent collisions (also collisions between plugins).
This issue describes a similar problem in an Android library.
Changes to image_picker would be minimal:
<provider
android:name="io.flutter.plugins.imagepicker.ImagePickerFileProvider"
android:authorities="${applicationId}.flutter.image_provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/flutter_image_picker_file_paths"/>
</provider>package io.flutter.plugins.imagepicker;
import android.support.v4.content.FileProvider;
public class ImagePickerFileProvider extends FileProvider {}