🐛 [firebase_messaging] Silent notifications not handled on iOS

[Johandrex]

Bug report

The issue is regarding silent notifications that are sent from firebase on iOS. When a silent notification is sent through firebase, the android app can handle the notification both in the foreground and background. Silent notifications can however not be handled on iOS, neither in the foreground or background, the app doesn't get any indication of the app receiving the notification.

Steps to reproduce

Steps to reproduce the behavior:

1. From Postman, test to POST the following content to https://fcm.googleapis.com/fcm/send

    "to": "_token",
    "priority": "high",
    "data": {
        "content-available": 1
    },

2. This results in the iOS app not receiving the notification, only the android app can receive the silent notification. However when adding the code down below to the Body, the iOS app will receive the notification. It's however not a silent notification that only can be received when the app is in the foreground
   "notification": { "body": "1" }

Expected behavior

The iOS app should be able to handle silent notifications, just like the android app currently can.

---

Additional context

The bug occurs when using 'firebase_messaging' 11.2.10, flutter 12.2.1 on iOS 15.3.1

---

Flutter doctor

Run flutter doctor and paste the output below:

Click To Expand

/Users/user/Development/flutter/bin/flutter doctor --verbose
[✓] Flutter (Channel stable, 2.10.3, on macOS 12.2.1 21D62 darwin-x64, locale en-SE)
    • Flutter version 2.10.3 at /Users/user/Development/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 7e9793dee1 (13 days ago), 2022-03-02 11:23:12 -0600
    • Engine revision bd539267b4
    • Dart version 2.16.1
    • DevTools version 2.9.2

[!] Android toolchain - develop for Android devices (Android SDK version 32.0.0)
    • Android SDK at /Users/user/Library/Android/sdk
    ✗ cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/macos#android-setup for more details.

[✓] Xcode - develop for iOS and macOS (Xcode 13.2.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.11.2

[✗] Chrome - develop for the web (Cannot find Chrome executable at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[✓] Android Studio (version 2021.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.11+0-b60-7590822)

[✓] Connected device (1 available)
    • Snow (mobile) • XXXX-XXXX• ios • iOS 15.3.1 19D52

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 2 categories.
Process finished with exit code 0

---

Flutter dependencies

Run flutter pub deps -- --style=compact and paste the output below:

Click To Expand

dependencies:
- app_settings 4.1.1 [flutter]
- connectivity_plus 2.2.1 [flutter connectivity_plus_platform_interface connectivity_plus_linux connectivity_plus_macos connectivity_plus_web connectivity_plus_windows]
- cupertino_icons 1.0.4
- device_info_plus 3.2.2 [flutter device_info_plus_platform_interface device_info_plus_macos device_info_plus_linux device_info_plus_web device_info_plus_windows]
- dio 4.0.4 [http_parser path]
- enum_to_string 2.0.1
- firebase_analytics 9.1.2 [firebase_analytics_platform_interface firebase_analytics_web firebase_core firebase_core_platform_interface flutter]
- firebase_core 1.13.1 [firebase_core_platform_interface firebase_core_web flutter meta]
- firebase_crashlytics 2.5.3 [firebase_core firebase_core_platform_interface firebase_crashlytics_platform_interface flutter stack_trace]
- firebase_messaging 11.2.10 [firebase_core firebase_core_platform_interface firebase_messaging_platform_interface firebase_messaging_web flutter meta]
- firebase_performance 0.8.0+7 [firebase_core firebase_core_platform_interface firebase_performance_platform_interface firebase_performance_web flutter]
- flutter 0.0.0 [characters collection material_color_utilities meta typed_data vector_math sky_engine]
- flutter_spinbox 0.8.0 [cupertino_icons flutter meta]
- flutter_svg 1.0.3 [flutter meta path_drawing vector_math xml]
- hand_signature 2.1.1 [flutter flutter_svg]
- http 0.13.4 [async http_parser meta path]
- image_picker 0.8.4+10 [flutter flutter_plugin_android_lifecycle image_picker_for_web image_picker_platform_interface]
- intl 0.17.0 [clock path]
- maps_launcher 2.0.1 [flutter flutter_web_plugins url_launcher]
- provider 6.0.2 [collection flutter nested]
- qr_code_scanner 0.7.0 [js flutter flutter_web_plugins]
- shared_preferences 2.0.13 [flutter shared_preferences_android shared_preferences_ios shared_preferences_linux shared_preferences_macos shared_preferences_platform_interface shared_preferences_web shared_preferences_windows]
- timer_builder 2.0.0 [flutter]
- uuid 3.0.6 [crypto]

dev dependencies:
- flutter_lints 1.0.4 [lints]
- flutter_test 0.0.0 [flutter test_api path fake_async clock stack_trace vector_math async boolean_selector characters charcode collection matcher material_color_utilities meta source_span stream_channel string_scanner term_glyph typed_data]

transitive dependencies:
- args 2.3.0
- async 2.8.2 [collection meta]
- boolean_selector 2.1.0 [source_span string_scanner]
- characters 1.2.0
- charcode 1.3.1
- clock 1.1.0
- collection 1.15.0
- connectivity_plus_linux 1.3.0 [flutter connectivity_plus_platform_interface meta nm]
- connectivity_plus_macos 1.2.1 [connectivity_plus_platform_interface flutter]
- connectivity_plus_platform_interface 1.2.0 [flutter meta plugin_platform_interface]
- connectivity_plus_web 1.2.0 [connectivity_plus_platform_interface flutter_web_plugins flutter]
- connectivity_plus_windows 1.2.0 [connectivity_plus_platform_interface flutter]
- cross_file 0.3.2 [flutter js meta]
- crypto 3.0.1 [collection typed_data]
- dbus 0.7.1 [args ffi meta xml]
- device_info_plus_linux 2.1.1 [device_info_plus_platform_interface file flutter meta]
- device_info_plus_macos 2.2.2 [device_info_plus_platform_interface flutter]
- device_info_plus_platform_interface 2.3.0+1 [flutter meta plugin_platform_interface]
- device_info_plus_web 2.1.0 [device_info_plus_platform_interface flutter_web_plugins flutter]
- device_info_plus_windows 2.1.1 [device_info_plus_platform_interface ffi flutter win32]
- fake_async 1.2.0 [clock collection]
- ffi 1.1.2
- file 6.1.2 [meta path]
- firebase 9.0.2 [http http_parser js]
- firebase_analytics_platform_interface 3.1.1 [firebase_core flutter meta plugin_platform_interface]
- firebase_analytics_web 0.4.0+8 [firebase_analytics_platform_interface firebase_core firebase_core_web flutter flutter_web_plugins js]
- firebase_core_platform_interface 4.2.5 [collection flutter meta plugin_platform_interface]
- firebase_core_web 1.6.1 [firebase_core_platform_interface flutter flutter_web_plugins js meta]
- firebase_crashlytics_platform_interface 3.2.1 [collection firebase_core flutter meta plugin_platform_interface]
- firebase_messaging_platform_interface 3.2.1 [firebase_core flutter meta plugin_platform_interface]
- firebase_messaging_web 2.2.9 [firebase_core firebase_core_web firebase_messaging_platform_interface flutter flutter_web_plugins js meta]
- firebase_performance_platform_interface 0.1.1+1 [firebase_core flutter plugin_platform_interface]
- firebase_performance_web 0.1.0+7 [firebase firebase_core firebase_core_web firebase_performance_platform_interface flutter flutter_web_plugins js]
- flutter_plugin_android_lifecycle 2.0.5 [flutter]
- flutter_web_plugins 0.0.0 [flutter js characters collection material_color_utilities meta typed_data vector_math]
- http_parser 4.0.0 [charcode collection source_span string_scanner typed_data]
- image_picker_for_web 2.1.6 [flutter flutter_web_plugins image_picker_platform_interface]
- image_picker_platform_interface 2.4.4 [cross_file flutter http plugin_platform_interface]
- js 0.6.3
- lints 1.0.1
- matcher 0.12.11 [stack_trace]
- material_color_utilities 0.1.3
- meta 1.7.0
- nested 1.0.0 [flutter]
- nm 0.5.0 [dbus]
- path 1.8.0
- path_drawing 1.0.0 [vector_math meta path_parsing flutter]
- path_parsing 1.0.0 [vector_math meta]
- path_provider_linux 2.1.5 [ffi flutter path path_provider_platform_interface xdg_directories]
- path_provider_platform_interface 2.0.3 [flutter platform plugin_platform_interface]
- path_provider_windows 2.0.5 [ffi flutter path path_provider_platform_interface win32]
- petitparser 4.4.0 [meta]
- platform 3.1.0
- plugin_platform_interface 2.1.2 [meta]
- process 4.2.4 [file path platform]
- shared_preferences_android 2.0.11 [flutter shared_preferences_platform_interface]
- shared_preferences_ios 2.1.0 [flutter shared_preferences_platform_interface]
- shared_preferences_linux 2.1.0 [file flutter path path_provider_linux path_provider_platform_interface shared_preferences_platform_interface]
- shared_preferences_macos 2.0.3 [flutter shared_preferences_platform_interface]
- shared_preferences_platform_interface 2.0.0 [flutter]
- shared_preferences_web 2.0.3 [flutter flutter_web_plugins shared_preferences_platform_interface]
- shared_preferences_windows 2.1.0 [file flutter path path_provider_platform_interface path_provider_windows shared_preferences_platform_interface]
- sky_engine 0.0.99
- source_span 1.8.1 [collection path term_glyph]
- stack_trace 1.10.0 [path]
- stream_channel 2.1.0 [async]
- string_scanner 1.1.0 [charcode source_span]
- term_glyph 1.2.0
- test_api 0.4.8 [async boolean_selector collection meta source_span stack_trace stream_channel string_scanner term_glyph matcher]
- typed_data 1.3.0 [collection]
- url_launcher 6.0.20 [flutter url_launcher_android url_launcher_ios url_launcher_linux url_launcher_macos url_launcher_platform_interface url_launcher_web url_launcher_windows]
- url_launcher_android 6.0.15 [flutter url_launcher_platform_interface]
- url_launcher_ios 6.0.15 [flutter url_launcher_platform_interface]
- url_launcher_linux 3.0.0 [flutter url_launcher_platform_interface]
- url_launcher_macos 3.0.0 [flutter url_launcher_platform_interface]
- url_launcher_platform_interface 2.0.5 [flutter plugin_platform_interface]
- url_launcher_web 2.0.9 [flutter flutter_web_plugins url_launcher_platform_interface]
- url_launcher_windows 3.0.0 [flutter url_launcher_platform_interface]
- vector_math 2.1.1
- win32 2.4.1 [ffi]
- xdg_directories 0.2.0+1 [meta path process]
- xml 5.3.1 [collection meta petitparser]

---

[darshankawar]

@Johandrex
Can you try by setting following:

content-available: true
apns-priority: 5 (for e.g)

And see if it helps ?

[Johandrex]

apns-priority

Sadly, neither

{
    "to": "_token",
    "priority": "high",
    "content-available": true,
    "apns-priority": 5,
    "data": {
        "content-available": 1
    }
}

nor

{
    "to": "_token",
    "priority": "high",
    "data": {
        "content-available": true,
        "apns-priority": 5
    }
}

works.

[darshankawar]

@Johandrex
Since you are trying on iOS, can you try using getAPNSToken() ?

Also, do make sure you are handling foreground notifications as mentioned in the document: https://firebase.flutter.dev/docs/messaging/notifications#foreground-notifications

[Johandrex]

@Johandrex Since you are trying on iOS, can you try using getAPNSToken() ?

Also, do make sure you are handling foreground notifications as mentioned in the document: https://firebase.flutter.dev/docs/messaging/notifications#foreground-notifications

Thanks for the answer, getAPNSToken() does indeed result in a token. But this can't be sent to firebase through postman as it returns the following error
"error": "InvalidRegistration"

The foreground notifications are handled in the same way as the link explains.

Also, I just want to reiterate that the notifications does reach the phone when "notification": { "body": "1" } is set. However, when removing notification it's not handled by the plugin on iOS, only Android.