Solving Problems with the Firebase Messaging Package on Flutter

Solving Problems with the Firebase Messaging Package

While setting up and testing the Firebase Messaging package for message reception, I came across an issue. The onMessage function worked perfectly, but the onResume and onLaunch functions weren't operating as I had expected. Despite thorough research into various issues posted on the package repository, I was unable to find a definitive cause of the problem, which made it difficult to resolve.

Uncovering the Root Cause

Through extensive investigation, I realized that the problem wasn't with the package itself, but rather with how I was using Firebase Cloud Messaging (FCM) on the server side. I had not migrated to FCM v1 and was still using the older HTTP-based downstream method. To fix this, I needed to set the click_action value within each message's notification to FLUTTER_NOTIFICATION_CLICK, as per an example I found.

The Solution

If you're experiencing similar issues with the onResume or onLaunch functions in Firebase messaging not working correctly, consider whether you have been sending messages directly from the Firebase console. If so, setting up your own server could be the solution. By including the correct click_action in your server setup and trying again, you can effectively resolve this issue.

I hope this troubleshooting guide helps you successfully implement Firebase messaging in your project.