How do you register a listener as soon as your Flutter app starts?
It's tempting to add the listener callback inside the main method directly.
But that's not a good idea.
Let's figure out a better approach using Riverpod, while keeping our app startup logic neat and tidy. 馃У
First of all, let's create a StreamProvider that we can use to access the input stream. 馃憞
This way we can hide away the singleton and get:
- better separation of concerns
- more testable code
Next, we can create a separate service class that:
- registers a listener (via
ref.listen) - handles all incoming stream events inside a callback
Note that since we have a Ref object, we can access other dependencies if needed. 馃憞
We also need to create a provider for our new service class.
This is easy as we just need to pass ref as a constructor argument. 馃憞
But doing this alone won't create the DynamicLinksService until we access/read it somewhere!
To address this, we can get back to the main method and:
- Create a
ProviderContainer - Use it to read our service class provider
- Replace
ProviderScopewithUncontrolledProviderScope
And voila! 馃弫
Our call to container.read() will ensure that our service class is initialized, and the listener is registered as soon as the app starts.
This approach is scalable too, as we can register/initialize new services with one line of code. 馃憞
That's it! You now have another valuable tool for your developer black belt! 馃
Want more?
My complete Flutter course covers this more in depth, along with many other advanced topics. 馃憞
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