How can I check to see if provided class exists

Question

I am using Provider package in my flutter app.

I am conditionally providing a ChangeNotifier class using provider.

A subsequent build method down the tree wants to check to see if the class exists, and it is not a failure case if it doesn't.

How can I do this using Provider package. Currently when I call...

Provider.of<MyChangeNotifier>(context);

It throws if MyChangeNotifier does not exist up the tree. All I want is a quick and simple check for MyChangeNotifier existence, because it is an expected case.

Solution

As @Scorb mentioned, calling Provider.of<MyChangeNotifier?>(context) with null safety enabled will try to obtain the matching provider and if none are found null will be returned instead of throwing.

Comments

[Calvin Gonsalves]

you can try implementing the second point mentioned in pub.dev/packages/provider/versions/6.0.0-dev/changelog of the latest provider version

[Scorb]

@CalvinGonsalves. You have provided the correct answer. The way to do this is to call Provider.of<MyChangeNotifier?>(context) with nullable types language feature enabled. If you want to write that as the answer, you can get some internet points.

[quantum apps]

hahaha, how did I not figure this one out myself

[felix-ht]

note that you will have to use provider 6.0.0 or later for this to work