CODEWITHSUNDEEP
flutterdart
BeniaminoBaggins
BeniaminoBaggins

Reputation: 12433

Dart - Allow SubType to Implement class method or else have it be null

How do I specify that subtypes can implement a function if they want to, but if they don't implement it, it will be null?

I want to do this:

// base class member
Future<dynamic> vpSubmitLocalMethod()?;

// in a function in the same base class:

if (vpSubmitLocalMethod != null) {
  vpSubmitLocalMethod!();
}

Is this possible? Or if not, what is the cleanest solution? Or do I have to create an extra boolean class member to use in the if statement?

Upvotes: 1

Views: 157

Answers (1)

dangngocduc
dangngocduc

Reputation: 1814

You can try this solution: create

typedef SubmitLocal = Future Function();

In your class, create a field :

SubmitLocal? vpSubmitLocalMethod;

And you use :

vpSubmitLocalMethod?.call();

Upvotes: 1

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