How to get subtypes using `DartType` class from the `analyzer`?

Question

How can I get the subtypes of an element using the class DartType from the analyzer package?

score 5 · Accepted Answer · answered Jan 20 '17 at 01:53

5

For those wondering, the DartType class is a statically resolved type that is created by the analyzer package, Dart's static tooling package. The author is asking how they can get other types given a DartType - I think you mean super types, i.e. types that you inherit or implement.

(If you simply wanted to check if the DartType is a subtype of something, you could use isSubtypeOf)

We can get a hold of the Element that the DartType originates from, and then, if it is a ClassElement, simply return all of the super types, otherwise perhaps default to an empty list:

import 'package:analyzer/dart/element/element.dart';
import 'package:analyzer/dart/element/type.dart';

/// Returns all sub-types of [type].
Iterable<DartType> getSubTypes(DartType type) {
  final element = type.element;
  if (element is ClassElement) {
    return element.allSupertypes;
  }
  return const [];
}

This is in analyzer version 0.29.3.

answered Jan 20 '17 at 01:53

matanlurey

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sorry, I want the subtypes of a generic type, ie: `List` I want `String`. – Luis Vargas Jan 20 '17 at 01:55
should I change the question? – Luis Vargas Jan 20 '17 at 01:55
1

That or ask another one - I imagine this will be useful for someone :) – matanlurey Jan 20 '17 at 01:56
other question: http://stackoverflow.com/questions/41754912/how-to-get-the-subtypes-of-a-generic-type-using-darttype-from-analyzer-packa – Luis Vargas Jan 20 '17 at 02:03
1

@matanlurey do you know how to get DartType from a Type ? Because on my generator I want to use isSubtypeOf but can't as I only have the Type not the dartType to compare to – jaumard Mar 01 '19 at 09:32

How to get subtypes using `DartType` class from the `analyzer`?

1 Answers1