How to check declaration value type?

[PavelTurk]

I need to check if declaration value type is variable. The only way I found is to check it via string, but I don't like.

This is my code:

InstanceMirror instanceMirror = reflector.reflect(object);
var classMirror = instanceMirror.type;
for (var v in classMirror.declarations.values) {
  if (v.runtimeType.toString() == "VariableMirrorImpl") { //This is what I have to do now
  }

}

I tried if (v.runtimeType is VariableMirror) but it didn't work. Could anyone say what is a proper way to do it?

[eernstg]

v is VariableMirror is the relevant test if you want to check whether the run-time type of the object which is bound to v is a subtype of VariableMirror.

The test v.runtimeType is VariableMirror is just another way to write false, because v.runtimeType is a reified type, that is, an object of type Type which is a representation of the run-time type of v, and an object of type Type is never of type VariableMirror (except for completely pathological examples where you want to prove that it can be done ;-).

It's similar to looking at v.getClass().getClass() in Java. You want v.getClass() instead, and in Dart that job is done by is.

In any case, this would allow you to look at all the declarations in the class mirrored by classMirror, and selecting the ones that are variable declarations (static variables or instance variables). I assume this is also what you want to do.

PS: 'value type' is a dangerous phrase to use, because there is a concept known as the 'Future value type' of an async function. For Future<int> f(int i) async { return i; } the future value type is int. So it's better to just talk about the 'type of an object', which is some DeclarationMirror in this case, and then it's unimportant that we used .values in order to get hold of it.

[eernstg]

I'll close this issue, it's working as intended.