Support generic types in a Component/Directive

[frankpepermans]

This occurs when I compile using dart2js,

Say I have a Component defined as such:

class MyComponent<T extends something>

and I want to inject the following property:

final Container<T> myContainer;

I use @Inject(Container) this.myContainer; (generic type is not allowed here)

This generates the following warning:

[Warning from Dart2JS on ...]:
packages\...:
Cannot resolve type 'T'.
(Container<T> myContainer) => new MyComponent(myContainer),
          ^

[matanlurey]

We currently don't retain type information during the compile.

Blocked by #48.

[matanlurey]

Investigating feasibility for 4.0.0. One issue there isn't a way to express this:

@Inject(Container<String>)

/cc @kevmoo Is this something planned for the Dart language in the very near future?

[zoechi]

What about something like @Inject(const InjectionToken(Container, const[String]))

[matanlurey]

This is not planned for 4.0.0 at this time (other lower-hanging fruit).

[matanlurey]

Open question: How should we implement this?

[matanlurey]

We should try to gather internal data on how often generic components are used.

[matanlurey]

I think based on how Dart2 works, this is not likely to happen for V5.

I've marked this to revisit in V6+.