Support inheritance for attribute mapping annotations such as NgAttr, NgOneWay, etc.

[wstrange]

The use case I have in mind:

A suite of workflow components. They all share some common attributes (example: workflow-id, workflow-variable, etc.)

I would like to have a base class ( WorkflowBase, for example) that defines these common attributes and then have each of my components inherit from this base class.

[mvuksano]

A question here:

If we have a situation like

class Ann {...}

@Ann() class A {
  @NgOneWay('foo')
   var foo;
}
class B extends A {}
@Ann() class C extends B {
  @NgTwoWay('bar')
   var bar;
}

What happens here... Is foo transfered via B to C or not? @mhevery thoughts?

[wstrange]

If I understand the question - that would be the behaviour I would expect.

That is, I want class B to have Ng* mappings for both 'foo' and 'bar'.

[mvuksano]

I don't think class B can have mapping bar as it does not extend C, in which the bar is defined. The question was if class C should see mapping foo which is defined, indirectly, via B.

[wstrange]

Apologies - I meant class C should have both mappings. Does the additional level of inheritance make it difficult to implement?

[mvuksano]

No, just clarifying the behaviour. I'd expect the same, but wanted to hear what other people thought.

[vicb]

@markovuksanovic have you started working on annotations for hierarchy ?

[mvuksano]

@vicb yes.

[mvuksano]

One more question. If we have:

@NgDirective(selector: '[test]')
class TestDirectiveBase {
  @NgAttr('baseField')
  var baseField;
}

@NgDirective(selector: '[test]')
class TestDirective extends TestDirectiveBase {
  @NgAttr('field')
  var field;
  Element element;

  TestDirective(this.element) {
    element.onClick.listen((e) {
      print(this.baseField);
      print(this.field);
    });
  }
}

There's no point on having NgDirective on base class. I think it would be better if we could just do NgAnnotation. Something like:

@NgAnnotation()
class TestDirectiveBase {
  @NgAttr('baseField')
  var baseField;
}

This would require making NgAnnotation concrete. @mhevery Thoughts?

[mhevery]

Yes, no NgDirective annotation on the base class.

[mvuksano]

Implemented in eee4191 (#829)

[pavelgj]

@markovuksanovic do you have any rough estimate of the bootstrap performance impact of this change? My spidey senses are tingling on this one...