Hello All,

With all the care that must be taken in order to avoid a 'DSLitis', I think that a visual designer (-> graphical DSL) would be of great value for developers using MEF. This designer would allow to:

- Add owned or third-party components (CLR types, COM components or AddIns) to the designer surface.
- Define Contract Types.
- Define Imports of components.
- Define Exports & ExportProperty of components.
- Simulate a binding between the represented components and review composition issues.
- Save the configuration in an XML file that can be later used by a ValueResolver to provide configuration to the CompositionContainer.

The fact that MEF allow composition based on Duck Types & string Meta Data provides some advantages in terms of flexibility, but expose some risk in terms of predictability (hence the 'TryBind' method on the CompositionContainer). Thus, the ability to simulate bindings at design time and view where the issues are would be a great plus in using MEF (of course, we still have to use TryBind at runtime to catch any mistake due to imports that were later added to the released application).

What do you think?

Steve

Hi Steve!

Thanks for the suggestions. We have started working on some ideas around tooling. We are strating with making sure that debugging of composable applications is easy. Longer term, we will think about explicit composition tools.

Thanks.

Hi Steve!

Thanks for the suggestions. We have started working on some ideas around tooling. We are strating with making sure that debugging of composable applications is easy. Longer term, we will think about explicit composition tools.

Thanks.

Indeed, it's maybe a little early to think about the 'graphical stuff' ;o)

How about building applications by moving & composing components with fingers, like Lego bricks, using Microsoft Surface ? Ok, that was the crazy idea of the day :o) lol