Reuse of legacy software by WinRT and Metro (Windows 8) (Portable Libraries part 2)

 

This is a follow up to my previous post Create a Metro App in F# (NOT).

Things become quit complex if you want to reuse your windows legacy software. In this case legacy has a positive connotation. Legacy software is an asset of you and/or your company.

Suppose one want to reuse it and make it available for a Metro app on Windows 8 what are your options? After watching some of the build presentations:

• Windows Runtime internals: understanding "Hello World" by Matt Merry
• Being pragmatic by leveraging existing code in Metro style apps by Jason Olson
• A .NET developer's view of Windows 8 app development by Krzysztof Cwalina
• Ten Tips When Writing a Hybrid Language Metro style Application by Brent Rector
• Using the Windows Runtime from C# and Visual Basic by Harry Pierson and Jesse Kaplan

 

I came up with the following flow chart:

 

So:

• You can reuse html, css and JavaScript.
• I am not an expert on C++, COM, etc. so I do not know.
• If you have only a dll you cannot use it.
• If you have source code that references a language dll (like F#) or have no options today. This will change when the final product becomes available.
• If you want to create a Metro Style project in C++ or JavaScript you can reuse your components code by fixing issues and recompile it to a WinMD file (WinRT component). Some issues can be exposing:
  • non WinRT types
  • non sealed classes
  • non system provided generic types
• If you want to create a Metro Style project and this is one of the .NET languages you can reuse your components code by fixing issues and recompile it to a dll. Some issues can be:
  • Streams

 

Disclaimer: This is my current understanding, based on the presentations I viewed. If you have other information available please leave a note in the comments.