Separatint User Interface Code

http://www.martinfowler.com/ieeeSoftware/separation.pdf

 

Keep your user interface code separate from everything else.

 

Why do this?

1. It lets different people work on the separate pieces, which is useful when people want to hone more specialized skills.

2. Multiple presentations are possible

3. Pulling away the domain code also makes it easier to spot - and avoid - duplication in domain code

4. Presentations, particularly WIMPs and browser-based presentations, can be very difficult to test.

 

The difficulties

So why don't programmers seperate their code? Much of the reason lies in tools.

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The biggest presentation tool has been the family of platforms for developing WIMP interfacees: Visual Basic, Delphi, Powerbuilder, and the like.

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but the tools don't provide any place to extract the domain code.

 

citing

So, if you write an application with a WIMP (windows, icons, mouse, and pointer) GUI, you should be able to write a command line interface that does everything that you can do through the WIMP interface—without copying any code from the WIMP into the command line.