Where to start with responsibility-driven design?

Where to start with responsibility-driven design?

Old forum URL: forums.lhotka.net/forums/t/11753.aspx

es org se posted on Monday, December 17, 2012

Hi, there.

I read Rockies documentation about responsibility-driven design. I still don't see the point why we need this. Can anybody give me a good starting point to read from, please. I used google and got some links. I didn't enlighten me much. 


How many do use  this design technique? Coding complex CSLA business objects is a lot of work. Using datacentric design we need fewer of these objects.


Where is the difference between an CSLA object and a  collaboration of objects to do a certain job? 


Please give me your ideas.




RockfordLhotka replied on Monday, December 17, 2012

Today a lot of people are creating what they call a "viewmodel" class to fix their data-centric object models.

If those people had used responsibility driven design to create their object models in the first place, then they wouldn't have to waste all that time and effort designing, coding, and testing viewmodel classes.

Some apps are so trivial that a data-centric object model works fine. And that's OK - trivial apps are trivial and rather boring.

But apps that do anything interesting need objects that are designed to meet the needs of the user, not the shape of the database. Whether you create those objects as your central business model like I recommend, or create them in addition to your data-centric objects and call them a viewmodel, you will end up writing that code.

I suggest you read "Object Thinking" by David West, and "Domain-Driven Design" by Erik Evans to get deeper insight into the ideas of good OO design.

es org se replied on Tuesday, December 18, 2012

Hi, Rocky

Thank you very much of your kind words and your good explanation. What du you think about Object Design: Roles, Responsibilities, and Collaborations written by Rebecca Wirfs-Brock and Alan McKean. Wirfs- Brock coined the term resposibility designed object design. If you talk about responsibility driven object design do you talk about this term or is it general speaking?

Eric Evans talks about DDD. He talks about Services, Value Objects, Entities, Modules, Factories etc. but he doesn't talk about responsibilities. Where is your connection between responsibility driven object design and DDD. The same goes for David West.

Tank you for book recommendations. I already have Eric Evan's book. I ordered David West's book today.



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