Last post Jan 28, 2012 03:27 AM by Mikesdotnetting
Jan 28, 2012 02:13 AM|castlehills|LINK
Stephen Walther mentioned about four layer architecture some where, so I'm trying to find some documentation on it. Is the onion architecture that Jeffrey Palermo introduced the same as four layer architecture?
Jan 28, 2012 03:27 AM|Mikesdotnetting|LINK
Traditional ways of layering ASP.NET applications have resulted in separate modules or layers of code that deal with UI, business objects, business logic and data access. Those are the 4 main layers. There may be other conceptual layers - for example services
that might include logging, email management etc, but those are the main 4. They are probably what Stephen Walther was referring to. In tradional Web Forms apps, each layer makes use of the other directly, so they have dependencies on eachother. This makes
Jeffrey Palermo didn't really introduce anything new with his "onion" architecture. It's still based on dividing conceptual layers of logic into separate modules, but he talks about using IOC as a means of connecting them. That reduces the dependencies each
layer has on eachother, and makes testing a lot easier.
Jeffrey wrote his onion architecture articles in 2008 when ASP.NET MVC, and therefore IOC in ASP.NET applications was still very new. I don't thnk he succeeded in getting his particular label (onion) accepted widely.