it’s not a horrible violation of DDD it’s a horrible violation of… well… it’s just plain horrible (i say this tongue in cheek) :). First off, your entity becomes dependent on having a repository… that’s not ideal. Ideally you’d want to have your repository create the Person and then assign it everything it needs to … Read more
Active Record Pattern Django is tailored towards the use of the Active Record Pattern as described on this Django Design Philosophy page. Your second example follows this pattern – the model itself has its properties, behaviour and data access contained within. You can still use this pattern in a more DDD-like way, if you push … Read more
Am I misinterpreting the intent of the Repository pattern? I’m going to say “yeah”, but know that me and every person I’ve worked with has asked the same thing for the same reason… “You’re not thinking 4th dimensionally, Marty”. Let’s simplify it a little and stick with constructors instead of Create methods first: Editor e … Read more
I’ve read about CQRS systems that maintain a simple key value store on the command side to represent an application’s state, and others that merely correlate messages (using some sort of saga) and utilise the query store to represent an applications state instead. Either way there’ll no doubt be a persistence technology involved with these … Read more
First of all, there’s no code generation going on, which means: no CGLib, no byte-code generation at all. The fundamental approach is that a JDK proxy instance is created programmatically using Spring’s ProxyFactory API to back the interface and a MethodInterceptor intercepts all calls to the instance and routes the method into the appropriate places: … Read more
In the context of the repository pattern, aggregate roots are the only objects your client code loads from the repository. The repository encapsulates access to child objects – from a caller’s perspective it automatically loads them, either at the same time the root is loaded or when they’re actually needed (as with lazy loading). For … Read more