I appreciate you taking the time to blog your experience with this topic :)
/Mark On Jan 27, 3:35 pm, Markus Zywitza <markus.zywi...@gmail.com> wrote: > ICriteria relates to Specification like ActiveRecord-types to a domain > model. ICriteria may resemble a specification, but it is actually a > query in a fluent API format. If you want to go all the way, then you > need a real specification model that is used to create queries by the > repository. > > Also, I blogged about my experiences with AR+DDD. You might find it > useful for your own decision what to do. > > http://mortslikeus.blogspot.com/2009/01/active-record-and-ddd.html > > -Markus > > 2009/1/27 Mark Jensen <don...@gmail.com>: > > > > > This would actually been my next question :) > > > usually I would do the same thing you talk about and encapulate the > > quiery, but from what I understand with DDD (not saying that this only > > goes for DDD, i have just never heard before I started on DDD), you > > are allowed to make this sort methods. > > > using the Criterion as a parameter for method like the FindOne(), > > seems to follow the guideline/rule of the SPECIFICATION Pattern and > > thereby add flexiblity to the design. > > > The argument to us the FindMeSomething(iNeed) and thereby making hard- > > coded quires, should be that the client would have done this anyway. > > So it makes sense to make hardcoded quires because they give you some > > convience > > > But the issue with FindMeSomething(iNeed), is that the developer need > > to understand the inner workings/implications of using a encapsulated > > metod... meaning that, if they dont know about how the method quiries > > the database, they might pull to much data into memory and thereby > > bringing the system down. > > > you could probably refactor yourself out of this problem, but still... > > > /Mark > > > On Jan 26, 3:55 pm, Markus Zywitza <markus.zywi...@gmail.com> wrote: > >> Code from the article you linked: > > >> public virtual T FindOne(params ICriterion[] criteria) > >> { > >> return ActiveRecordMediator<T>.FindOne(criteria); > >> } > > >> This moves the responsibility for creating a particular query from the > >> repository to the higher layers, who need to know about an aggregate's > >> inner workings. Once you start to optimize for n+1 etc., this > >> knowledge of the persistence is rather deepened than encapsulated. > >> A better approach is to create a bunch of > >> FindByWhateverMyAppNeeds(string iNeedThat). That's ugly, but > >> encapsulates persistence within the repository. > > >> -Markus > > >> 2009/1/26 Mark Jensen <don...@gmail.com>: > > >> > Hi Markus > > >> > Could you explain the contradictions a bit more for me? > > >> > thanks :) > > >> > On Jan 26, 1:22 pm, Markus Zywitza <markus.zywi...@gmail.com> wrote: > >> >> You lose nothing with dropping ActiveRecordBase but convenience. > > >> >> But keep in mind: > > >> >> 1) AR classes without ARBase make good DTOs, but still bad domain > >> >> classes. > >> >> 2) Generic repositories are an antipattern. A repository should > >> >> encapsulate the knowledge of an aggregate's persistence details. That > >> >> contradicts with ready-to-use-plugs for LINQ or criteria queries. > > >> >> If you need to do DDD, use AR as DTO and map it to the domain layer. > >> >> If you are doing this because DDD has a momentary hype, just don't do > >> >> it at all. The "Domain Model" is not the only enterprise pattern that > >> >> yields maintainable software. > > >> >> -Markus > > >> >> 2009/1/26 Mark Jensen <don...@gmail.com>: > > >> >> > Hi > > >> >> > From what i can read on the internet people do really like this > >> >> > combination due to the placement of the persitance logic. > > >> >> > how ever, i know that Castles AR has something callsed > >> >> > ActiveRecordMediator which seems to be the solution to the problem > >> >> > above. (i also know ayendes rhino commons which also have an > >> >> > implementation of the repository pattern). > > >> >> > The questions are. > > >> >> > 1. Will i lose something if i stop inheritting from ActiveRecordBase > >> >> > and use ActiveRecordMediatior instead? (to me it seems like i will get > >> >> > a lot more functionality/control) > > >> >> > 2. Can someone me how to implement the Repository pattern with > >> >> > ActiveRecordMediator. I have found this example here > >> >> >http://www.lostechies.com/blogs/johnteague/archive/2008/05/27/using-d... > > >> >> > but to me it seems like I would have to make a Repository (and inherit > >> >> > from BaseRepository) for every Aggregate and then I need to > >> >> > instantiate the Repository it when i want to use it. > > >> >> > Is there a better way of doing this? > > >> >> > :) > > >> >> > best regards, > >> >> > Mark --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Castle Project Users" group. To post to this group, send email to castle-project-users@googlegroups.com To unsubscribe from this group, send email to castle-project-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/castle-project-users?hl=en -~----------~----~----~----~------~----~------~--~---
