Should DTOs maintain the object relations? For example if I have two Entities: User and Forum. A user could be the moderator of several Forums, and a Forum of...
7012
acqy_sunnychen
Mar 4, 2008 8:29 am
Another post that seems to be related to my question is here: http://geekswithblogs.net/opiesblog/archive/2006/08/18/88396.aspx please also take a reference to...
7013
Zdeslav Vojkovic
zdeslav_v
Mar 4, 2008 9:37 am
... If the clients of DTO have no use for such a relationship, I don't see why you would have to implement it. In my experience, even when I have bidirectional...
7014
Christophe Herreman
herrodius
Mar 4, 2008 9:47 am
Hi, thx for your suggestion Greg. Implementing an observer mechanism is a trivial task since it is pretty much baked into the language we are using so that...
7015
Alberto Brandolini
ziobrando
Mar 4, 2008 10:11 am
Hi, Scope differs a lot. DDD's target is a specific domain, while SOA is an architectural organization to cross domain boundaries. Some advanced DDD concepts...
7016
Tomas Karlsson
marcellus874
Mar 4, 2008 12:38 pm
"DDD [...] is the basis of SOA" I love it! Can I reuse that phrase in presentations? I mean many SOA approaches are so focused on services so they foreget the ...
7017
Alberto Brandolini
ziobrando
Mar 4, 2008 1:18 pm
Hi, I think that SOA is an architectural perspective that "doesn't care" about how the domains are implemented inside the applications. SOA provides a set of...
7018
david_torontonian
david_toront...
Mar 4, 2008 4:04 pm
... Randy, Do you directly use a repository from a domain object? If yes, it ends up with circular dependency between them. Repository interface can solve this...
7019
Jesse Napier
juice_johnson17
Mar 4, 2008 4:56 pm
David, I think you should ALWAYS use the repository interface. The domain should not have direct references to the repository implementations. ...
7020
david_torontonian
david_toront...
Mar 4, 2008 5:22 pm
Jesse, ... Then for the same reason you should use the entity interface as well. You also need a mechanism that returns a reference to those interfaces. I am...
7021
nichols_mike_s
Mar 4, 2008 5:38 pm
I agree with Zdeslav here. I am the guy who wrote that blog post a looooong time ago and the redundancy in DTOs was frustrating me. However I have discovered...
7022
Pat Maddox
burritoooboy
Mar 5, 2008 2:39 am
... Can you write an object that makes the request and blocks until it gets the response? For example: users = userRepository.loadAll(); loadAll() -> make...
7023
Pat Maddox
burritoooboy
Mar 5, 2008 2:46 am
... Why does the repository return a different object instead of just setting the ID on the existing one? Pat...
7024
m.uithol
Mar 5, 2008 6:07 am
In the way I see it, SOA and DDD are very much compatible. SOA is more concerned with creating services from parts of functionality and being able to couple...
7025
Jesse Napier
juice_johnson17
Mar 5, 2008 8:12 am
David, I'm not sure what you mean by always using the entity interface. Concrete entities live in the domain, repository implementations shouldn't be created...
7026
David Perfors
dnperfors
Mar 5, 2008 8:17 am
That is also possible of course, but for me this now it is more clear that it is really in the database......
7027
Christophe Herreman
herrodius
Mar 5, 2008 9:16 am
Hi Pat, that might be possible although I haven't tested this. The problem I see is that the UI will be locked/frozen until the response is received because...
7028
acqy_sunnychen
Mar 5, 2008 9:25 am
Hi, Thank you all for your replies. So I can make a conclusion that, what the DTOs would look like just depends on the need of transferring data from one layer...
7029
acqy_sunnychen
Mar 5, 2008 9:35 am
Yes, I agree with you on the term "Service". Actually Service in SOA means the enterprise service while the Service in DDD stands for domain services. In my...
7030
acqy_sunnychen
Mar 5, 2008 9:41 am
Yes of course you can! :) SOA is really a good concept to implement the enterprise-level applications. But as I know in many situation we make the wrong use ...
7031
Arun Nair
arun282002
Mar 5, 2008 9:46 am
Hi, A unit of work pattern, if my understanding is correct, is used to minimize roundtrips to database. If this is the case, let's say I create a new object ...
7032
Ertugrul Uysal
ertugrul_uysal
Mar 5, 2008 10:41 am
I would probably check if an object is already in the UOW.NewObjectList before adding it to the UOW.ChangedObjectList, and if it is I would not add it to the...
7033
Jim Amsden
jim_amsden
Mar 5, 2008 1:21 pm
DTOs address a different problem than domain entities. They are used to exchange information between consumers and providers. So they are designed to expose...
7034
Jim Amsden
jim_amsden
Mar 5, 2008 1:25 pm
Or don't put new objects in the ChangedObjectList when they are updated. There should be no need to because the object doesn't yet exist in the database, and...
7035
nichols_mike_s
Mar 5, 2008 4:12 pm
+1 ... designed ... in a ... DTOs on ... exchanged ... the ... in the ... over...
7036
James
jrnail23
Mar 5, 2008 4:15 pm
My former boss (who taught me a hell of a lot) answered a similar question very succinctly for me when I was first starting to explore DDD. I didn't have a...
7037
Greg Young
gumboismadeo...
Mar 5, 2008 5:56 pm
There is nothing wrong with putting async calls there ... I in fact do this on many things that DO operate in memory as they still may take a long time (think...
7038
Tomas Karlsson
marcellus874
Mar 5, 2008 6:38 pm
Hi, In an SOA world, using DDD we still have to deal with the RDBMS as the physical storage. Today I try to promote architectures with a service layer on the...
7039
Bil Simser
sim0099
Mar 5, 2008 7:52 pm
We were having a discussion this morning about readability of code and I wanted to see what people thought. Take an example you have of a repository. Let's say...
7040
Colin Jack
colin.jack
Mar 5, 2008 8:01 pm
... Personally I always use seperate repositories, and to be honest although the repositories may initially be empty you'll quickly end up with custom queries...
