The Service Layer is meant to act as an API to your domain model. That means anything external to the model should be going through the Service Layer to interact with your model. Your controller should never even know that DAO and Gateway objects exist at all.
When you're sending messages to objects internally within the model, you have more options as far as whether calls should be going through other Service Layer objects or not. Personally, my Service Layer objects will interact with things like a Gateway if they are directly managed by the Service object. So if I have a UserService, and a UserGateway, then it is acceptable coupling for the UserService to make calls to the UserGateway since the gateway is actually a property of the service. However, if I also have a LoginService and it needs to find out something about a User, I prefer to have the LoginService talk only to the UserService. I want to keep it as the single authoritative interface for data or behavior related to Users. I would be reluctant to let the LoginService make requests directly to the UserGateway as this breaks encapsulation and increases coupling, meaning if I need to change how my UserGateway works, I now have to change the UserService but also have to figure out if I need to change the LoginService as well. On Mon, Apr 28, 2008 at 7:20 AM, wkolcz <[EMAIL PROTECTED]> wrote: > Thanks. I guess then it might be better to ask when is it most appropriate > to interact the controller with a Service Object and when to interact with a > bean to utilize the DOA and Gateway objects? I need to learn what is the > strong point and weakness of both so I can know when a situation warrants > one over the other. > > Wish there was a real one-stop-resource out there to cover OOD for CF and > all the design patterns. :-) > > ------------------------------ > *From*: "Brian Kotek" <[EMAIL PROTECTED]> > *Sent*: Sunday, April 27, 2008 9:07 PM > *To*: [email protected] > *Subject*: [CFCDEV] Re: Noobie Question > > Wally, you're basically asking the question "what is the best way to build > my object model?", which is essentially an unanswerable question because the > answer it "it depends". > > When using Reactor and ColdSpring and Model-Glue, how do you know that > "this way is the better way of doing things"? And what answer do you expect > to the question "is it right to assume one should use the Service Object to > interact with the bean, the DAO, and the Gateway?" > > The questions that you're asking are so dependent on what your application > actually needs to do, and the forces at play in your specific environment, > that they are nearly meaningless without far more context. In some cases the > answer will be yes and in some, the answer will be no. > > > On Sun, Apr 27, 2008 at 9:37 PM, Wally Kolcz <[EMAIL PROTECTED]> wrote: > > > Another thing. Using Illudium PU-36, it creates a Service Object. After > > reading more up on it, is it right to assume one should use the Service > > Object to interact with the bean, the DAO, and the Gateway? > > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "CFCDev" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/cfcdev?hl=en -~----------~----~----~----~------~----~------~--~---
