Re: One-to-one ARs and an identity crisis

After spending some more time at the whiteboard, I think the modeling could go either of these two ways.

1. Original model
SlideShow is part of Course as well as Sessions. This makes for a fat Course AR and the one-to-one is still a smell :-/

2. Potential model
Perhaps SlideShow is a TYPE of Course. It is an OnlineCourse. And Session would be a ClassroomCourse. You could call ClassroomCourse->getUpcomingSessions(), or OnlineCourse->getSlideShow() (or model it so that OnlineCourse itself *is* the SlideShow; thus you would have OnlineCourse->getNextSlide(), etc.). 

I'm still very interested in what others think about this.

Thanks!
Ray

--- In [email protected], "raymond_kolbe" <rkolbe@...> wrote:
>
> I'm going to be honest, I have a couple of hunches about what my
> issue(s) may be, but need some help.
> I have Course, SlideShow, TestMaster, and Session entities. I *thought*
> that Course, SlideShow, and Session were their own ARs, and TestMaster
> was part of SlideShow. Here's why:
> A Course is a simple container with a CourseId that has a description
> and "Offerings". Offerings is a simple value object. It answers the
> questions "is the course available online" and "is the course available
> in the classroom". That's it.
> However, a SlideShow *only* exists if the course is available online
> (more accurately it is only "enabled" if offered online). A SlideShow is
> a one-to-one with the course. Currently I create the SlideShow when the
> event "CourseOfferingsChanged" is triggered and add it to the repository
> (persistence uses transactions and UoW). Also, I'm not sure what the
> identity of a slide show is. I have been using the Course ID--this is
> how I currently look up the SlideShow from the repository.
> How can SlideShow be its own AR? I am updating 2 ARs (read: what I
> thought/think were/are 2 ARs) in a single transaction, and SlideShow
> *only* exists when the Course exists AND Offerings contains the option
> "is online".
> Also note that in-classroom sessions are accessed via the repository and
> created via client code using simple class construction (e.g. new
> Session($courseId, $date, $duration, $signupClosesOn, etc...)).
> Q. Am I correct in thinking that SlideShow as its own AR is a smell?
> Q. How does one reconcile this relationship?
>




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