> I still have to either manually do it every time, or do something like
> override getStudents() in the Course class (not the _Course) class...
Yeah, that's basically it... we override the getter method for any
relationship we want sorted or filtered or otherwise modified. It's not a
problem for us because we have lots of hand-crafted getter methods in our
terminal classes, building up the bulk of our business logic. One more
method for sorting is insignificant. For you, it sounds like that isn't so
common.
Your original suggestion wasn't a bad one. Let's see, you could implement a
"wedge" class (what the modeler calls a "DataObject Superclass") and
override CayenneDataObject's readProperty(). If the result of
super.readProperty() is instanceof List, and the first element is instanceof
Comparable, you could call Collections.sort() on the List before returning
it.
----- Original Message -----
From: "Todd O'Bryan" <toddobrya..ac.com>
To: <cayenne-use..bjectstyle.org>
Sent: Sunday, March 13, 2005 5:12 PM
Subject: Re: getting a List of Comparables, feature request?
>
> On Mar 13, 2005, at 2:21 PM, Bryan Lewis wrote:
>
> > I don't know how much this will help you, but I'm taking your question
> > as a
> > "best practices" question.
> >
> Thanks for being generous. In spite of my inability to ask it
> correctly, that is kind of the way I meant it. :-)
>
> > When we started rewriting our apps onto a Cayenne+Tapestry base, we set
> > ourselves a rule that there would be no Cayenne-related code in the
> > page
> > classes. No cayenne imports in any source file that also has tapestry
> > imports. This is something we learned from the headaches in our
> > previous
> > WebObjects implementation (even though the model/view separation was
> > moderately good there).
> >
> > This avoids the situation of query code being buried all over the
> > place.
> > The queries are all in the model layer, deployed in a separate
> > model.jar.
> > This gives us maximum reuse of queries. When we want a list to be
> > sorted in
> > a certain way (like a list of countries sorted by name), we do a simple
> > addOrdering() in the one query method. I'm glossing over some
> > details, but
> > you get the idea.
>
> How do you avoid this? Do you have an entirely separate model in
> addition to the classes the Cayenne Modeler creates for you? If so, how
> do you keep it in sync with the Cayenne model? If not, then I think I'm
> doing roughly what you're doing. I have a Course object, say, and I
> want a list of all the students in it, so I call the auto-created
> aCourse.getStudents() method. My problem is that, even though I almost
> always want the Student objects sorted by name, and even made Student
> implement Comparable for this very purpose, I still have to either
> manually do it every time, or do something like override getStudents()
> in the Course class (not the _Course) class so that it does it. Oh, and
> in every other class (Club, Team, Assignment, and numerous others,
> given the fact that almost everything in a school is somehow related to
> a Student) where I might want to getStudents(). And similar issues
> occur with other objects in the model: class sections are almost always
> sorted by period, multiple choice answers are almost always sorted A-E,
> forum posts are almost always sorted by time of post, etc.
>
> Shouldn't something OO-related come to my rescue about right now? Or am
> I doomed to write Collections.sort(theList); over and over again
> throughout the application?
>
> Thanks,
> Todd
>
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