Hi Again, I'm not sure if this needs to be stated or not. But your switch
statement would look something like this.
# switch( true ) {
# case item is IHeightItem:
# //do stuff
# break;
# case item is ILevelItem:
# //do stuff
# break;
# default:
# //do stuff
# }
I was going to mention this but forgot to add it before I hit send.
Best Regards,
~Aaron
On Sat, Mar 22, 2008 at 11:43 PM, Aaron Miller <
[EMAIL PROTECTED]> wrote:
> Polymorphisms is a run time technique. There is no way to determine a
> dynamic class instance's interface at runtime. I would use a switch
> statement in your AnalyzerBundle class to determine which interface an
> analyzer implements and process accordingly, throwing an error on default if
> necessary (realistically, you shouldn't have an unexpected interface). To
> add new analyzer/interfaces, you would just have to add an item to the
> switch statement and an appropriate method or class to handle it. Warning:
> make sure to check extended interfaces in bottom up order.
>
> I'm not sure if this is a generally excepted "design pattern", but it's
> what I would do in this case.
>
> Hope this helps,
>
> ~Aaron
>
>
> On Sat, Mar 22, 2008 at 1:55 PM, Jeroen Beckers <[EMAIL PROTECTED]>
> wrote:
>
> > Hi list!
> >
> > Situation: I have a class that analyzes stuff. There are different
> > analyzing classes, suck as "HeightAnalyzer", "WeightAnalyzer",
> > "LevelAnalyzer", etc. You can add an analyzer to the class by using '
> > myClass.addAnalyzer(newAnalyzer:IAnalyzer)'. As you can see, there is an
> > IAnalyzer interface which all Analyzer's implement. Every time you add an
> > analyzer, it is added to the list using the Decorator pattern. (Every
> > analyzer must analyze a list and pass it to the next analyzing test)
> >
> > Now, the analyzer's analyze certain items. Every analyzer requires a
> > different set of methodes. The HeightAnalyzer requires a getHeight(), the
> > LevelAnaylzer requires a getLevel(), etc. I want to have a different
> > interface for each analyzer, so that I can easily add analyzers
> > (+interfaces).
> >
> > If I want to analyze a list of items, those items must implement the
> > correct interface, according to which analyzers you have added to the class.
> > Fe:
> >
> > var myClass:AnalyzerBundle = new AnalyzerBundle();
> > myClass.addAnalyzer(new HeightAnalyzer());
> > myClass.addAnalyzer(new LevelAnalyzer());
> > myClass.analyze(new Array(item1, item2, item3));
> >
> > What I am looking for now, is a way to make sure that item1, item2 and
> > item3 all implement the IHeightItem and ILevelItem interfaces.
> >
> > I've found a couple of ways to do this, but none of them seemed really
> > good to me. One of them was to have every Analyzer keep track of the
> > interface associated with it, and check if they implement the correct
> > interface, once the analyzer is called. But this would give ugly runtime
> > errors...
> > I'm pretty sure that it can't be done at compile time, but if anyone
> > happens to know some way (hack), or a better way for the runtime errors,
> > please tell me :-). All ideas are welcome
> >
> > Ps: I've just made up all these names, my question is about the
> > technique to be used, not about the project :)
> >
> >
> >
>
>
>
> --
> Aaron Miller
> Chief Technology Officer
> Open Base Interactive, LLC.
> [EMAIL PROTECTED]
> http://www.openbaseinteractive.com
--
Aaron Miller
Chief Technology Officer
Open Base Interactive, LLC.
[EMAIL PROTECTED]
http://www.openbaseinteractive.com
