Question

I’m not yet that into design patterns so “Sorry!” to bother you with such a question, that might be obvious.

The thing is, I have several classes: Show, Segment, Command. These three classes are totally different, except the one thing: They all have an NSArray called schedules, which contains ScheduleItem classes.

In my workflow I need to check, if the current time matches a scheduleItem to set the Show,Segment or Command active. So, I’d like to have a method on all these three classes called isActive(). Since this method does the same for all current and future classes, I’m looking for a way to implement the isActive method just once, and reuse it in those classes.

Is there a nice way doing this?

To remember, those classes have absolutely nothing in common, except the schedules array. So, I’d like to avoid subclassing. But you can convince me otherwise.

Answer 1

You can create smth like this

@interface ScheduleCollection : NSObject {
    NSArray* schedules;
}

@property NSArray* schedules;

/**
  Return true if matches.
*/
-(BOOL) match:(ScheduleSclass); //or call it isActive or whatever you like 

@end

Then replace schedules array in Show, Segment, Command with ivar of this class. If you need to compare time just get the property and call match:

Show* show = ...;

BOOL m = [show.schedules match: my_time];