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Re: Damn sisters :-)

On 12/10/01 3:17 PM, "Ondra Cada" <email@hidden> wrote:
>>>>>>> Riccardo Santato (RS) wrote at Mon, 10 Dec 2001 19:11:47 +0100:
> RS> >You are not supposed to have access to another class's data. Create
> RS> >accessor methods to access the data. For instance,
> RS> >- (id)myInstanceVariable
> RS> >{
> RS> >return myInstanceVariable;
> RS> >}
> RS>
> RS> I've already thought about this option but I supposed I was rather stupid
> RS> to use a "dummy" function just to pass a variable... I hoped there was a
> RS> cleaner way :-))
>
> This is actually the very cleanest one, for the excellent reason that you
> are free the next year or so to change the implementation so that this will
> look like, say
>
> - (id)myInstanceVariable {
> return [[myInstanceVariableStorage objectForKey:@"oldInstances]
> objectAtIndex:3];
> }
>
> without breaking backward compatibility the slightest bit. It's one of the
> more powerful and nicest OO things ;)

This is totally unrelated to the topic at hand, but one of the really cool
things about C# (no Microsoft flames, please :P) that I wish Objective-C had
are properties. They let you simulate normal member variables but actually
call accessor and set functions.
For instance, you can have a String myStr property that actually sets
something in a dictionary in its implementation, like in Ondra's example,
transparently. This lets the user do simply:
MyClass.myStr = "Blah"
String myLocalStr = MyClass.myStr;
And both will not set the variable directly but will instead call the
associated get or set function. Pretty neato, if you ask me ;)

Thanks. Brian

References: 
 >Re: Damn sisters :-) (From: Ondra Cada <email@hidden>)



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