SAX2: DTDDeclHandler (minimalist position)

uche.ogbuji at uche.ogbuji at
Sat Mar 27 02:39:33 GMT 1999

> > public interface DTDDeclHandler
> > {
> >     public final static int ATTRIBUTE_DEFAULTED = 1;
> >     public final static int ATTRIBUTE_IMPLIED = 2;
> >     public final static int ATTRIBUTE_REQUIRED = 3;
> >     public final static int ATTRIBUTE_FIXED = 4;
> > 
> How committed are you to using integer constants? I know this is common,
> but it tends to lend itself to bad code. Some people prefer a solution
> like this:
> public class AttributStatus {
>   public final static AttributeStatus ATTRIBUTE_DEFAULTED = 
>    new AttributeStatus();
>   public final static AttributeStatus ATTRIBUTE_IMPLIED =
>    new AttributeStatus();
>   public final static AttributeStatus ATTRIBUTE_FIXED =   
>    new AttributeStatus();
>   public final static AttributeStatus ATTRIBUTE_REQUIRED =   
>    new AttributeStatus();
>   private AttributeStatus() {}
> }
> This creates four menmonic constants you want and gives them a checkable
> type.  New constants can't be created because of the private constructor.
> And there's no chance that anybody's going to write code like
>   if (getAttributeStatus() == 1) {
>    doSomething();
>   }
> Programmers are more or less forced to use the constants. What do you
> think?

I personally take a very dim view of systems trying to "force" programmers 
into intrinsically good practices.  Programmers can abuse any system you 
present, and at some point you have to accept that they are adults, and must 
be free to cut off their own noses if they wish.

The good programming practice of replacing "magic numbers" with descriptive 
constants is even older than the structured programming movement, and any 
programmer who writes

if (getAttributeStatus() == 1)


if (getAttributeStatus() == ATTRIBUTE_DEFAULTED )

Fully deserves his own bugs, or roasting at the next code-review.

Furthermore, I've been thinking of proposing that the SAX2 interfaces be 
specified in IDL rather than Java (or at least publishing an IDL translatiuon 
when the interfaces are stabilized), and your proposal wouldn't wash in IDL.

Uche Ogbuji
FourThought LLC, IT Consultants
uche.ogbuji at	(970)481-0805
Software engineering, project management, Intranets and Extranets

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