Jeffrey W. Baker wrote:
> On Wed, 24 May 2000, Peter Haworth wrote:
> > Jeffrey W. Baker wrote:
> > > myInput = hfTextInputNew();
> > > myInput->addAttr(myInput, "name", "first_name");
> > > myInput->addAttr(myInput, "value", "Jeffrey");
> > > printf("%s\n", myInput->render(myInput));
> > > myInput->destroy(myInput);
> > >
> > > I would expect a similar interface with more methods for a select box,
> > > e.g. mySelect->addOption(mySelect, myOption), and myOption->select.
Is this C or C++? If C, do you have a member for each function in the struct,
and if it's C++, why are you passing myInput twice? Or maybe you just got
carried away with your example.
> > Where do you store those attributes before you do the rendering? If you
> > tie yourself to Apache, you could use tables. If you tie yourself to perl,
> > you can use hashes. Otherwise you have to do your own hashes. Blech,
> > especially if you then use the library with Apache and/or perl - wasted
> > effort.
>
> Actually, there is another way, and that is to simply build a linked list
> of attributes. It doesn't matter what order you put the attributes in, so
> I just add them to the head of the list for performance. Adding to the
> head of a list is faster than hashing anyway. If you use the
> setAttr(self *, char *, char *) method, the list has to be scanned, but is
> is likely to be so short as to not matter.
OK, that seems sensible. There's no reason to go overboard to get more
hash-like semantics, when you'll generally just be stuffing things in, then
reading them all out.
> The other advantage here is storage space. An attribute in this
> implementation takes up only 4*sizeof(void *) + strlen(name) +
> strlen(value) + 2.
Is it a doubly linked list, or are you storing something other than name,
value, next?
> > Bear in mind that it's nice to be able to support arbitrary attributes for
> > things like onMouseClick and the like, horrible though they are. This
> > means that you can't just define structs with members dedicated to
> > specific attributes.
>
> Done. The same approach is also used for adding options to a select box,
> although a select box will have an additional sort() method.
Well, personally, I'd have sorted my options before setting them up. Otherwise
you need unnecessarily complicated comparison functions to keep your "Please
select something" option at the top. ALthough, if it works that way, adding
options to a select has to add to the tail of the list, or you'd have to add
your options in reverse order.
--
Peter Haworth [EMAIL PROTECTED]
"Well, let's just say, 'if your VCR is still blinking 12:00, you don't
want Linux'". --Bruce Perens, Debian's Fearless Leader
