Will, I used the second model (originally about 20 years ago) with the initial empty value. Neither model is really very simple, but with the second model we created one or two I-descriptor subroutines that can allow dictionaries to be tailored to any tag you want to look for and select for all values associated with that tag quite nicely. Display routines are also not too daunting.
There are certainly worse file structures to deal with than the second model. But maybe I'm biased, I 'invented' its use at a previous company, and I and the rest of the company worked with it for at least 15 years. Best Regards, Richard Lewis On Thu, Dec 9, 2010 at 3:09 PM, <fft2...@aol.com> wrote: > Years ago I had written a system, far predating XML, where the element-tags > were unpredictable. Essentially the user was allowed to create any tags > they wished, and any number of tags they wished, attached to another item. > > Each tag had an associated value. So far example > Zip Code = 95062 > > You could not however predict what tags a person would use, they were all > free-form and user-supplied, but you still had to store the tag with their > associated value. > > At the time I developed two ideas for how to do this in a Pick item > > TAGS1052 > 001 Make = Chrysler > 002 Model = LeBaron > 003 Age = 7 years and 3 days > > TAGS1052 > 001 Make]Model]Age > 002 Chrysler > 003 LeBaron > 004 7 years and 3 days > > The first model is clear. Anyone with no programming background at all, > can easily understand it, and also easily edit it. It suffers from > requiring > more elaborate programming than the second model, as you have to parse > every > element. > > The second model is not quite as clear. You determine the attibute > position of the "value" by locate the tag in attribute 1 and then adding 1 > to it. > That gives you the attribute number where the value lives. Alternately you > could simply pre-fill attribute 1 with an initial null to push everything > forward 1 place, then you wouldn't have to add 1 after your locate. > > Comments? Critiques? Nasty cat-calls and grimaces? > > Will Johnson > > > _______________________________________________ > U2-Users mailing list > U2-Users@listserver.u2ug.org > http://listserver.u2ug.org/mailman/listinfo/u2-users > _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
