[thelist] xml is good for...?

[Luther, Ron]

Jeremy asked:


>I'm planning out a new cook/recipe website 

Hi Jeremy!

Neat.  Sounds like fun.  Lots of good examples out there.


> * exactly what advantage would implementing XML offer me?
> * and where, in the site/database/etc. would I implement it?

Good questions!

So far everyone seems to be taking the party line.  I kinda like XML.  I think it is a very flexible format.  But I'm gonna take a 'counterpoint' position here anyway and maybe stir things up.  ;-)

Do you *need* XML for a small personal recipe site?  Are there lots of feeds of XML recipes you can pull in - that grant you rights to republish - on your site?  Are there a handful of 'recipe concentrator' sites out there anxious to pull in casserole recipes from a world-wide network of XML outbounds?  If not, then you probably don't really *need* XML.  


Yeah, XML is supposed to be neat for presenting different views of the data.  'Some day' you may be able to bring up the same XML file in different apps and have it appear 'differently'.  (Whatever the heck that means.  I mean, really, the data is the data.  The data doesn't "morph" and become something else just because it's being read by a different app.  Is your "1/4 cup" measurement going to magically change to metric if the file is being read in Europe?) That would be kinda cool.  But I'm not really seeing that happen today.  Are there examples?


Yeah, XML lets you interact with numerous sources.  However, to me it doesn't seem much different from any other situation where folks have built different applications around a 'common' and well-defined data interchange format.  Electronic Fund Transfers existed in the banking world prior to XML.  Freight carrier '856 signals' were letting customers know packages have been delivered prior to XML.  Purchase orders have been placed against parts manufacturers in the automotive industry in a standardized format prior to XML.  

Sorry, XML doesn't seem like magic to me.


It also doesn't mean you still can't run into problems.  Here are a couple I have already run into with XML, (in a different context naturally):

* Pulled in some nice recipes from Europe and Latin America did you?  I hope your app handles non ASCII-7 characters ... or it's likely to self-destruct on you.

* Malformed data still exists in the XML world.  An app built to handle hundreds of thousands of 25kb to 125kb XML files can still choke and die when it hits that 6Mb monster file.

* "Fancy" conditional rules can be built into XML designs.  "Hey! Your outbound showed a 'temp' value of 400 in the 'oven' block. My soufflé burned!  What gives?" --- "Oh!  You didn't pick up the 'oven-type' value of "pre-heat".  When the 'oven' block contains a pre-heat you have to use the 'temp' value from the 'oven2' block for the actual cooking."  Conditional rules in the data structure can be kind of a pain to work with.


Anyway - have fun!

RonL.