xsl or dtd? (begginers question) 1

[birney29]

Hi,

just started trying to learn XML. I understand about the Syntax of tags ect, but i was wondering, if your using an xslt file to transform your xml, do you need a DTD? if so why?

thanks

Kenny.

 

[MrTom]

the xsl stylesheet doesn't always need the xml file to come with a DTD. in fact, as you can imagine, it slows things down quite a bit. without it tho you can't really trust the xml - so if your xsl file assumes that there is an element <title> in every <book> it won't be able to throw an error if it's not there. but if you had a dtd with the xml it would make sure that every <book> did have a <title> before the xsl started to do anything.

i always set myself the rule that if i'm using a server to process xml (and my own scripts make the xml itself) i don't include the dtd because i can trust my own code - or rather i test my code with DTDs then remove them when it goes live.

if i'm writing xsl for client side processing i always give the DTD to the user, because they might not trust my xml and they probably don't notice the extra cpu time taken by checking the xml.