Cart
[Home] [By Thread] [By Date] [Recent Entries]
In message <34D1E921.6B73@z...>, Trevor Turton <trevort@z...> writes >Is it legal (and surely it must be) to imbed one element within >another? To take a common example from current HTML practice, to imbed >a <TABLE> element within a <FORM> element so that the graphical layout >of the <FORM> <INPUT> tags can be controlled? > >And if so, how does XML resolve a given tag if it occurs within element >A which is imbedded within element B, and the particular tag happens to >be defined and valid in both element A and element B? Unlikely today >when all HTML elements and tags are controlled by a single standards >body (well, almost). Inevitable in the future as independent >organisations develop and distribute their own DTDs. It's no problem. Because XML is well-formed, and doesn't allow any tags to be omitted, the context of every element is crystal clear. If an XML processor has encountered <A> followed by <B>, then it knows it is inside <B>. If an <X> then comes along, the <X> is 'inside' <B>, which in turn, of course, is 'inside' <A>. The XML processor must subsequently get an </X>, a </B> and an </A> in that order to 'back out' of the hierarchy it has created. This is only an issue in HTML because (a) HTML adopted some fairly sophisticated tag omission rules from SGML; and (b) every HTML parser proceeded to ignore this and treat tags as point markers rather than nodes in a well-defined tree structure. Richard Light. Richard Light SGML/XML and Museum Information Consultancy richard@l... xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
|
