XML in the real world... Was "Re: Another look at namespaces"

Tyler Baker tyler at infinet.com
Fri Sep 17 06:22:47 BST 1999

Terje Norderhaug wrote:

> At 1:01 PM 9/16/99, Tyler Baker wrote:
> >
> >True, but I think all of this misses the point here. Since November 1997
> >when I started
> >working with XML, I have never once found any need for a DTD or some other
> >Schema language for
> >the applications I have written which use XML. For databases, schema's I
> >feel are very
> >necessary, but I just have not found any real-world use for DTD's or
> >schemas to date other
> >than as a technical document a programmer can refer to.
> An XML editor can facilitate authoring much better if it has a DTD
> available. With a DTD, the editor can provide a sophisticated user
> interface that suggests the elements that can be used, where they can be
> used, and their attributes. Without a DTD, the author will be required to
> specify the names of each element and attribute, making authoring
> cumbersome. So DTDs have real world use even if the document can be
> processed without.

XML is used as a base for all sorts of document and data formats. An editor
which simply displays a tree diagram of XML content does not buy you much. HTML
editors used to do this and still do cause some people do like to do things by
hand, but really most HTML editors are WYSIWYG in nature now. XML content is
generally and almost exclusively created by a script or software that uses XML
as either a document format or else as a serialization protocol for some type
of object. In both instances, the software almost always writes out elements
directly to a stream.

The point is, if you want to do redundant validation at the parser level and
then at the application level, then you are always free to do so. Either way,
until we have machines that actually think you are not gonna be able to just
take some abstract piece of content that does not have a particular software
module associated with it and do anything interesting with it. Most
high-performance HTML parsers I am aware of just parse the data directly into
an object tree and enforce the rules of HTML directly rather than fallback on a

So again what do 3 namespaces buy you that one namespace does not even if you
have 3 different DTD's for XHTML?


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