Re: XML and stateless protocols

[Miles Sabin <miles@xxxxxxxxxxxxxx>]

Hollenbeck, Scott wrote,
> Mark Baker wrote,
> > XML 1.0 provides external entities, which are an easy way to make
> > the meaning of message depend on something external.  Using
> > schema languages that change the Infoset, like XML Schema, are
> > another way.
> >
> > I think it would be a good idea to discuss this in the draft.
>
> How is this unique to XML, and thus of specific concern for the
> draft?  One could take the general statement of "care must be taken
> not to make the meaning of a message depend on information outside
> the message itself" and apply it to _any_ protocol design.

This is true, but it might be worth emphasizing, because XML provides 
intrinsic mechanisms which allow a document instance to depend on non-
local information.

Not only that, those mechanisms might be abused in unexpected ways 
(particularly if generic off-the-shelf XML parsers are used).

I mentioned a few cases a week or so ago on xml-dev,

  http://lists.xml.org/archives/xml-dev/200206/msg00240.html
  http://lists.xml.org/archives/xml-dev/200206/msg00247.html

Cheers,


Miles