W3C home > Mailing lists > Public > w3c-sgml-wg@w3.org > October 1996

Re: A17: keep or drop entities?

From: Bill Smith <bill.smith@Eng.Sun.COM>
Date: Tue, 8 Oct 1996 13:22:23 -0700 (PDT)
To: w3c-sgml-wg@w3.org
Message-ID: <libSDtMail.9610081322.24675.bsmith@providence>
Lauren Wood wrote:

> I disagree. I think even the first version of XML should support entities,
> including external text entities. If we want people to support XML (other than
> the we-already-use-SGML crowd), we need to give them something that doesn't
> exist in HTML, and entities are an important part of this. 

XML gives structure and tag extensibility. From my vantage point, this is such a 
huge increment over HTML that everything else is noise. External text entities 
add complexity where it isn't required.

> Any given user agent, whether for HTML or XML, must know whether the
> object/file that is referenced in a document is to be shown inline, or not
> shown. In the case of HTML, that is accomplished by having defined names for
> elements. Thus an HTML UA knows that the SRC attribute on IMG points to a file
> whose contents are to be shown inline, but the HREF attribute on A points to a
> file whose contents are not to be shown. Instead, the contents of the A 
> (which typically don't contain a file name or object reference of any sort) 
> to be highlighted in some way. How is your typical XML UA to know what to do?
> The information will have to be passed in some way. The standard &chap1; or
> &leftarrow; tells an SGML UA to show the contents of the entity. 

Stylesheets tell UAs how to interpret (display) content. They might also be used 
to construct complete UIs given structure and tag extensibility.

> How would the URL method cope with only inserting one paragraph out of a list
> of paragraphs (or a database, for that matter)? We would have to come up with
> an extension to the URL syntax to do so. One of the beauties of using external
> entities is to have one document that contains all the boilerplate texts I 
> for all my documents, and just change the name of the entity in the document
> shown to get the appropriate boilerplate text showing up. This to me is a
> reason for people to use XML. Some of the other reasons are rather nebulous to
> the HTML users. And they are a large proportion of our potential XML users. If
> we don't give these users enough first time around, they're not going to 
> waiting for the second attempt.

I don't disagree with this other than on complexity and therefor timing. 
Including external text entities in XML 1.0 could slow down development of the 
standard and will make XML UA development more difficult (translates into time). 

ime). We are dealing with Web time not ISO time.
Received on Tuesday, 8 October 1996 16:24:35 UTC

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