xml-dev - Re: Empty element tags in expat

[Steven Rowe <sarowe@textwise.com>]

Jan- Arve Sæther wrote:
> 
> I'm just wondering if expat can preserve empty elements?
> 
> I'm telling expat to parse this little document fragment:
> <?xml version="1.0"?>
> <size height="180" width="70"/>
> 
> It seems that expat will parse it with no complaints
> and output it to my handlers as "size" is stored as a
> start/end-element pair.
> 
> The consequence is that my output document will look like this:
> <?xml version="1.0"?>
> <size height="180" width="70"></size>
> 
[snip]
> 
> This also seems to be the case for SAX, so I am wondering if there
> is any good reason why it is like this. Simplicity?

The two forms are exactly equivalent.  This is not a parsing problem,
but rather a serialization problem.

In order to support what you want, an event-based parser (Expat, SAX)
would need to: a) read ahead to see whether an element is empty; and
b) emit a different type of event (start-empty-element? or
empty-element (since no start/end)?) from that of the standard
start-element event.  

So I rather suspect that you are correct in assuming that the issue is
simplicity.

Steve Rowe
MNIS-TextWise Labs

***************************************************************************
This is xml-dev, the mailing list for XML developers.
To unsubscribe, mailto:majordomo@xml.org&BODY=unsubscribe%20xml-dev
List archives are available at http://xml.org/archives/xml-dev/
***************************************************************************