[xml] newbie questions about xmlwriter

[Dave Nomura <dcnltc us ibm com>]

I am trying to decide whether or not I can use xmlwriter instead of the 
ad hoc routines that I had written for generating XML.  My understanding 
of what is in the xmlwriter API is pretty much limited to the routines 
used in testwriter.c.  I found that searching the alphabetic index was 
not very useful since it contains tons of stuff other than xmlwriter.

1. Is there a better way of familiarizing myself with the capabilities 
of the xmlwriter portion of libxml2?  documentation specific to xmlwriter?

2. I couldn't find any routine that would use the abbreviated method of 
closing an element that does not contain any data: for example, <element 
attr="abc" \>

3. In my application the place where the information used to generate 
some of the XML happens before the code that actually creates the XML 
file.  In my ad hoc routines I simply built up the XML string and saved 
it until later on during the XML generation process.  Is there any way 
in the libxml2/xmlwriter interface for buffering a chunk of XML to be 
output somewhere in the middle of some other XML generation? I noticed 
some sort of buffered
XML generation in testwriter.c but it seemed to involve creating a 
different writer.  I couldn't see how you could combine this with 
unbuffered XML generation.

4. The xmlwriter routines in testwriter.c all involve opening a writer 
associated with a file.  Are there other interfaces that write the XML 
to standard output?  to a string?