RE: [libxml++] writing formatted (indented) files

[andy glew amd com]

> Should we elaborate something more sophisticated so the user 
> can choose wether the files has to be formatted of not ? I'm not sure it will 
> be a frequent need, and if it's really the case, xmlKeepBlanksDefault(1) 
> could still be called directly if such a need comes.

I think I need more precise control of indentation
and whitespace significance than this,
and I'm quite happy to roll my own,
but I would appreciate some examples/documentation
as to exactly how to control it.

My biggest concern: I want all whitespace and newlines 
to be preserved on input, as is the XML standard.
This probably should be working,
but I haven't been able to get it.

Exactly what is the usage model?

(I'll be perfectly honest: I can't even tell from the name whether
xmlKeepBlanksDefault(0) or 1 preserves whitespace or not.  And
brief experiments show no effect. Being anglo-Quebecois, I am 
familiar with such Franglais name mapping problems. :-)

E.g. is the value of xmlKeepBlanksDefault sampled and preserved
at the time that an xmlpp::Document is created?

     xmlKeepBlanksDefault(0);
     xmlpp::DomParser parser0;
  

     xmlKeepBlanksDefault(1);
     xmlpp::DomParser parser1;

     parser0.parse_file("foo");  // parsed keeping blanks
     parser1.parse_file("foo");  // parsed not keeping blanks

Or is it sampled only within the parse routine?

     xmlKeepBlanksDefault(0);
     xmlpp::DomParser parser00;
     xmlpp::DomParser parser01;  

     xmlKeepBlanksDefault(1);
     xmlpp::DomParser parser10;
     xmlpp::DomParser parser11;

     xmlKeepBlanksDefault(0);  
     parser00.parse_file("foo");  // parsed keeping blanks
     xmlKeepBlanksDefault(0);  
     parser01.parse_file("foo");  // parsed not keeping blanks

     xmlKeepBlanksDefault(0);  
     parser10.parse_file("foo");  // parsed keeping blanks
     xmlKeepBlanksDefault(0);  
     parser11.parse_file("foo");  // parsed not keeping blanks

... and similarly, possibly, for the print routines.

I.e. is xmlKeepBlanks sampled at object creation time,
or at method invocation time.

Related: is whitespace preservation object oriented, or not?