[Kst] QTextStream to QDomElement

George Staikos staikos at kde.org
Fri Jan 14 19:15:49 CET 2005

On Friday 14 January 2005 12:56, Andrew Walker wrote:
> The first may be true. Have you actually measured this for the
> kind of files we are saving? The second point I disagree with.
> We should not have to be worrying about indentation,
> endl, closing tags, delimiters, etc that QTextStream compels
> us to. I'll reserve judgment on your third point.

   QDom is known to be very slow. 
I also saw some slides about this at a talk.

   We are definitely dealing with big DOM documents too.  The ones in Paris 
were around 300kb (just the XML!!), and Nicolas uses .kst files even bigger 
than that.

    There are future cases where we will also need to extract fragments of the 
DOM as text, so we will be even more wasteful there, creating a complicated 
heavyweight structure only to convert back to text, and then back to DOM 

    Finally, write out an example both ways and you'll see that it's much more 
tedious to write with QDom.  The indentation stuff is not necessary, but it 
was very easy to sneak in and makes it easier to deal with those files for 

   QDom is certainly more elegant than QTextStream, but it's not "ready" yet.

   Note: QDom4 will be much faster than libxml even, apparently, so it might 
change things a bit.  That's probably 1.5-2 years into Kst's future though.

George Staikos
KDE Developer				http://www.kde.org/
Staikos Computing Services Inc.		http://www.staikos.net/

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