[Development] Qt XML and Qt Xml Patterns

Bernhard Lindner private at bernhard-lindner.de
Tue May 21 09:15:04 CEST 2019

Hi Thiago!

Thanks a lot for the information!

However, the streaming classes are absolutely no replacement for the DOM classes. In
theory yes, they both read and write XML. In reality they are different to a degree that
it is practically impossible to replace DOM by stream. For legacy code anway. 

Even for new code the stream API is simply to bad to use it. Appart from speed, DOM is far
superiorer for every use case. The resulting code is, compared to the DOM solution,
impractical and maintaining it is a pain.

Unlucky me. Deprecation of these two components literally broke every application I have
ever written using Qt. I hope they will have new maintainers some day.

> > Is it correct that the Qt XML and Qt Xml Patterns components are both
> > deprecated?
> Yes, they are.
> > 
> > If yes, are there any details known like:
> > - How long or up to which Qt version will these components be part of Qt?
> > - Will replacment components be available?
> The replacement for QtXml are the streaming classes in QtCore. They've been 
> available for 10 years.
> There is no replacement for the XMLPatterns module.
> > - Are security fixes still be implemented?
> Yes, definitely, for as long as we ship them plus 5 years.
> > - Are the deprecations irrevocable?
> No. Deprecations are only irrevocable when we want to get rid of code that is 
> in the way of making progress, such as the QList discussion. Those two modules 
> are not in the way of anything else, so the decision can change.
> All it takes is someone stepping up to maintain either or both of them.

Best Regards, 
Bernhard Lindner

More information about the Development mailing list