By accident I found something that seems to work.
With \xmlregistereddocumentsetups{#1}{#1} put before the \xmlflush{#1} ConTeXt processing resumes on the node.
What I do not understand however, is why \xmlcontext does not work in general.
Is it possible to have the \xmlregistereddocumentsetups action put in somewhere or in such a way that \xmlflush and friends always succeed? I did not understand enough of the code to fully grasp what is is is not happening.

On 9 mei 2012, at 14:53, Meer, H. van der wrote:

Loaded xml with: xmlinclude{problem}{include}{file}

Then called up parts of its contents through a setup:
\startxmlsetups xam:define:get
% The definition is the one with content.
\xmldoiftext{#1}{.}{
  \foundtrue
  \xmlflush{#1}
  \xmlcontext{#1}{.}
}
\stopxmlsetups

The strange thing is that the \xmlflush typesets verbatim the contents of the node called up:

<math version="2.0" xmlns="http://www.w3c.org/mathml"> <apply> <eq/> <ci> f(x) </ci> <apply> <plus/> <ci> 1 </ci> <apply> <power/> <ci> x </ci> <ci> 4 </ci> </apply> <apply> <power/> <ci> x </ci> <ci> 7 </ci> </apply> </apply> </apply> </math>

but, to my surprise the \xmlcontext{#1}{.} lets it disappear completely. So does \xmlflushcontext{#1}. In other parts of the program \xmlcontext does what it should do, thus the mkvi format seems ok.

What could have happened? Some detrimental effect of the \xmlinclude?

Hans van der Meer