Show current section or chapter in header in ConTeXt

Question

I've found this command:

\setupheadertexts[][{\getmarking[sectionnumber]\ \getmarking[section]}]

to show the current section in the header. But how can I show either the current chapter or the current section in the header depending on the fact the current page already belongs to a section or not?

Answer 1

I do not know an elegant solution, but this works ok (thanks to the wiki at contextgarden):

\startsetups testheader
\expanded{\doifsomethingelse{\fetchmark[section][first]}}
  {\getmarking[sectionnumber]\ \getmarking[section]}
  {\getmarking[chapternumber]\ \getmarking[chapter]}
\stopsetups

\setupheadertexts[][\setups{testheader}]