[NTG-context] XML: flush to lua function

Hi, I have the following xml setup with a lua function: \startluacode function markingLength(s) _,n = s:gsub("%S+","") if n > 3 then context("yes" .. " ...") else context("no") end end \stopluacode \startxmlsetups xml:ink:ink-title:marking %\ctxlua{markingLength(\xmlflush{#1})} % does not work \ctxlua{markingLength{"1 2 3 4"}} \stopxmlsetups While the function works, I cannot use xmlflush here. How can I properly pass the xml content to the lua function? Best, Denis