% context --autopdf=auto --schema=2\*4\*2 --numberofpages=16
 %\def\Schema{\doifelsedocumentargument{schema}{\getdocumentargument{schema}}{1*8}}
%\def\Pages{\doifelsedocumentargument{numberofpages}{\getdocumentargument{numberofpages}}{16}}

\setuppapersize[A9,landscape][A7,landscape]

\setupbodyfont[ss,10pt]

\setuplayout[margin=0pt, width=fit, header=2.8ex, footer=2.8ex]
\setupalign[middle,hilo]
\setuppagenumbering [alternative=doublesided,location=footer]
\setupheadertexts[\CONTEXT\ imposition test]

\showframe
\setupbackgrounds [text][text][background=color,backgroundcolor=lightgray]

% Where the block of pages is placed on the sheet
% (relevant if there is space left over.)
\setuplayout [location=middle,marking=on]

\startbuffer[Fakepage]
    \strut
    \blank
    \bold{[\documentvariable{Schema}]}
    \vfill
    This is page \recurselevel
    \vfill
\stopbuffer


\startdocument
   [Schema={\getdocumentargument{schema}}, %{1*8},
	  Nofpages=\doifelsedocumentargument%
	   {numberofpages}{\getdocumentargument{numberofpages}}{1}]
	
\setuparranging[\documentvariable{Schema}]	
	
	% Contents of Documentvariable "Schema" = \documentvariable{Schema}
	
  \dorecurse{\documentvariable{Nofpages}}{\getbuffer[Fakepage]\page}
\stopdocument
