How to display the chapter number in the headers in ConTeXt?

Question

I am using serupheadertexts to define the headers in my document:

\setuphead[chapter]                     [number=yes]

\setupheadertexts[{\getmarking[chapter]}][][][]

I want to access the chapter number, but it is not displaying.

I tried this:

\setupheadertexts[{\getnumber[chapter] \getmarking[chapter]}][][][]

It does not display any number there.

How can I display the chapter number in the headers in ConTeXt?

Answer 1

You can access the first, present, and final values of section counters for the currently active structure component by their name using the command \somenamedheadnumber.

\somenamedheadnumber takes two mandatory arguments:

1. the name of a structure element, e.~g. section, chapter, and
2. one of the identifiers first, current, last that determine the value to be retrieved.

Examples:

%% the initial value of the chapter counter
\somenamedheadnumber{chapter}{first}

%% the number of the final section in the current chapter
\somenamedheadnumber{section}{last}

%% the number of the currently active subsubsection;
%% in the page header this will retrieve the number of the
%% structural last active on the current page
\somenamedheadnumber{subsubsection}{current}

As a shorthand, \namedheadnumber{<name>} is equivalent to \somenamedheadnumber{<name>}{current}.

A more extensive example showing the various getters for structure counters in action:

\setuppagenumbering [location=footer,alternative=doublesided]

\startsetups header.outer
  Chapter
  \space
  \namedheadnumber{chapter}
  \space of \space
  \somenamedheadnumber{chapter}{last}
  \space --- \space
  {\cap\getmarking[chapter]}
\stopsetups

\startsetups header.inner
  Section
  \space
  \namedheadnumber{section}
  \space of \space
  \somenamedheadnumber{section}{last}
  \space --- \space
  {\italic\getmarking[section]}
\stopsetups

\setupheadertexts
  [\setups{header.outer}]
  [\setups{header.inner}]

\starttext
  \getrandomnumber\i25
  \completecontent\page
  \dorecurse{\i}{
    \getrandomnumber\j27
    \startchapter[title=foo]
      \input knuth
      \dorecurse{\j}{
        \startsection[title=bar]
          \input ward\par\input dawkins
        \stopsection
      }
    \stopchapter
  }
\stoptext

Answer 2

The normal way to get the chapter number in the headers is to use \getmarking[chapternumber].

\setupheadertexts[{\getmarking[chapternumber]--\getmarking[chapter]}]

\starttext

\startchapter[title={First chapter}, marking={Mark for first chapter}]
  \input knuth
\stopchapter

\startchapter[title={Second chapter}, marking={Mark for second chapter}]
  \input knuth
\stopchapter

\stoptext

which gives