Document structure is a bit simplified with respect to LATEX, since
documents consist of only two parts.
The preamble starts as soon as HEVEA starts to operate and
ends with the \begin{document} construct.
Then, any input occurring before
\end{document} is translated to html.
However, the preamble is processed
and the preamble comprises the content of the files given as command-line
arguments to HEVEA, see section C.1.1.1).
As a consequence, command and environment definitions that
occur before \begin{document} are performed.
and they remain
valid during all the processing.
In particular one can define a header and a footer, by using the
\htmlhead and \htmlfoot commands in the preamble.
Those commands register their argument as the header and the footer of
the final html document. The header appears first while the footer
appears last in (visible) html output.
This is mostly useful when HEVEA output is later cut into pieces by
HACHA, since both header and footer are replicated
at the start and end of any file generated by HACHA.
For instance, to append a copyright notice at the end of all the html
pages, it suffices to invoke the \htmlfoot command as follows
in the document preamble:
\htmlfoot{\copyright to me}
The \htmlhead command cannot be used for changing anything outside of
the html document body, there are specific commands for doing this.
Those command must be used in the document preamble.
One can
change HEVEA default (empty) attribute of
the opening <body ...> tag by redefining
\@bodyargs.
For instance, you get black text on a white background, when the
following declaration occurs before \begin{document}:
\renewcommand{\@bodyargs}{style="color:black;background:white"}
Since version 1.08, a recommended alternative is to use style sheets:
\newstyle{body}{color:black; background:white;}
One can also change the default (empty) attribute of the opening
<html ...> tag by redefining
\@htmlargs. For instance you can set the language attribute
of the whole document by issuing the following redefinition in
the document preamble:
\renewcommand{\@htmlargs}{lang=en}
Similarly, some elements can be inserted into the output file
head element by redefining the \@meta command
(Such elements typically are meta, link, etc.).
As such text is pure html, it should be included in a
rawhtml environment. For instance, you can specify
author information as follows:
\let\oldmeta=\@meta
\renewcommand{\@meta}{%
\oldmeta
\begin{rawhtml}
<meta name="Author" content="Luc Maranget">
\end{rawhtml}}
Note how \@meta is first bound to
\oldmeta before being redefined and how \oldmeta is
invoked in the new definition of \@meta.
Namely, simply overriding the old definition of \@meta would
imply not outputting default meta-information.
The \@charset command holds the value of the (html) document character
set. By default, this value is US-ASCII.
In previous versions of HEVEA, one could change the
value of the document character set by simply redefining
\@charset. Then, it was users responsability to provide a
(LATEX) document in the correspounding encoding.
This is no longer so, and users should not redefine
\@charset directly. Please, see Section 8.6 for details.