[texhax] keyval options in the closing part of an environment

[Heiko Oberdiek]

On Sun, Apr 25, 2010 at 10:01:12PM -0300, José Romildo Malaquias wrote:

> I want to define a new environment using an environment from the
> fancyvrb.
> 
> In order to simplify the problem, let's consider the following LaTeX
> document, which demonstrates the original problem:
> 
>   \documentclass[a4paper]{article}
>   \usepackage{graphicx}
> 
>   \newenvironment{env}[1][]
>    {\gdef\temp{#1}
>     \begin{quote}}
>    {\includegraphics[\temp]{/usr/share/pixmaps/xchat.png}
>     \end{quote}}

\newenvironment*{env}[1][]{%
  \def\envparam{#1}%
  \begin{quote}%
}{%
  \expandafter\includegraphics\expandafter
  [\expandafter{\envparam}]{/usr/share/pixmaps/xchat.png}%
  \end{quote}%
}

Package keyval looks for '=' and ','. Therefore these
syntax characters must not be hidden inside a macro.
(The additional curly braces have the purpose to prevent
syntax problems, if #1 contains ']'.)

Another possibility:

\newenvironment*{env}[1][]{%
  \def\envgraphics{%
    \includegraphics[{#1}]{/usr/share/pixmaps/xchat.png}%
  }%
  \begin{quote}%
}{%
  \envgraphics
  \end{quote}%
}
 
Yours sincerely
  Heiko Oberdiek