How do you pass unknown keys as options to a TikZ picture?

Question

I try to write a command that accepts options, using pgfkeys. Unknown keys are collected in a style, that I try to use as global options for a tikzpicture environement. A minimal example would be:

\documentclass{article}
\usepackage{tikz}

\newif\ifsquare

\pgfqkeys{/test}{%
 square/.is if=square,
 square/.default=true,
% collect unknown keys in style 'remainingkeys':
 .unknown/.code={%
  \let\currname\pgfkeyscurrentname%
  \let\currval\pgfkeyscurrentvalue%
  \ifx#1\pgfkeysnovalue%
   \pgfqkeys{/tikz}{remainingkeys/.append style={\currname}}%
  \else%
   \pgfqkeys{/tikz}{remainingkeys/.append style={\currname=\currval}}%
  \fi%
 }%
}

\newcommand\myfigure[1][]{
% initialize:
 \pgfqkeys{/tikz}{remainingkeys/.style={}}
 \pgfqkeys{/test}{square}
% set user keys:
 \pgfqkeys{/test}{#1}
 \begin{tikzpicture}[/tikz/remainingkeys]
  \ifsquare
   \fill (0,0)rectangle(1,1);
  \else
   \fill (0,0)rectangle(1.2,.8);
  \fi
 \end{tikzpicture}
}

\begin{document}

 \myfigure[square,rotate=45]                % rotated 45 degs; ok
 \myfigure[square,fill=red]                 % red; ok
 \myfigure[square,rotate=45,fill=red]       % red, but doesn't rotate
 \myfigure[square=false]                    % not square
 \myfigure[square=false,fill=red,rotate=45] % not square, not red and rotated 90 degs!

\end{document} 

The command \myfigure simply draws a square or rectangle, depending on the value of the 'square'-key. This key is handled correctly. All other options are handled by the .unknown/.code handler and collected into the style 'remainingkeys', which eventually is passed to \begin{tikzpicture}. The first call of \myfigure indeed draws a square, and rotates it, but the third call doesn't! Somehow not all unknown keys are stored in 'remainingkeys'. In the fifth call even the rotation angle isn't right.

I tried a lot of things, but this is the best that I can come up with, at least without producing any TeX-errors. I'm doing something seriously wrong, but what? I'm dead in the water...

Answer 1

You need to expand the \currname and \currval values first. Otherwise you simply storing this macros which definitions will change. Therefore you loose all but the last option, which is repeated several times like seen in the double rotation in your example.

\documentclass{article}
\usepackage{tikz}

\newif\ifsquare

\pgfqkeys{/test}{%
 square/.is if=square,
 square/.default=true,
% collect unknown keys in style 'remainingkeys':
 .unknown/.code={%
  \let\currname\pgfkeyscurrentname%
  \let\currval\pgfkeyscurrentvalue%
  \ifx#1\pgfkeysnovalue%
   \pgfqkeys{/tikz}{remainingkeys/.append style/.expand once={\currname}}%
  \else%
   \pgfqkeys{/tikz}{remainingkeys/.append style/.expand twice={\expandafter\currname\expandafter=\currval}}%
  \fi%
 }%
}

\newcommand\myfigure[1][]{
% initialize:
 \pgfqkeys{/tikz}{remainingkeys/.style={}}
 \pgfqkeys{/test}{square}
% set user keys:
 \pgfqkeys{/test}{#1}
 \begin{tikzpicture}[/tikz/remainingkeys]
  \ifsquare
   \fill (0,0)rectangle(1,1);
  \else
   \fill (0,0)rectangle(1.2,.8);
  \fi
 \end{tikzpicture}
}

\begin{document}

 \myfigure[square,rotate=45]                % rotated 45 degs; ok
 \myfigure[square,fill=red]                 % red; ok
 \myfigure[square,rotate=45,fill=red]       % red, but doesn't rotate
 \myfigure[square=false]                    % not square
 \myfigure[square=false,fill=red,rotate=45] % not square, not red and rotated 90 degs!

\end{document}