Using htlatex with tikz-dependency

Question

I am trying to generate an html file from a tex file using htlatex. The htlatex works well with simple tikz pictures, but it has problem with the pictures (trees) drawn with tikz-dependency package. Here is my code copied from tikz-dependency manual.

\documentclass{article}
\def\pgfsysdriver{pgfsys-tex4ht.def}

\usepackage{tikz,graphicx,tikz-dependency}
%\usetikzlibrary{external}
\begin{document}
\begin{dependency}
\begin{deptext}[column sep=.5cm, row sep=.1ex]
PRP\$ \& NN \& RB \&[.5cm] VBZ \& VBG \& NN \\
My \& dog \& also \& likes \& eating \& sausage \\
\end{deptext}
\deproot{4}{root}
\depedge{2}{1}{poss}
\depedge{4}{2}{nsubj}
\depedge{4}{3}{advmod}
\depedge{4}{5}{xcomp}
\depedge{5}{6}{dobj}
\wordgroup{2}{4}{4}{pred}
\wordgroup{2}{1}{2}{a0}
\wordgroup{2}{5}{6}{a1}
\groupedge[edge below]{pred}{a0}{ARG0}{4ex} % pred -> a0 (ARG0, 4ex)
\groupedge[edge below]{pred}{a1}{ARG1}{6ex} % pred -> a1 (ARG1, 6ex)
\end{dependency}

\begin{dependency}
\begin{deptext}[column sep=0.2cm]
My \&[.5cm] dog \& also \&[.7cm] likes \&[.4cm] eating \& sausage \\
\end{deptext}
\depedge{2}{1}{poss}
\depedge{4}{2}{nsubj}
\depedge{4}{3}{advmod}
\depedge{4}{5}{xcomp}
\depedge{5}{6}{dobj}
\end{dependency}
\end{document}

For second example, I get a nice tree, though without terminal-nodes (words). The first code throws an error in html. htlatex also doesn't work with qtree and xytree packages! Any help is highly appreciated. This thing is really getting on my nerves!

Answer 1

It is known problem that tex4ht pgfsysdriver does have some problems with text nodes. In such cases, it is better to use tikz externalization.

There are some problems you need to solve:

1. dependendency environment doesn't support externalization. You can replace it with tikzpicture in your case
2. there are several ways to convert externalized pictures to svg, I did some tests and it seems best is to use inkscape in the command line mode
3. you need to configure tex4ht to include svg images.

So, you need to modify your file in such way:

\documentclass{article}

\usepackage{tikz,graphicx,tikz-dependency}

\usetikzlibrary{external}
\tikzset{
    tex4ht inc/.style={
        /pgf/images/include external/.code={%
            \includegraphics[]{##1.svg}%
        }

    }
}

\tikzset{
 external/system call/.add={}                                                
      {; inkscape -z -f "\image.pdf" -l "\image.svg" }    
}
\makeatletter
\@ifpackageloaded{tex4ht}{
    \tikzexternalize[mode=only graphics]
}{
    \tikzexternalize
}
\makeatother
\begin{document}
\begin{tikzpicture}
\begin{deptext}[column sep=.5cm, row sep=.1ex]
PRP\$ \& NN \& RB \&[.5cm] VBZ \& VBG \& NN \\
My \& dog \& also \& likes \& eating \& sausage \\
\end{deptext}
\deproot{4}{root}
\depedge{2}{1}{poss}
\depedge{4}{2}{nsubj}
\depedge{4}{3}{advmod}
\depedge{4}{5}{xcomp}
\depedge{5}{6}{dobj}
\wordgroup{2}{4}{4}{pred}
\wordgroup{2}{1}{2}{a0}
\wordgroup{2}{5}{6}{a1}
\groupedge[edge below]{pred}{a0}{ARG0}{4ex} % pred -> a0 (ARG0, 4ex)
\groupedge[edge below]{pred}{a1}{ARG1}{6ex} % pred -> a1 (ARG1, 6ex)
\end{tikzpicture}

\begin{tikzpicture}
\begin{deptext}[column sep=0.2cm]
My \&[.5cm] dog \& also \&[.7cm] likes \&[.4cm] eating \& sausage \\
\end{deptext}
\depedge{2}{1}{poss}
\depedge{4}{2}{nsubj}
\depedge{4}{3}{advmod}
\depedge{4}{5}{xcomp}
\depedge{5}{6}{dobj}
\end{tikzpicture}
\end{document}

There are several changes:

\tikzset{
        tex4ht inc/.style={
            /pgf/images/include external/.code={%
                \includegraphics[]{##1.svg}%
            }

        }
    }

This is a definition of new tikz style, used in tex4ht for svg inclusion.

\tikzset{
 external/system call/.add={}                                                
      {; inkscape -z -f "\image.pdf" -l "\image.svg"
            }    
}

this definition calls inkscape to convert pdf pictures to svg,

\makeatletter
\@ifpackageloaded{tex4ht}{
    \tikzexternalize[mode=only graphics]
}{
    \tikzexternalize
}
\makeatother

and we need to use this code for correct inclusion of images in tex4ht.

Now you can generate pictures with:

pdflatex -shell-escape filename

You also have to create configuration file for tex4ht, like myconfig.cfg

\Preamble{xhtml}
\makeatletter
\Configure{graphics*}  
         {svg}{  
          {\Configure{Needs}{File: \Gin@base.svg}\Needs{}}
          \Picture[\csname a:GraphicsAlt\endcsname]{\csname Gin@base\endcsname.svg \csname a:Gin-dim\endcsname}%  
         }  
\makeatother
\begin{document}
\tikzexternalize[mode=only graphics]  
\tikzset{tex4ht inc}
\EndPreamble

configuration for svg inclusion is provided here.

Now you can compile the document to html with

htlatex filename myconfig

Result:

Answer 2

There are two things wrong with your code:

1. Missing \begin{document}.
2. The command \def\pgfsysdriver{...} should go after \usepackage{tikz,...}, as some of the macros defined in the pgf driver require lower level macros defined by tikz-pgf.

The following code compiles all right for me with pdflatex and htlatex, both with and without externalized graphics:

\documentclass{article}
\usepackage{tikz,graphicx,tikz-dependency}

\def\pgfsysdriver{pgfsys-tex4ht.def}
%\usetikzlibrary{external}

\begin{document}

\begin{dependency}
\begin{deptext}[column sep=.5cm, row sep=.1ex]
PRP\$ \& NN \& RB \&[.5cm] VBZ \& VBG \& NN \\
My \& dog \& also \& likes \& eating \& sausage \\
\end{deptext}
\deproot{4}{root}
\depedge{2}{1}{poss}
\depedge{4}{2}{nsubj}
\depedge{4}{3}{advmod}
\depedge{4}{5}{xcomp}
\depedge{5}{6}{dobj}
\wordgroup{2}{4}{4}{pred}
\wordgroup{2}{1}{2}{a0}
\wordgroup{2}{5}{6}{a1}
\groupedge[edge below]{pred}{a0}{ARG0}{4ex} % pred -> a0 (ARG0, 4ex)
\groupedge[edge below]{pred}{a1}{ARG1}{6ex} % pred -> a1 (ARG1, 6ex)
\end{dependency}

\begin{dependency}
\begin{deptext}[column sep=0.2cm]
My \&[.5cm] dog \& also \&[.7cm] likes \&[.4cm] eating \& sausage \\
\end{deptext}
\depedge{2}{1}{poss}
\depedge{4}{2}{nsubj}
\depedge{4}{3}{advmod}
\depedge{4}{5}{xcomp}
\depedge{5}{6}{dobj}
\end{dependency}
\end{document}

On the other hand, while the pdf renders fine in the html it's only possible to see the textual information of the trees, no edges or other graphical elements.