lisp/ob-mscgen.el

   1 ;;; ob-msc.el --- Babel Functions for Mscgen         -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2010-2018 Free Software Foundation, Inc.
   4
   5 ;; Author: Juan Pechiar
   6 ;; Keywords: literate programming, reproducible research
   7 ;; Homepage: https://orgmode.org
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25 ;;
  26 ;; This software provides EMACS org-babel export support for message
  27 ;; sequence charts.  The mscgen utility is used for processing the
  28 ;; sequence definition, and must therefore be installed in the system.
  29 ;;
  30 ;; Mscgen is available and documented at
  31 ;; http://www.mcternan.me.uk/mscgen/index.html
  32 ;;
  33 ;; This code is directly inspired by Eric Schulte's ob-dot.el
  34 ;;
  35 ;; Example:
  36 ;;
  37 ;; #+begin_src mscgen :file example.png
  38 ;; msc {
  39 ;;  A,B;
  40 ;;  A -> B [ label = "send message" ];
  41 ;;  A <- B [ label = "get answer" ];
  42 ;; }
  43 ;; #+end_src
  44 ;;
  45 ;; Header for alternative file type:
  46 ;;
  47 ;; #+begin_src mscgen :file ex2.svg :filetype svg
  48
  49 ;; This differs from most standard languages in that
  50 ;;
  51 ;; 1) there is no such thing as a "session" in mscgen
  52 ;; 2) we are generally only going to return results of type "file"
  53 ;; 3) we are adding the "file" and "filetype" header arguments
  54 ;; 4) there are no variables
  55
  56 ;;; Code:
  57 (require 'ob)
  58
  59 (defvar org-babel-default-header-args:mscgen
  60   '((:results . "file") (:exports . "results"))
  61   "Default arguments to use when evaluating a mscgen source block.")
  62
  63 (defun org-babel-execute:mscgen (body params)
  64   "Execute a block of Mscgen code with Babel.
  65 This function is called by `org-babel-execute-src-block'.
  66 Default filetype is png.  Modify by setting :filetype parameter to
  67 mscgen supported formats."
  68   (let* ((out-file (or (cdr (assq :file params)) "output.png" ))
  69          (filetype (or (cdr (assq :filetype params)) "png" )))
  70     (unless (cdr (assq :file params))
  71       (error "
  72 ERROR: no output file specified.  Add \":file name.png\" to the src header"))
  73     (org-babel-eval (concat "mscgen -T " filetype " -o " out-file) body)
  74     nil)) ;; signal that output has already been written to file
  75
  76 (defun org-babel-prep-session:mscgen (_session _params)
  77   "Raise an error because Mscgen doesn't support sessions."
  78   (error "Mscgen does not support sessions"))
  79
  80 (provide 'ob-mscgen)
  81
  82
  83
  84 ;;; ob-msc.el ends here