lisp/mail/rfc2368.el

   1 ;;; rfc2368.el --- support for rfc2368
   2
   3 ;; Copyright (C) 1998, 2000-2015 Free Software Foundation, Inc.
   4
   5 ;; Author: Sen Nagata <sen@eccosys.com>
   6 ;; Keywords: mail
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24 ;;
  25 ;; notes:
  26 ;;
  27 ;;   -repeat after me: "the colon is not part of the header name..."
  28 ;;   -if w3 becomes part of emacs, then it may make sense to have this
  29 ;;    file depend on w3 -- the maintainer of w3 says merging w/ Emacs
  30 ;;    is planned!
  31 ;;
  32 ;; historical note:
  33 ;;
  34 ;;   this is intended as a replacement for mailto.el
  35 ;;
  36 ;; acknowledgments:
  37 ;;
  38 ;;   the functions that deal w/ unhexifying in this file were basically
  39 ;; taken from w3 -- i hope to replace them w/ something else soon OR
  40 ;; perhaps if w3 becomes a part of emacs soon, use the functions from w3.
  41
  42 ;;; History:
  43 ;;
  44 ;; 0.3:
  45 ;;
  46 ;;  added the constant rfc2368-version
  47 ;;  implemented first potential fix for a bug in rfc2368-mailto-regexp
  48 ;;  implemented first potential fix for a bug in rfc2368-parse-mailto
  49 ;;  (both bugs reported by Kenichi OKADA)
  50 ;;
  51 ;; 0.2:
  52 ;;
  53 ;;  started to use checkdoc
  54 ;;
  55 ;; 0.1:
  56 ;;
  57 ;;  initial implementation
  58
  59 ;;; Code:
  60
  61 ;; only an approximation?
  62 ;; see rfc 1738
  63 (defconst rfc2368-mailto-regexp
  64   "^\\(mailto:\\)\\([^?]+\\)*\\(\\?\\(.*\\)\\)*"
  65   "Regular expression to match and aid in parsing a mailto url.")
  66
  67 ;; describes 'mailto:'
  68 (defconst rfc2368-mailto-scheme-index 1
  69   "Describes the 'mailto:' portion of the url.")
  70 ;; i'm going to call this part the 'prequery'
  71 (defconst rfc2368-mailto-prequery-index 2
  72   "Describes the portion of the url between 'mailto:' and '?'.")
  73 ;; i'm going to call this part the 'query'
  74 (defconst rfc2368-mailto-query-index 4
  75   "Describes the portion of the url after '?'.")
  76
  77 (defun rfc2368-unhexify-string (string)
  78   "Unhexify STRING -- e.g. 'hello%20there' -> 'hello there'."
  79   (replace-regexp-in-string "%[[:xdigit:]]\\{2\\}"
  80                             (lambda (match)
  81                               (string (string-to-number (substring match 1)
  82                                                         16)))
  83                             string t t))
  84
  85 (defun rfc2368-parse-mailto-url (mailto-url)
  86   "Parse MAILTO-URL, and return an alist of header-name, header-value pairs.
  87 MAILTO-URL should be a RFC 2368 (mailto) compliant url.  A cons cell w/ a
  88 key of 'Body' is a special case and is considered a header for this purpose.
  89 The returned alist is intended for use w/ the `compose-mail' interface.
  90 Note: make sure MAILTO-URL has been 'unhtmlized' (e.g. &amp; -> &), before
  91 calling this function."
  92   (let ((case-fold-search t)
  93         prequery query headers-alist)
  94     (setq mailto-url (replace-regexp-in-string "\n" " " mailto-url))
  95     (if (string-match rfc2368-mailto-regexp mailto-url)
  96         (progn
  97           (setq prequery
  98                 (match-string rfc2368-mailto-prequery-index mailto-url))
  99           (setq query
 100                 (match-string rfc2368-mailto-query-index mailto-url))
 101
 102           ;; build alist of header name-value pairs
 103           (if (not (null query))
 104               (setq headers-alist
 105                     (mapcar
 106                      (lambda (x)
 107                        (let* ((temp-list (split-string x "="))
 108                               (header-name (car temp-list))
 109                               (header-value (cadr temp-list)))
 110                          ;; return ("Header-Name" . "header-value")
 111                          (cons
 112                           (capitalize (rfc2368-unhexify-string header-name))
 113                           (rfc2368-unhexify-string header-value))))
 114                      (split-string query "&"))))
 115
 116           ;; deal w/ multiple 'To' recipients
 117           (if prequery
 118               (progn
 119                 (setq prequery (rfc2368-unhexify-string prequery))
 120                 (if (assoc "To" headers-alist)
 121                     (let* ((our-cons-cell
 122                             (assoc "To" headers-alist))
 123                            (our-cdr
 124                             (cdr our-cons-cell)))
 125                       (setcdr our-cons-cell (concat prequery ", " our-cdr)))
 126                   (setq headers-alist
 127                         (cons (cons "To" prequery) headers-alist)))))
 128
 129           headers-alist)
 130
 131       (error "Failed to match a mailto: url"))))
 132
 133 (provide 'rfc2368)
 134
 135 ;;; rfc2368.el ends here