mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-11 09:20:51 +00:00
515 lines
16 KiB
EmacsLisp
515 lines
16 KiB
EmacsLisp
;;; html2text.el --- a simple html to plain text converter
|
|
|
|
;; Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
|
|
|
|
;; Author: Joakim Hove <hove@phys.ntnu.no>
|
|
|
|
;; This file is part of GNU Emacs.
|
|
|
|
;; GNU Emacs is free software; you can redistribute it and/or modify
|
|
;; it under the terms of the GNU General Public License as published by
|
|
;; the Free Software Foundation; either version 3, or (at your option)
|
|
;; any later version.
|
|
|
|
;; GNU Emacs is distributed in the hope that it will be useful,
|
|
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
;; GNU General Public License for more details.
|
|
|
|
;; You should have received a copy of the GNU General Public License
|
|
;; along with GNU Emacs; see the file COPYING. If not, write to the
|
|
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
|
;; Boston, MA 02110-1301, USA.
|
|
|
|
;;; Commentary:
|
|
|
|
;; These functions provide a simple way to wash/clean html infected
|
|
;; mails. Definitely do not work in all cases, but some improvement
|
|
;; in readability is generally obtained. Formatting is only done in
|
|
;; the buffer, so the next time you enter the article it will be
|
|
;; "re-htmlized".
|
|
;;
|
|
;; The main function is `html2text'.
|
|
|
|
;;; Code:
|
|
|
|
;;
|
|
;; <Global variables>
|
|
;;
|
|
|
|
(eval-when-compile
|
|
(require 'cl))
|
|
|
|
(defvar html2text-format-single-element-list '(("hr" . html2text-clean-hr)))
|
|
|
|
(defvar html2text-replace-list
|
|
'(("´" . "`")
|
|
("&" . "&")
|
|
("'" . "'")
|
|
("¦" . "|")
|
|
("¢" . "c")
|
|
("ˆ" . "^")
|
|
("©" . "(C)")
|
|
("¤" . "(#)")
|
|
("°" . "degree")
|
|
("÷" . "/")
|
|
("€" . "e")
|
|
("½" . "1/2")
|
|
(">" . ">")
|
|
("¿" . "?")
|
|
("«" . "<<")
|
|
("&ldquo" . "\"")
|
|
("‹" . "(")
|
|
("‘" . "`")
|
|
("<" . "<")
|
|
("—" . "--")
|
|
(" " . " ")
|
|
("–" . "-")
|
|
("‰" . "%%")
|
|
("±" . "+-")
|
|
("£" . "£")
|
|
(""" . "\"")
|
|
("»" . ">>")
|
|
("&rdquo" . "\"")
|
|
("®" . "(R)")
|
|
("›" . ")")
|
|
("’" . "'")
|
|
("§" . "§")
|
|
("¹" . "^1")
|
|
("²" . "^2")
|
|
("³" . "^3")
|
|
("˜" . "~"))
|
|
"The map of entity to text.
|
|
|
|
This is an alist were each element is a dotted pair consisting of an
|
|
old string, and a replacement string. This replacement is done by the
|
|
function `html2text-substitute' which basically performs a
|
|
`replace-string' operation for every element in the list. This is
|
|
completely verbatim - without any use of REGEXP.")
|
|
|
|
(defvar html2text-remove-tag-list
|
|
'("html" "body" "p" "img" "dir" "head" "div" "br" "font" "title" "meta")
|
|
"A list of removable tags.
|
|
|
|
This is a list of tags which should be removed, without any
|
|
formatting. Note that tags in the list are presented *without*
|
|
any \"<\" or \">\". All occurrences of a tag appearing in this
|
|
list are removed, irrespective of whether it is a closing or
|
|
opening tag, or if the tag has additional attributes. The
|
|
deletion is done by the function `html2text-remove-tags'.
|
|
|
|
For instance the text:
|
|
|
|
\"Here comes something <font size\"+3\" face=\"Helvetica\"> big </font>.\"
|
|
|
|
will be reduced to:
|
|
|
|
\"Here comes something big.\"
|
|
|
|
If this list contains the element \"font\".")
|
|
|
|
(defvar html2text-format-tag-list
|
|
'(("b" . html2text-clean-bold)
|
|
("strong" . html2text-clean-bold)
|
|
("u" . html2text-clean-underline)
|
|
("i" . html2text-clean-italic)
|
|
("em" . html2text-clean-italic)
|
|
("blockquote" . html2text-clean-blockquote)
|
|
("a" . html2text-clean-anchor)
|
|
("ul" . html2text-clean-ul)
|
|
("ol" . html2text-clean-ol)
|
|
("dl" . html2text-clean-dl)
|
|
("center" . html2text-clean-center))
|
|
"An alist of tags and processing functions.
|
|
|
|
This is an alist where each dotted pair consists of a tag, and then
|
|
the name of a function to be called when this tag is found. The
|
|
function is called with the arguments p1, p2, p3 and p4. These are
|
|
demontrated below:
|
|
|
|
\"<b> This is bold text </b>\"
|
|
^ ^ ^ ^
|
|
| | | |
|
|
p1 p2 p3 p4
|
|
|
|
Then the called function will typically format the text somewhat and
|
|
remove the tags.")
|
|
|
|
(defvar html2text-remove-tag-list2 '("li" "dt" "dd" "meta")
|
|
"Another list of removable tags.
|
|
|
|
This is a list of tags which are removed similarly to the list
|
|
`html2text-remove-tag-list' - but these tags are retained for the
|
|
formatting, and then moved afterward.")
|
|
|
|
;;
|
|
;; </Global variables>
|
|
;;
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;;
|
|
;; <Utility functions>
|
|
;;
|
|
|
|
|
|
(defun html2text-replace-string (from-string to-string min max)
|
|
"Replace FROM-STRING with TO-STRING in region from MIN to MAX."
|
|
(goto-char min)
|
|
(let ((delta (- (string-width to-string) (string-width from-string)))
|
|
(change 0))
|
|
(while (search-forward from-string max t)
|
|
(replace-match to-string)
|
|
(setq change (+ change delta)))
|
|
change))
|
|
|
|
;;
|
|
;; </Utility functions>
|
|
;;
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;;
|
|
;; <Functions related to attributes> i.e. <font size=+3>
|
|
;;
|
|
|
|
(defun html2text-attr-value (list attribute)
|
|
"Get value of ATTRIBUTE from LIST."
|
|
(nth 1 (assoc attribute list)))
|
|
|
|
(defun html2text-get-attr (p1 p2)
|
|
(goto-char p1)
|
|
(re-search-forward " +[^ ]" p2 t)
|
|
(let* ((attr-string (buffer-substring-no-properties (1- (point)) (1- p2)))
|
|
(tmp-list (split-string attr-string))
|
|
(attr-list)
|
|
(counter 0)
|
|
(prev (car tmp-list))
|
|
(this (nth 1 tmp-list))
|
|
(next (nth 2 tmp-list))
|
|
(index 1))
|
|
|
|
(cond
|
|
;; size=3
|
|
((string-match "[^ ]=[^ ]" prev)
|
|
(let ((attr (nth 0 (split-string prev "=")))
|
|
(value (nth 1 (split-string prev "="))))
|
|
(setq attr-list (cons (list attr value) attr-list))))
|
|
;; size= 3
|
|
((string-match "[^ ]=\\'" prev)
|
|
(setq attr-list (cons (list (substring prev 0 -1) this) attr-list))))
|
|
|
|
(while (< index (length tmp-list))
|
|
(cond
|
|
;; size=3
|
|
((string-match "[^ ]=[^ ]" this)
|
|
(let ((attr (nth 0 (split-string this "=")))
|
|
(value (nth 1 (split-string this "="))))
|
|
(setq attr-list (cons (list attr value) attr-list))))
|
|
;; size =3
|
|
((string-match "\\`=[^ ]" this)
|
|
(setq attr-list (cons (list prev (substring this 1)) attr-list)))
|
|
;; size= 3
|
|
((string-match "[^ ]=\\'" this)
|
|
(setq attr-list (cons (list (substring this 0 -1) next) attr-list)))
|
|
;; size = 3
|
|
((string= "=" this)
|
|
(setq attr-list (cons (list prev next) attr-list))))
|
|
(setq index (1+ index))
|
|
(setq prev this)
|
|
(setq this next)
|
|
(setq next (nth (1+ index) tmp-list)))
|
|
;;
|
|
;; Tags with no accompanying "=" i.e. value=nil
|
|
;;
|
|
(setq prev (car tmp-list))
|
|
(setq this (nth 1 tmp-list))
|
|
(setq next (nth 2 tmp-list))
|
|
(setq index 1)
|
|
|
|
(when (and (not (string-match "=" prev))
|
|
(not (string= (substring this 0 1) "=")))
|
|
(setq attr-list (cons (list prev nil) attr-list)))
|
|
(while (< index (1- (length tmp-list)))
|
|
(when (and (not (string-match "=" this))
|
|
(not (or (string= (substring next 0 1) "=")
|
|
(string= (substring prev -1) "="))))
|
|
(setq attr-list (cons (list this nil) attr-list)))
|
|
(setq index (1+ index))
|
|
(setq prev this)
|
|
(setq this next)
|
|
(setq next (nth (1+ index) tmp-list)))
|
|
|
|
(when (and this
|
|
(not (string-match "=" this))
|
|
(not (string= (substring prev -1) "=")))
|
|
(setq attr-list (cons (list this nil) attr-list)))
|
|
;; return - value
|
|
attr-list))
|
|
|
|
;;
|
|
;; </Functions related to attributes>
|
|
;;
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;;
|
|
;; <Functions to be called to format a tag-pair>
|
|
;;
|
|
(defun html2text-clean-list-items (p1 p2 list-type)
|
|
(goto-char p1)
|
|
(let ((item-nr 0)
|
|
(items 0))
|
|
(while (search-forward "<li>" p2 t)
|
|
(setq items (1+ items)))
|
|
(goto-char p1)
|
|
(while (< item-nr items)
|
|
(setq item-nr (1+ item-nr))
|
|
(search-forward "<li>" (point-max) t)
|
|
(cond
|
|
((string= list-type "ul") (insert " o "))
|
|
((string= list-type "ol") (insert (format " %s: " item-nr)))
|
|
(t (insert " x "))))))
|
|
|
|
(defun html2text-clean-dtdd (p1 p2)
|
|
(goto-char p1)
|
|
(let ((items 0)
|
|
(item-nr 0))
|
|
(while (search-forward "<dt>" p2 t)
|
|
(setq items (1+ items)))
|
|
(goto-char p1)
|
|
(while (< item-nr items)
|
|
(setq item-nr (1+ item-nr))
|
|
(re-search-forward "<dt>\\([ ]*\\)" (point-max) t)
|
|
(when (match-string 1)
|
|
(delete-region (point) (- (point) (string-width (match-string 1)))))
|
|
(let ((def-p1 (point))
|
|
(def-p2 0))
|
|
(re-search-forward "\\([ ]*\\)\\(</dt>\\|<dd>\\)" (point-max) t)
|
|
(if (match-string 1)
|
|
(progn
|
|
(let* ((mw1 (string-width (match-string 1)))
|
|
(mw2 (string-width (match-string 2)))
|
|
(mw (+ mw1 mw2)))
|
|
(goto-char (- (point) mw))
|
|
(delete-region (point) (+ (point) mw1))
|
|
(setq def-p2 (point))))
|
|
(setq def-p2 (- (point) (string-width (match-string 2)))))
|
|
(put-text-property def-p1 def-p2 'face 'bold)))))
|
|
|
|
(defun html2text-delete-tags (p1 p2 p3 p4)
|
|
(delete-region p1 p2)
|
|
(delete-region (- p3 (- p2 p1)) (- p4 (- p2 p1))))
|
|
|
|
(defun html2text-delete-single-tag (p1 p2)
|
|
(delete-region p1 p2))
|
|
|
|
(defun html2text-clean-hr (p1 p2)
|
|
(html2text-delete-single-tag p1 p2)
|
|
(goto-char p1)
|
|
(newline 1)
|
|
(insert (make-string fill-column ?-)))
|
|
|
|
(defun html2text-clean-ul (p1 p2 p3 p4)
|
|
(html2text-delete-tags p1 p2 p3 p4)
|
|
(html2text-clean-list-items p1 (- p3 (- p1 p2)) "ul"))
|
|
|
|
(defun html2text-clean-ol (p1 p2 p3 p4)
|
|
(html2text-delete-tags p1 p2 p3 p4)
|
|
(html2text-clean-list-items p1 (- p3 (- p1 p2)) "ol"))
|
|
|
|
(defun html2text-clean-dl (p1 p2 p3 p4)
|
|
(html2text-delete-tags p1 p2 p3 p4)
|
|
(html2text-clean-dtdd p1 (- p3 (- p1 p2))))
|
|
|
|
(defun html2text-clean-center (p1 p2 p3 p4)
|
|
(html2text-delete-tags p1 p2 p3 p4)
|
|
(center-region p1 (- p3 (- p2 p1))))
|
|
|
|
(defun html2text-clean-bold (p1 p2 p3 p4)
|
|
(put-text-property p2 p3 'face 'bold)
|
|
(html2text-delete-tags p1 p2 p3 p4))
|
|
|
|
(defun html2text-clean-title (p1 p2 p3 p4)
|
|
(put-text-property p2 p3 'face 'bold)
|
|
(html2text-delete-tags p1 p2 p3 p4))
|
|
|
|
(defun html2text-clean-underline (p1 p2 p3 p4)
|
|
(put-text-property p2 p3 'face 'underline)
|
|
(html2text-delete-tags p1 p2 p3 p4))
|
|
|
|
(defun html2text-clean-italic (p1 p2 p3 p4)
|
|
(put-text-property p2 p3 'face 'italic)
|
|
(html2text-delete-tags p1 p2 p3 p4))
|
|
|
|
(defun html2text-clean-font (p1 p2 p3 p4)
|
|
(html2text-delete-tags p1 p2 p3 p4))
|
|
|
|
(defun html2text-clean-blockquote (p1 p2 p3 p4)
|
|
(html2text-delete-tags p1 p2 p3 p4))
|
|
|
|
(defun html2text-clean-anchor (p1 p2 p3 p4)
|
|
;; If someone can explain how to make the URL clickable I will surely
|
|
;; improve upon this.
|
|
;; Maybe `goto-addr.el' can be used here.
|
|
(let* ((attr-list (html2text-get-attr p1 p2))
|
|
(href (html2text-attr-value attr-list "href")))
|
|
(delete-region p1 p4)
|
|
(when href
|
|
(goto-char p1)
|
|
(insert (substring href 1 -1 ))
|
|
(put-text-property p1 (point) 'face 'bold))))
|
|
|
|
;;
|
|
;; </Functions to be called to format a tag-pair>
|
|
;;
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;;
|
|
;; <Functions to be called to fix up paragraphs>
|
|
;;
|
|
|
|
(defun html2text-fix-paragraph (p1 p2)
|
|
(goto-char p1)
|
|
(let ((refill-start)
|
|
(refill-stop))
|
|
(when (re-search-forward "<br>$" p2 t)
|
|
(goto-char p1)
|
|
(when (re-search-forward ".+[^<][^b][^r][^>]$" p2 t)
|
|
(beginning-of-line)
|
|
(setq refill-start (point))
|
|
(goto-char p2)
|
|
(re-search-backward ".+[^<][^b][^r][^>]$" refill-start t)
|
|
(forward-line 1)
|
|
(end-of-line)
|
|
;; refill-stop should ideally be adjusted to
|
|
;; accomodate the "<br>" strings which are removed
|
|
;; between refill-start and refill-stop. Can simply
|
|
;; be returned from my-replace-string
|
|
(setq refill-stop (+ (point)
|
|
(html2text-replace-string
|
|
"<br>" ""
|
|
refill-start (point))))
|
|
;; (message "Point = %s refill-stop = %s" (point) refill-stop)
|
|
;; (sleep-for 4)
|
|
(fill-region refill-start refill-stop))))
|
|
(html2text-replace-string "<br>" "" p1 p2))
|
|
|
|
;;
|
|
;; This one is interactive ...
|
|
;;
|
|
(defun html2text-fix-paragraphs ()
|
|
"This _tries_ to fix up the paragraphs - this is done in quite a ad-hook
|
|
fashion, quite close to pure guess-work. It does work in some cases though."
|
|
(interactive)
|
|
(goto-char (point-min))
|
|
(while (re-search-forward "^<br>$" nil t)
|
|
(delete-region (match-beginning 0) (match-end 0)))
|
|
;; Removing lonely <br> on a single line, if they are left intact we
|
|
;; dont have any paragraphs at all.
|
|
(goto-char (point-min))
|
|
(while (not (eobp))
|
|
(let ((p1 (point)))
|
|
(forward-paragraph 1)
|
|
;;(message "Kaller fix med p1=%s p2=%s " p1 (1- (point))) (sleep-for 5)
|
|
(html2text-fix-paragraph p1 (1- (point)))
|
|
(goto-char p1)
|
|
(when (not (eobp))
|
|
(forward-paragraph 1)))))
|
|
|
|
;;
|
|
;; </Functions to be called to fix up paragraphs>
|
|
;;
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;;
|
|
;; <Interactive functions>
|
|
;;
|
|
|
|
(defun html2text-remove-tags (tag-list)
|
|
"Removes the tags listed in the list `html2text-remove-tag-list'.
|
|
See the documentation for that variable."
|
|
(interactive)
|
|
(dolist (tag tag-list)
|
|
(goto-char (point-min))
|
|
(while (re-search-forward (format "\\(</?%s[^>]*>\\)" tag) (point-max) t)
|
|
(delete-region (match-beginning 0) (match-end 0)))))
|
|
|
|
(defun html2text-format-tags ()
|
|
"See the variable `html2text-format-tag-list' for documentation."
|
|
(interactive)
|
|
(dolist (tag-and-function html2text-format-tag-list)
|
|
(let ((tag (car tag-and-function))
|
|
(function (cdr tag-and-function)))
|
|
(goto-char (point-min))
|
|
(while (re-search-forward (format "\\(<%s\\( [^>]*\\)?>\\)" tag)
|
|
(point-max) t)
|
|
(let ((p1)
|
|
(p2 (point))
|
|
(p3) (p4))
|
|
(search-backward "<" (point-min) t)
|
|
(setq p1 (point))
|
|
(unless (search-forward (format "</%s>" tag) (point-max) t)
|
|
(goto-char p2)
|
|
(insert (format "</%s>" tag)))
|
|
(setq p4 (point))
|
|
(search-backward "</" (point-min) t)
|
|
(setq p3 (point))
|
|
(funcall function p1 p2 p3 p4)
|
|
(goto-char p1))))))
|
|
|
|
(defun html2text-substitute ()
|
|
"See the variable `html2text-replace-list' for documentation."
|
|
(interactive)
|
|
(dolist (e html2text-replace-list)
|
|
(goto-char (point-min))
|
|
(let ((old-string (car e))
|
|
(new-string (cdr e)))
|
|
(html2text-replace-string old-string new-string (point-min) (point-max)))))
|
|
|
|
(defun html2text-format-single-elements ()
|
|
(interactive)
|
|
(dolist (tag-and-function html2text-format-single-element-list)
|
|
(let ((tag (car tag-and-function))
|
|
(function (cdr tag-and-function)))
|
|
(goto-char (point-min))
|
|
(while (re-search-forward (format "\\(<%s\\( [^>]*\\)?>\\)" tag)
|
|
(point-max) t)
|
|
(let ((p1)
|
|
(p2 (point)))
|
|
(search-backward "<" (point-min) t)
|
|
(setq p1 (point))
|
|
(funcall function p1 p2))))))
|
|
|
|
;;
|
|
;; Main function
|
|
;;
|
|
|
|
;;;###autoload
|
|
(defun html2text ()
|
|
"Convert HTML to plain text in the current buffer."
|
|
(interactive)
|
|
(save-excursion
|
|
(let ((case-fold-search t)
|
|
(buffer-read-only))
|
|
(html2text-remove-tags html2text-remove-tag-list)
|
|
(html2text-format-tags)
|
|
(html2text-remove-tags html2text-remove-tag-list2)
|
|
(html2text-substitute)
|
|
(html2text-format-single-elements)
|
|
(html2text-fix-paragraphs))))
|
|
|
|
;;
|
|
;; </Interactive functions>
|
|
;;
|
|
(provide 'html2text)
|
|
;;; arch-tag: e9e57b79-35d4-4de1-a647-e7e01fe56d1e
|
|
;;; html2text.el ends here
|