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author | Miles Bader <miles@gnu.org> | 2004-09-04 13:13:48 +0000 |
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committer | Miles Bader <miles@gnu.org> | 2004-09-04 13:13:48 +0000 |
commit | 23f87bede063c31c164f97278caabdc5cf5e6980 (patch) | |
tree | 12913439eae89014aa2d810da4861f933d3348ec /lisp/gnus/html2text.el | |
parent | 2a223f35db1bb47fb00f43191e7450b45bbd7fc4 (diff) | |
download | emacs-23f87bede063c31c164f97278caabdc5cf5e6980.tar.gz |
Revision: miles@gnu.org--gnu-2004/emacs--cvs-trunk--0--patch-523
Merge from emacs--gnus--5.10, gnus--rel--5.10
Patches applied:
* miles@gnu.org--gnu-2004/emacs--gnus--5.10--base-0
tag of miles@gnu.org--gnu-2004/emacs--cvs-trunk--0--patch-464
* miles@gnu.org--gnu-2004/emacs--gnus--5.10--patch-1
Import from CVS branch gnus-5_10-branch
* miles@gnu.org--gnu-2004/emacs--gnus--5.10--patch-2
Merge from lorentey@elte.hu--2004/emacs--multi-tty--0, emacs--cvs-trunk--0
* miles@gnu.org--gnu-2004/emacs--gnus--5.10--patch-3
Merge from gnus--rel--5.10
* miles@gnu.org--gnu-2004/emacs--gnus--5.10--patch-4
Merge from gnus--rel--5.10
* miles@gnu.org--gnu-2004/gnus--rel--5.10--patch-18
Update from CVS
* miles@gnu.org--gnu-2004/gnus--rel--5.10--patch-19
Remove autoconf-generated files from archive
* miles@gnu.org--gnu-2004/gnus--rel--5.10--patch-20
Update from CVS
Diffstat (limited to 'lisp/gnus/html2text.el')
-rw-r--r-- | lisp/gnus/html2text.el | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/lisp/gnus/html2text.el b/lisp/gnus/html2text.el new file mode 100644 index 00000000000..f2aefbef993 --- /dev/null +++ b/lisp/gnus/html2text.el @@ -0,0 +1,550 @@ +;;; html2text.el --- a simple html to plain text converter +;; Copyright (C) 2002, 2003 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 2, 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., 59 Temple Place - Suite 330, +;; Boston, MA 02111-1307, 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 + '((" " . " ") (">" . ">") ("<" . "<") (""" . "\"")) + "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. Observe that if you the tags in the list are presented +*without* any \"<\" or \">\". All occurences 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 actual +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) + ("u" . html2text-clean-underline) + ("i" . 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-buffer-head () + (if (string= mode-name "Article") + (beginning-of-buffer) + (beginning-of-buffer) + ) + ) + +(defun html2text-replace-string (from-string to-string p1 p2) + (goto-char p1) + (let ((delta (- (string-width to-string) (string-width from-string))) + (change 0)) + (while (search-forward from-string p2 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 (attr-list attr) + (nth 1 (assoc attr attr-list)) + ) + +(defun html2text-get-attr (p1 p2 tag) + (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) + + (if (not (string-match "=" prev)) + (progn + (if (not (string= (substring this 0 1) "=")) + (setq attr-list (cons (list prev nil) attr-list)) + ) + ) + ) + + (while (< index (1- (length tmp-list))) + (if (not (string-match "=" this)) + (if (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)) + ) + + (if this + (progn + (if (not (string-match "=" this)) + (progn + (if (not (string= (substring prev -1) "=")) + (setq attr-list (cons (list this nil) attr-list)) + ) + ) + ) + ) + ) + attr-list ;; return - value + ) + ) + +;; +;; </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 (re-search-forward "<li>" p2 t) + (setq items (1+ items))) + (goto-char p1) + (while (< item-nr items) + (setq item-nr (1+ item-nr)) + (re-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 (re-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. + (let* ((attr-list (html2text-get-attr p1 p2 "a")) + (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 ((has-br-line) + (refill-start) + (refill-stop)) + (if (re-search-forward "<br>$" p2 t) + (setq has-br-line t) + ) + (if has-br-line + (progn + (goto-char p1) + (if (re-search-forward ".+[^<][^b][^r][^>]$" p2 t) + (progn + (beginning-of-line) + (setq refill-start (point)) + (goto-char p2) + (re-search-backward ".+[^<][^b][^r][^>]$" refill-start t) + (next-line 1) + (end-of-line) + ;; refill-stop should ideally be adjusted to + ;; accomodate the "<br>" strings which are removed + ;; between refill-start and refill-stop. Can simply + ;; be returned from my-replace-string + (setq refill-stop (+ (point) + (html2text-replace-string + "<br>" "" + refill-start (point)))) + ;; (message "Point = %s refill-stop = %s" (point) refill-stop) + ;; (sleep-for 4) + (fill-region refill-start refill-stop) + ) + ) + ) + ) + ) + (html2text-replace-string "<br>" "" p1 p2) + ) + +;; +;; This one is interactive ... +;; +(defun html2text-fix-paragraphs () + "This _tries_ to fix up the paragraphs - this is done in quite a ad-hook +fashion, quite close to pure guess-work. It does work in some cases though." + (interactive) + (html2text-buffer-head) + (replace-regexp "^<br>$" "") + ;; Removing lonely <br> on a single line, if they are left intact we + ;; dont have any paragraphs at all. + (html2text-buffer-head) + (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) + (html2text-buffer-head) + (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))) + (html2text-buffer-head) + (while (re-search-forward (format "\\(<%s\\( [^>]*\\)?>\\)" tag) + (point-max) t) + (let ((p1) + (p2 (point)) + (p3) (p4) + (attr (match-string 1))) + (search-backward "<" (point-min) t) + (setq p1 (point)) + (re-search-forward (format "</%s>" tag) (point-max) t) + (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) + (html2text-buffer-head) + (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))) + (html2text-buffer-head) + (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> +;; + +;;; arch-tag: e9e57b79-35d4-4de1-a647-e7e01fe56d1e +;;; html2text.el ends here |