(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. 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.")
(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))
(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
((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))))
((string-match "[^ ]=\\'" prev)
(setq attr-list (cons (list (substring prev 0 -1) this) attr-list))))
(while (< index (length tmp-list))
(cond
((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))))
((string-match "\\`=[^ ]" this)
(setq attr-list (cons (list prev (substring this 1)) attr-list)))
((string-match "[^ ]=\\'" this)
(setq attr-list (cons (list (substring this 0 -1) next) attr-list)))
((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)))
(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)))
attr-list))
(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)
(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))))
(defun html2text-fix-paragraph (p1 p2)
(goto-char p1)
(let ((has-br-line)
(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][^>]$" refill-start t)
(next-line 1)
(end-of-line)
(setq refill-stop (+ (point)
(html2text-replace-string
"<br>" ""
refill-start (point))))
(fill-region refill-start refill-stop))))
(html2text-replace-string "<br>" "" p1 p2))
(defun html2text-fix-paragraphs ()
"This _tries_ to fix up the paragraphs - this is done in quite a ad-hook
fashion, quite close to pure guess-work. It does work in some cases though."
(interactive)
(goto-char (point-min))
(while (re-search-forward "^<br>$" nil t)
(delete-region (match-beginning 0) (match-end 0)))
(goto-char (point-min))
(while (not (eobp))
(let ((p1 (point)))
(forward-paragraph 1)
(html2text-fix-paragraph p1 (1- (point)))
(goto-char p1)
(when (not (eobp))
(forward-paragraph 1)))))
(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))))))
(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))))
(provide 'html2text)