Newsgroups: gnu.emacs.sources
Subject: html-chooser-mode.el -- use nxml-mode or html-mode, depending
From: public@heslin.eclipse.co.uk
Date: Tue, 28 Jun 2005 16:14:19 +0100
Message-ID: <878y0u1pkk.fsf@heslin.eclipse.co.uk>
;;; html-chooser-mode.el -- use nxml-mode or html-mode, depending, and
;; insert templates for HTML and XHTML.
;;
;; Author: Peter Heslin
;; Version: 1.0
;;
;; Copyright (C) 2005 Peter Heslin
;;
;; This program 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.
;;
;; This program 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, 675 Massachusettes Ave,
;; Cambridge, MA 02139, USA.
;;
;;; Commentary:
;;
;; nxml-mode is an excellent mode for authoring XHTML (see
;; http://www.emacswiki.org/cgi-bin/wiki/NxmlModeForXHTML), but it
;; only works for XHTML. Even people who prefer XHTML still must often
;; deal with legacy HTML documents, and so many people need to work
;; with files in both flavors. Unfortunately, both usually have the
;; same .html or .htm extension, and so are treated identically by
;; auto-mode-alist. If, as a result, you accidentally open an HTML
;; file in nxml-mode, Emacs churns CPU while it tried in vain to
;; validate it, until you kill the buffer.
;;
;; This file provides a dummy major mode called html-chooser-mode that
;; looks at a file, and if it seems to be XHTML, switches to
;; nxml-mode, and if it seems to be regular HTML, switches to
;; html-mode (or html-helper-mode, or whatever). If the file is empty
;; or otherwise cannot be understood, the user is prompted to choose
;; which mode, and if the file is empty, is offered the possibility of
;; inserting several skeletons or templates appropriate to that mode.
;;
;; In fact, you may not need html-chooser-mode at all, since you can
;; get most of its functionality by putting this in your .emacs file:
;;
;; (setq magic-mode-alist (cons '("<\\?xml\\s " . nxml-mode) magic-mode-alist))
;; (setq auto-mode-alist (cons '("\\.x?html?$" . html-mode) auto-mode-alist))
;;
;; In this way, all files with a .html extension will be opened in
;; html-mode, except for those containing
")
(defvar html-chooser-mode-doctype-alist
'((xhtml11 . "")
(trxhtml10 . "")
(strxhtml10 . "")
(frxhtml10 . "")
(trhtml401 . "")
(strhtml401 . "")
(frhtml401 . "")
(html32 . "")
(html20 . "")))
(defvar html-chooser-mode-default-doctypes
'((xhtml . "xhtml 1.1")
(html . "transitional html 4.01")))
(defvar html-chooser-mode-skeleton-alist
'((xhtml .
"
")
(html .
"
")))
(defun html-chooser-mode ()
(interactive)
(goto-char (point-min))
(if (or (looking-at "\\s *<\\?xml\\s ")
(re-search-forward "<[Hh][Tt][Mm][Ll]\\s xmlns=.*xhtml" nil t))
;; looks like XHTML
(funcall html-chooser-mode-xhtml-mode)
(goto-char (point-min))
(if (re-search-forward
"<\\([hH][tT][mM][lL]\\|[hH][eE][aA][dD]\\|[bB][oO][dD][yY]\\)" nil t)
;; looks like HTML
(funcall html-chooser-mode-html-mode)
(let ((type (if (y-or-n-p "Is this going to be an XHTML file? ") 'xhtml 'html)))
(when (y-or-n-p "Do you want to insert a template? ")
(html-chooser-mode-insert-template type))
(funcall (if (eq type 'xhtml)
html-chooser-mode-xhtml-mode
html-chooser-mode-html-mode))))))
(defun html-chooser-mode-insert-template (type)
(let* ((choices
(if (eq type 'xhtml)
'(("xhtml 1.1" . xhtml11)
("transitional xhtml 1.0" . trxhtml10)
("strict xhtml 1.0" . strxhtml10)
("frameset xhtml 1.0" . frxhtml10))
'(("transitional html 4.01" . trhtml401)
("strict html 4.01" . strhtml401)
("frameset html 4.01" . frhtml401)
("html 3.2" . html32)
("html 2.0" . html20))))
(default
(cdr (assoc type html-chooser-mode-default-doctypes)))
(style (cdr (assoc
(completing-read "Style: " choices nil t default) choices))))
(goto-char (point-min))
(when (eq type 'xhtml)
(insert html-chooser-mode-xml-declaration))
(when style
(insert (cdr (assoc style html-chooser-mode-doctype-alist))
"\n"))
(insert (cdr (assoc type html-chooser-mode-skeleton-alist)))
(goto-char (point-min))
(re-search-forward "<[Tt][Ii][Tt][Ll][Ee]>" nil t)))
(provide 'html-chooser-mode)