--- /dev/null
+;;; xml-lite.el --- an indentation-engine for XML
+
+;; Copyright (C) 2001 Mike Williams <mdub@bigfoot.com>
+
+;; Author: Mike Williams <mdub@bigfoot.com>
+;; Created: February 2001
+;; Version: $Revision: 1.24 $
+;; Keywords: xml
+
+;; This file is part of GNU Emacs.
+
+;; 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 of the License, 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, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;; Commentary:
+;;
+;; This package provides a simple indentation engine for XML. It is
+;; intended for use in situations where the full power of the popular PSGML
+;; package (DTD parsing, syntax checking) is not required.
+;;
+;; xml-lite is designed to be used in conjunction with the default GNU
+;; Emacs sgml-mode, to provide a lightweight XML-editing environment.
+;;
+;; Updates will be made available at:
+;; http://www.bigfoot.com/~mdub/software/xml-lite.el
+;;
+;; Note: the font-lock support that was in this package has been removed.
+
+;;; Thanks:
+;;
+;; Jens Schmidt <Jens.Schmidt@oracle.com>
+;; for his feedback and suggestions
+
+;;; Code:
+
+(eval-when-compile (require 'cl))
+(require 'sgml-mode)
+(require 'custom)
+
+\f
+;; Variables
+
+(defgroup xml-lite nil
+ "Customizable variables for XML-Lite mode."
+ :group 'languages
+ )
+
+(defcustom xml-lite-indent-offset 4
+ "*Specifies the default indentation level for `xml-lite-indent-line'."
+ :type 'integer
+ :group 'xml-lite
+ )
+
+(defcustom xml-lite-indent-comment-offset 5
+ "*Specifies the indentation level for XML comments."
+ :type 'integer
+ :group 'xml-lite
+ )
+
+(defcustom xml-lite-electric-slash 'close
+ "*If non-nil, inserting a '/' after a '<' behaves electrically.
+If set to `indent', typing '</' just triggers reindentation.
+If set to `close', typing '</' inserts an end-tag for the
+enclosing XML element."
+ :type '(choice (const :tag "Indent" indent)
+
+ (const :tag "Close" close)
+ (const :tag "No" nil))
+
+ :group 'xml-lite
+ )
+
+(defcustom xml-lite-mode-line-string " XML"
+ "*String to display in the modeline when `xml-lite-mode' is active.
+Set this to nil if you don't want a modeline indicator for xml-lite-mode."
+ :type 'string
+ :group 'xml-lite)
+
+(defcustom xml-lite-mode-hook nil
+ "*Hook called by `xml-lite-mode'."
+ :type 'hook
+ :group 'xml-lite)
+
+;;;###autoload
+(defvar xml-lite-mode nil
+ "Non-nil if `xml-lite-mode' is enabled.")
+(make-variable-buffer-local 'xml-lite-mode)
+
+\f
+;; Parsing
+
+(defstruct (xml-lite-tag
+ (:constructor xml-lite-make-tag (type start end name name-end)))
+ type start end name name-end)
+
+(defsubst xml-lite-parse-tag-name ()
+ "Skip past a tag-name, and return the name."
+ (let ((here (point)))
+ (if (> (skip-chars-forward "-._:A-Za-z0-9") 0)
+ (buffer-substring-no-properties here (point)))))
+
+(defun xml-lite-parse-tag-backward ()
+ "Get information about the parent tag."
+ (let ((limit (point))
+ (tag-type 'open)
+ (tag-start (search-backward "<" nil t))
+ tag-end name name-end)
+
+ (if (not tag-start) nil
+ (setq tag-end (search-forward ">" limit t))
+
+ ;; determine tag type
+ (goto-char (1+ tag-start))
+ (cond
+
+ ((= ?? (char-after)) ; processing-instruction
+ (setq tag-type 'pi))
+
+ ((= ?! (char-after)) ; declaration
+ (setq tag-type 'decl)
+ (cond
+ ((looking-at "!--") ; comment
+ (setq tag-type 'comment
+ tag-end (search-forward "-->" nil t)))
+ ((looking-at "!\\[CDATA\\[") ; cdata
+ (setq tag-type 'cdata
+ tag-end (search-forward "]]>" nil t)))
+ (t
+ (ignore-errors
+ (goto-char tag-start)
+ (forward-sexp 1)
+ (setq tag-end (point))))))
+
+ ((= ?% (char-after)) ; JSP tag
+ (setq tag-type 'jsp
+ tag-end (search-forward "%>" nil t)))
+
+ ((= ?/ (char-after)) ; close-tag
+ (goto-char (+ 2 tag-start))
+ (setq tag-type 'close
+ name (xml-lite-parse-tag-name)
+ name-end (point)))
+
+ (t
+ (setq tag-type 'open
+ name (xml-lite-parse-tag-name)
+ name-end (point))
+ ;; check whether it's an empty tag
+ (if (and tag-end (eq ?/ (char-before (- tag-end 1))))
+ (setq tag-type 'empty))))
+
+ (goto-char tag-start)
+ (xml-lite-make-tag tag-type tag-start tag-end name name-end))))
+
+(defsubst xml-lite-at-indentation-p ()
+ "Return true if point is at the first non-whitespace character on the line."
+ (save-excursion
+ (skip-chars-backward " \t")
+ (bolp)))
+
+(defsubst xml-lite-inside-tag-p (tag-info &optional point)
+ "Return true if TAG-INFO contains the POINT."
+ (let ((end (xml-lite-tag-end tag-info))
+ (point (or point (point))))
+ (or (null end)
+ (> end point))))
+
+(defun xml-lite-get-context (&optional full)
+ "Determine the context of the current position.
+If FULL is non-nil, parse back to the beginning of the buffer, otherwise
+parse until we find a start-tag as the first thing on a line.
+
+The context is a list of tag-info structures. The last one is the tag
+immediately enclosing the current position."
+ (let ((here (point))
+ (level 0)
+ tag-info context)
+ (save-excursion
+
+ (while
+ (and (or (not context)
+ full
+ (not (xml-lite-at-indentation-p)))
+ (setq tag-info (xml-lite-parse-tag-backward)))
+
+ (cond
+
+ ;; inside a tag ...
+ ((xml-lite-inside-tag-p tag-info here)
+ (setq context (cons tag-info context)))
+
+ ;; start-tag
+ ((eq (xml-lite-tag-type tag-info) 'open)
+ (setq level (1- level))
+ (when (= level -1)
+ (setq context (cons tag-info context))
+ (setq level 0)))
+
+ ;; end-tag
+ ((eq (xml-lite-tag-type tag-info) 'close)
+ (setq level (1+ level)))
+
+ )))
+
+ ;; return context
+ context
+ ))
+
+(defun xml-lite-show-context (&optional full)
+ "Display the current context.
+If FULL is non-nil, parse back to the beginning of the buffer."
+ (interactive "P")
+ (with-output-to-temp-buffer "*XML Context*"
+ (pp (xml-lite-get-context full))))
+
+\f
+;; Indenting
+
+(defun xml-lite-calculate-indent ()
+ "Calculate the column to which this line should be indented."
+ (let* ((here (point))
+ (context (xml-lite-get-context))
+ (ref-tag-info (car context))
+ (last-tag-info (car (last context))))
+
+ (save-excursion
+ (cond
+
+ ;; no context
+ ((null context)
+ 0)
+
+ ;; inside a comment
+ ((eq 'comment (xml-lite-tag-type last-tag-info))
+ (goto-char (xml-lite-tag-start last-tag-info))
+ (+ (current-column) xml-lite-indent-comment-offset))
+
+ ;; inside a tag
+ ((xml-lite-inside-tag-p last-tag-info here)
+ (let ((syntax-info
+ (parse-partial-sexp (xml-lite-tag-start last-tag-info)
+ (point))))
+ (cond
+ ;; inside a string
+ ((nth 3 syntax-info)
+ (goto-char (nth 8 syntax-info))
+ (1+ (current-column)))
+ ;; if we have a tag-name, base indent on that
+ ((and (xml-lite-tag-name-end last-tag-info)
+ (progn
+ (goto-char (xml-lite-tag-name-end last-tag-info))
+ (not (looking-at "[ \t]*$"))))
+ (1+ (current-column)))
+ ;; otherwise, add indent-offset
+ (t
+ (goto-char (xml-lite-tag-start last-tag-info))
+ (+ (current-column) xml-lite-indent-offset)))))
+
+ ;; inside an element
+ (t
+ ;; indent to start of tag
+ (let ((here (point))
+ indent-col)
+ (goto-char (xml-lite-tag-start ref-tag-info))
+ (setq indent-col (current-column))
+ (goto-char here)
+ ;; add xml-lite-indent-offset, unless we're looking at the matching
+ ;; end-tag
+ (unless (and (eq (length context) 1) (looking-at "</"))
+ (setq indent-col (+ indent-col xml-lite-indent-offset)))
+ indent-col))
+
+ ))))
+
+(defun xml-lite-indent-line ()
+ "Indent the current line as XML."
+ (interactive)
+ (let ((origin-point (point))
+ bol-point indent-point
+ indent-col)
+
+ ;; save beginning of line
+ (beginning-of-line)
+ (setq bol-point (point))
+ ;; save current indent
+ (skip-chars-forward " \t")
+ (setq indent-point (point))
+
+ ;; calculate basic indent
+ (setq indent-col (xml-lite-calculate-indent))
+
+ (unless (eq (current-column) indent-col)
+ ;; re-indent, adjusting origin point for indentation change
+ (delete-region bol-point (point))
+ (indent-to indent-col)
+ (setq origin-point (+ origin-point (- (point) indent-point))))
+
+ (if (> origin-point (point))
+ (goto-char origin-point))
+
+ ))
+
+\f
+;; Editing shortcuts
+
+(defun xml-lite-insert-end-tag ()
+ "Insert an end-tag for the current element."
+ (interactive)
+ (let* ((context (xml-lite-get-context))
+ (tag-info (car (last context)))
+ (type (and tag-info (xml-lite-tag-type tag-info))))
+
+ (cond
+
+ ((null context)
+ (error "Nothing to close"))
+
+ ;; inside a tag
+ ((xml-lite-inside-tag-p tag-info)
+ (cond
+ ((eq type 'open) (insert " />"))
+ ((eq type 'comment) (insert " -->"))
+ ((eq type 'cdata) (insert "]]>"))
+ ((eq type 'jsp) (insert "%>"))
+ ((eq type 'pi) (insert "?>"))
+ (t (insert ">"))))
+
+ ;; inside an element
+ ((eq type 'open)
+ (insert "</" (xml-lite-tag-name tag-info) ">")
+ (xml-lite-indent-line))
+
+ (t
+ (error "Nothing to close")))))
+
+(defun xml-lite-slash (arg)
+ "Insert ARG slash characters.
+Behaves electrically if `xml-lite-electric-slash' is non-nil."
+ (interactive "p")
+ (cond
+ ((not (and (eq (char-before) ?<) (= arg 1)))
+ (insert-char ?/ arg))
+ ((eq xml-lite-electric-slash 'indent)
+ (insert-char ?/ 1)
+ (xml-lite-indent-line))
+ ((eq xml-lite-electric-slash 'close)
+ (delete-backward-char 1)
+ (xml-lite-insert-end-tag))
+ (t
+ (insert-char ?/ arg))))
+
+\f
+;; Movement commands
+
+(defun forward-xml-tag (arg)
+ "Move forward ARG XML-tags."
+ (interactive "p")
+ (cond
+ ((> arg 0)
+ (search-forward ">" nil nil arg))
+ ((< arg 0)
+ (search-backward "<" nil nil (- arg)))
+ ))
+
+(defun backward-xml-tag (arg)
+ "Move backward ARG XML-tags."
+ (interactive "p")
+ (forward-xml-tag (- arg)))
+
+(defun beginning-of-xml-tag ()
+ "Move to the beginning of the current XML-tag."
+ (interactive)
+ (if (= ?< (char-after (point)))
+ (point)
+ (search-backward "<")))
+
+(defun end-of-xml-tag ()
+ "Move to the end of the current XML-tag."
+ (interactive)
+ (forward-xml-tag 1))
+
+\f
+;; Keymap
+
+(defvar xml-lite-mode-map
+ (let ((map (make-sparse-keymap)))
+ (define-key map "\t" 'indent-for-tab-command)
+ (define-key map "\C-c/" 'xml-lite-insert-end-tag)
+ (define-key map "\C-c\C-s" 'xml-lite-show-context)
+ (define-key map "/" 'xml-lite-slash)
+ map)
+ "Key bindings for `xml-lite-mode'.")
+
+\f
+;; Minor mode
+
+;;;###autoload
+(define-minor-mode xml-lite-mode
+ "Toggle `xml-lite-mode'.
+With ARG, enable xml-lite-mode if and only if ARG is positive.
+
+xml-lite-mode provides indentation for XML tags. The value of
+`xml-lite-indent-offset' determines the amount of indentation.
+
+Key bindings:
+\\{xml-lite-mode-map}"
+ nil ; initial value
+ " XML" ; mode indicator
+ 'xml-lite-mode-map ; keymap
+ (if xml-lite-mode
+ (progn
+ (if (eq major-mode 'fundamental-mode)
+ (sgml-mode))
+ (make-local-variable 'indent-line-function)
+ (setq xml-lite-mode t
+ xml-lite-orig-indent-line-function indent-line-function
+ indent-line-function 'xml-lite-indent-line))
+ (setq indent-line-function xml-lite-orig-indent-line-function))
+ (force-mode-line-update))
+
+(provide 'xml-lite)
+
+;;; xml-lite.el ends here
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