mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-21 10:24:55 +00:00
505 lines
16 KiB
EmacsLisp
505 lines
16 KiB
EmacsLisp
;; @(#) xml.el --- XML parser
|
|
|
|
;; Copyright (C) 2000 Free Software Foundation, Inc.
|
|
|
|
;; Author: Emmanuel Briot <briot@gnat.com>
|
|
;; Maintainer: Emmanuel Briot <briot@gnat.com>
|
|
;; Keywords: xml
|
|
|
|
;; 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:
|
|
|
|
;; This file contains a full XML parser. It parses a file, and returns a list
|
|
;; that can be used internally by any other lisp file.
|
|
;; See some example in todo.el
|
|
|
|
;;; FILE FORMAT
|
|
|
|
;; It does not parse the DTD, if present in the XML file, but knows how to
|
|
;; ignore it. The XML file is assumed to be well-formed. In case of error, the
|
|
;; parsing stops and the XML file is shown where the parsing stopped.
|
|
;;
|
|
;; It also knows how to ignore comments, as well as the special ?xml? tag
|
|
;; in the XML file.
|
|
;;
|
|
;; The XML file should have the following format:
|
|
;; <node1 attr1="name1" attr2="name2" ...> value
|
|
;; <node2 attr3="name3" attr4="name4"> value2 </node2>
|
|
;; <node3 attr5="name5" attr6="name6"> value3 </node3>
|
|
;; </node1>
|
|
;; Of course, the name of the nodes and attributes can be anything. There can
|
|
;; be any number of attributes (or none), as well as any number of children
|
|
;; below the nodes.
|
|
;;
|
|
;; There can be only top level node, but with any number of children below.
|
|
|
|
;;; LIST FORMAT
|
|
|
|
;; The functions `xml-parse-file' and `xml-parse-tag' return a list with
|
|
;; the following format:
|
|
;;
|
|
;; xml-list ::= (node node ...)
|
|
;; node ::= (tag_name attribute-list . child_node_list)
|
|
;; child_node_list ::= child_node child_node ...
|
|
;; child_node ::= node | string
|
|
;; tag_name ::= string
|
|
;; attribute_list ::= (("attribute" . "value") ("attribute" . "value") ...)
|
|
;; | nil
|
|
;; string ::= "..."
|
|
;;
|
|
;; Some macros are provided to ease the parsing of this list
|
|
|
|
;;; Code:
|
|
|
|
;;*******************************************************************
|
|
;;**
|
|
;;** Macros to parse the list
|
|
;;**
|
|
;;*******************************************************************
|
|
|
|
(defmacro xml-node-name (node)
|
|
"Return the tag associated with NODE.
|
|
The tag is a lower-case symbol."
|
|
(list 'car node))
|
|
|
|
(defmacro xml-node-attributes (node)
|
|
"Return the list of attributes of NODE.
|
|
The list can be nil."
|
|
(list 'nth 1 node))
|
|
|
|
(defmacro xml-node-children (node)
|
|
"Return the list of children of NODE.
|
|
This is a list of nodes, and it can be nil."
|
|
(list 'cddr node))
|
|
|
|
(defun xml-get-children (node child-name)
|
|
"Return the children of NODE whose tag is CHILD-NAME.
|
|
CHILD-NAME should be a lower case symbol."
|
|
(let ((children (xml-node-children node))
|
|
match)
|
|
(while children
|
|
(if (car children)
|
|
(if (equal (xml-node-name (car children)) child-name)
|
|
(set 'match (append match (list (car children))))))
|
|
(set 'children (cdr children)))
|
|
match))
|
|
|
|
(defun xml-get-attribute (node attribute)
|
|
"Get from NODE the value of ATTRIBUTE.
|
|
An empty string is returned if the attribute was not found."
|
|
(if (xml-node-attributes node)
|
|
(let ((value (assoc attribute (xml-node-attributes node))))
|
|
(if value
|
|
(cdr value)
|
|
""))
|
|
""))
|
|
|
|
;;*******************************************************************
|
|
;;**
|
|
;;** Creating the list
|
|
;;**
|
|
;;*******************************************************************
|
|
|
|
(defun xml-parse-file (file &optional parse-dtd)
|
|
"Parse the well-formed XML FILE.
|
|
Returns the top node with all its children.
|
|
If PARSE-DTD is non-nil, the DTD is parsed rather than skipped."
|
|
(find-file file)
|
|
(let ((xml (xml-parse-region (point-min)
|
|
(point-max)
|
|
(current-buffer)
|
|
parse-dtd)))
|
|
(kill-buffer (current-buffer))
|
|
xml))
|
|
|
|
(defun xml-parse-region (beg end &optional buffer parse-dtd)
|
|
"Parse the region from BEG to END in BUFFER.
|
|
If BUFFER is nil, it defaults to the current buffer.
|
|
Returns the XML list for the region, or raises an error if the region
|
|
is not a well-formed XML file.
|
|
If PARSE-DTD is non-nil, the DTD is parsed rather than skipped,
|
|
and returned as the first element of the list"
|
|
(let (xml result dtd)
|
|
(save-excursion
|
|
(if buffer
|
|
(set-buffer buffer))
|
|
(goto-char beg)
|
|
(while (< (point) end)
|
|
(if (search-forward "<" end t)
|
|
(progn
|
|
(forward-char -1)
|
|
(if (null xml)
|
|
(progn
|
|
(set 'result (xml-parse-tag end parse-dtd))
|
|
(cond
|
|
((listp (car result))
|
|
(set 'dtd (car result))
|
|
(add-to-list 'xml (cdr result)))
|
|
(t
|
|
(add-to-list 'xml result))))
|
|
|
|
;; translation of rule [1] of XML specifications
|
|
(error "XML files can have only one toplevel tag.")))
|
|
(goto-char end)))
|
|
(if parse-dtd
|
|
(cons dtd (reverse xml))
|
|
(reverse xml)))))
|
|
|
|
|
|
(defun xml-parse-tag (end &optional parse-dtd)
|
|
"Parse the tag that is just in front of point.
|
|
The end tag must be found before the position END in the current buffer.
|
|
If PARSE-DTD is non-nil, the DTD of the document, if any, is parsed and
|
|
returned as the first element in the list.
|
|
Returns one of:
|
|
- a list : the matching node
|
|
- nil : the point is not looking at a tag.
|
|
- a cons cell: the first element is the DTD, the second is the node"
|
|
(cond
|
|
;; Processing instructions (like the <?xml version="1.0"?> tag at the
|
|
;; beginning of a document)
|
|
((looking-at "<\\?")
|
|
(search-forward "?>" end)
|
|
(skip-chars-forward " \t\n")
|
|
(xml-parse-tag end))
|
|
;; Character data (CDATA) sections, in which no tag should be interpreted
|
|
((looking-at "<!\\[CDATA\\[")
|
|
(let ((pos (match-end 0)))
|
|
(unless (search-forward "]]>" end t)
|
|
(error "CDATA section does not end anywhere in the document"))
|
|
(buffer-substring-no-properties pos (match-beginning 0))))
|
|
;; DTD for the document
|
|
((looking-at "<!DOCTYPE")
|
|
(let (dtd)
|
|
(if parse-dtd
|
|
(set 'dtd (xml-parse-dtd end))
|
|
(xml-skip-dtd end))
|
|
(skip-chars-forward " \t\n")
|
|
(if dtd
|
|
(cons dtd (xml-parse-tag end))
|
|
(xml-parse-tag end))))
|
|
;; skip comments
|
|
((looking-at "<!--")
|
|
(search-forward "-->" end)
|
|
(skip-chars-forward " \t\n")
|
|
(xml-parse-tag end))
|
|
;; end tag
|
|
((looking-at "</")
|
|
'())
|
|
;; opening tag
|
|
((looking-at "<\\([^/> \t]+\\)")
|
|
(let* ((node-name (match-string 1))
|
|
(children (list (intern node-name)))
|
|
pos)
|
|
(goto-char (match-end 1))
|
|
|
|
;; parses the attribute list
|
|
(set 'children (append children (list (xml-parse-attlist end))))
|
|
|
|
;; is this an empty element ?
|
|
(if (looking-at "/>")
|
|
(progn
|
|
(forward-char 2)
|
|
(skip-chars-forward " \t\n")
|
|
(append children '("")))
|
|
|
|
;; is this a valid start tag ?
|
|
(if (= (char-after) ?>)
|
|
(progn
|
|
(forward-char 1)
|
|
(skip-chars-forward " \t\n")
|
|
(while (not (looking-at (concat "</" node-name ">")))
|
|
(cond
|
|
((looking-at "</")
|
|
(error (concat
|
|
"XML: invalid syntax -- invalid end tag (expecting "
|
|
node-name
|
|
")")))
|
|
((= (char-after) ?<)
|
|
(set 'children (append children (list (xml-parse-tag end)))))
|
|
(t
|
|
(set 'pos (point))
|
|
(search-forward "<" end)
|
|
(forward-char -1)
|
|
(let ((string (buffer-substring-no-properties pos (point)))
|
|
(pos 0))
|
|
|
|
;; Clean up the string (no newline characters)
|
|
;; Not done, since as per XML specifications, the XML processor
|
|
;; should always pass the whole string to the application.
|
|
;; (while (string-match "\\s +" string pos)
|
|
;; (set 'string (replace-match " " t t string))
|
|
;; (set 'pos (1+ (match-beginning 0))))
|
|
|
|
(set 'children (append children
|
|
(list (xml-substitute-special string))))))))
|
|
(goto-char (match-end 0))
|
|
(skip-chars-forward " \t\n")
|
|
(if (> (point) end)
|
|
(error "XML: End tag for %s not found before end of region."
|
|
node-name))
|
|
children
|
|
)
|
|
|
|
;; This was an invalid start tag
|
|
(error "XML: Invalid attribute list")
|
|
))))
|
|
))
|
|
|
|
(defun xml-parse-attlist (end)
|
|
"Return the attribute-list that point is looking at.
|
|
The search for attributes end at the position END in the current buffer.
|
|
Leaves the point on the first non-blank character after the tag."
|
|
(let ((attlist '())
|
|
name)
|
|
(skip-chars-forward " \t\n")
|
|
(while (looking-at "\\([a-zA-Z_:][a-zA-Z0-9.-_:]*\\)[ \t\n]*=[ \t\n]*")
|
|
(set 'name (intern (match-string 1)))
|
|
(goto-char (match-end 0))
|
|
|
|
;; Do we have a string between quotes (or double-quotes),
|
|
;; or a simple word ?
|
|
(unless (looking-at "\"\\([^\"]+\\)\"")
|
|
(unless (looking-at "'\\([^\"]+\\)'")
|
|
(error "XML: Attribute values must be given between quotes.")))
|
|
|
|
;; Each attribute must be unique within a given element
|
|
(if (assoc name attlist)
|
|
(error "XML: each attribute must be unique within an element."))
|
|
|
|
(set 'attlist (append attlist
|
|
(list (cons name (match-string 1)))))
|
|
(goto-char (match-end 0))
|
|
(skip-chars-forward " \t\n")
|
|
(if (> (point) end)
|
|
(error "XML: end of attribute list not found before end of region."))
|
|
)
|
|
attlist
|
|
))
|
|
|
|
;;*******************************************************************
|
|
;;**
|
|
;;** The DTD (document type declaration)
|
|
;;** The following functions know how to skip or parse the DTD of
|
|
;;** a document
|
|
;;**
|
|
;;*******************************************************************
|
|
|
|
(defun xml-skip-dtd (end)
|
|
"Skip the DTD that point is looking at.
|
|
The DTD must end before the position END in the current buffer.
|
|
The point must be just before the starting tag of the DTD.
|
|
This follows the rule [28] in the XML specifications."
|
|
(forward-char (length "<!DOCTYPE"))
|
|
(if (looking-at "[ \t\n]*>")
|
|
(error "XML: invalid DTD (excepting name of the document)"))
|
|
(condition-case nil
|
|
(progn
|
|
(forward-word 1) ;; name of the document
|
|
(skip-chars-forward " \t\n")
|
|
(if (looking-at "\\[")
|
|
(re-search-forward "\\][ \t\n]*>" end)
|
|
(search-forward ">" end)))
|
|
(error (error "XML: No end to the DTD"))))
|
|
|
|
(defun xml-parse-dtd (end)
|
|
"Parse the DTD that point is looking at.
|
|
The DTD must end before the position END in the current buffer."
|
|
(let (dtd type element end-pos)
|
|
(forward-char (length "<!DOCTYPE"))
|
|
(skip-chars-forward " \t\n")
|
|
(if (looking-at ">")
|
|
(error "XML: invalid DTD (excepting name of the document)"))
|
|
|
|
;; Get the name of the document
|
|
(looking-at "\\sw+")
|
|
(set 'dtd (list 'dtd (match-string-no-properties 0)))
|
|
(goto-char (match-end 0))
|
|
|
|
(skip-chars-forward " \t\n")
|
|
|
|
;; External DTDs => don't know how to handle them yet
|
|
(if (looking-at "SYSTEM")
|
|
(error "XML: Don't know how to handle external DTDs."))
|
|
|
|
(if (not (= (char-after) ?\[))
|
|
(error "XML: Unknown declaration in the DTD."))
|
|
|
|
;; Parse the rest of the DTD
|
|
(forward-char 1)
|
|
(while (and (not (looking-at "[ \t\n]*\\]"))
|
|
(<= (point) end))
|
|
(cond
|
|
|
|
;; Translation of rule [45] of XML specifications
|
|
((looking-at
|
|
"[\t \n]*<!ELEMENT[ \t\n]+\\([a-zA-Z0-9.%;]+\\)[ \t\n]+\\([^>]+\\)>")
|
|
|
|
(setq element (intern (match-string-no-properties 1))
|
|
type (match-string-no-properties 2))
|
|
(set 'end-pos (match-end 0))
|
|
|
|
;; Translation of rule [46] of XML specifications
|
|
(cond
|
|
((string-match "^EMPTY[ \t\n]*$" type) ;; empty declaration
|
|
(set 'type 'empty))
|
|
((string-match "^ANY[ \t\n]*$" type) ;; any type of contents
|
|
(set 'type 'any))
|
|
((string-match "^(\\(.*\\))[ \t\n]*$" type) ;; children ([47])
|
|
(set 'type (xml-parse-elem-type (match-string-no-properties 1 type))))
|
|
((string-match "^%[^;]+;[ \t\n]*$" type) ;; substitution
|
|
nil)
|
|
(t
|
|
(error "XML: Invalid element type in the DTD")))
|
|
|
|
;; rule [45]: the element declaration must be unique
|
|
(if (assoc element dtd)
|
|
(error "XML: elements declaration must be unique in a DTD (<%s>)."
|
|
(symbol-name element)))
|
|
|
|
;; Store the element in the DTD
|
|
(set 'dtd (append dtd (list (list element type))))
|
|
(goto-char end-pos)
|
|
)
|
|
|
|
|
|
(t
|
|
(error "XML: Invalid DTD item"))
|
|
)
|
|
)
|
|
|
|
;; Skip the end of the DTD
|
|
(search-forward ">" end)
|
|
dtd
|
|
))
|
|
|
|
|
|
(defun xml-parse-elem-type (string)
|
|
"Convert a STRING for an element type into an elisp structure."
|
|
|
|
(let (elem modifier)
|
|
(if (string-match "(\\([^)]+\\))\\([+*?]?\\)" string)
|
|
(progn
|
|
(setq elem (match-string 1 string)
|
|
modifier (match-string 2 string))
|
|
(if (string-match "|" elem)
|
|
(set 'elem (append '(choice)
|
|
(mapcar 'xml-parse-elem-type
|
|
(split-string elem "|"))))
|
|
(if (string-match "," elem)
|
|
(set 'elem (append '(seq)
|
|
(mapcar 'xml-parse-elem-type
|
|
(split-string elem ","))))
|
|
)))
|
|
(if (string-match "[ \t\n]*\\([^+*?]+\\)\\([+*?]?\\)" string)
|
|
(setq elem (match-string 1 string)
|
|
modifier (match-string 2 string))))
|
|
|
|
(if (and (stringp elem)
|
|
(string= elem "#PCDATA"))
|
|
(set 'elem 'pcdata))
|
|
|
|
(cond
|
|
((string= modifier "+")
|
|
(list '+ elem))
|
|
((string= modifier "*")
|
|
(list '* elem))
|
|
((string= modifier "?")
|
|
(list '? elem))
|
|
(t
|
|
elem))))
|
|
|
|
|
|
;;*******************************************************************
|
|
;;**
|
|
;;** Substituting special XML sequences
|
|
;;**
|
|
;;*******************************************************************
|
|
|
|
(defun xml-substitute-special (string)
|
|
"Return STRING, after subsituting special XML sequences."
|
|
(while (string-match "&" string)
|
|
(set 'string (replace-match "&" t nil string)))
|
|
(while (string-match "<" string)
|
|
(set 'string (replace-match "<" t nil string)))
|
|
(while (string-match ">" string)
|
|
(set 'string (replace-match ">" t nil string)))
|
|
(while (string-match "'" string)
|
|
(set 'string (replace-match "'" t nil string)))
|
|
(while (string-match """ string)
|
|
(set 'string (replace-match "\"" t nil string)))
|
|
string)
|
|
|
|
;;*******************************************************************
|
|
;;**
|
|
;;** Printing a tree.
|
|
;;** This function is intended mainly for debugging purposes.
|
|
;;**
|
|
;;*******************************************************************
|
|
|
|
(defun xml-debug-print (xml)
|
|
(while xml
|
|
(xml-debug-print-internal (car xml) "")
|
|
(set 'xml (cdr xml)))
|
|
)
|
|
|
|
(defun xml-debug-print-internal (xml &optional indent-string)
|
|
"Outputs the XML tree in the current buffer.
|
|
The first line indented with INDENT-STRING."
|
|
(let ((tree xml)
|
|
attlist)
|
|
(unless indent-string
|
|
(set 'indent-string ""))
|
|
|
|
(insert indent-string "<" (symbol-name (xml-node-name tree)))
|
|
|
|
;; output the attribute list
|
|
(set 'attlist (xml-node-attributes tree))
|
|
(while attlist
|
|
(insert " ")
|
|
(insert (symbol-name (caar attlist)) "=\"" (cdar attlist) "\"")
|
|
(set 'attlist (cdr attlist)))
|
|
|
|
(insert ">")
|
|
|
|
(set 'tree (xml-node-children tree))
|
|
|
|
;; output the children
|
|
(while tree
|
|
(cond
|
|
((listp (car tree))
|
|
(insert "\n")
|
|
(xml-debug-print-internal (car tree) (concat indent-string " "))
|
|
)
|
|
((stringp (car tree))
|
|
(insert (car tree))
|
|
)
|
|
(t
|
|
(error "Invalid XML tree")))
|
|
(set 'tree (cdr tree))
|
|
)
|
|
|
|
(insert "\n" indent-string
|
|
"</" (symbol-name (xml-node-name xml)) ">")
|
|
))
|
|
|
|
(provide 'xml)
|
|
|
|
;;; xml.el ends here
|