1 ;;;; -*- mode: lisp -*-
 2 ;;;;
 3 ;;;; $Id: tracer.lisp,v 1.2 2004/06/11 11:14:43 scaekenberghe Exp $
 4 ;;;;
 5 ;;;; A simple SSAX tracer example that can be used to understand how the hooks are called
 6 ;;;;
 7 ;;;; Copyright (C) 2004 Sven Van Caekenberghe, Beta Nine BVBA.
 8 ;;;;
 9 ;;;; You are granted the rights to distribute and use this software
10 ;;;; as governed by the terms of the Lisp Lesser General Public License
11 ;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
12 
13 (in-package :s-xml)
14 
15 (defun trace-xml-log (level msg &rest args)
16   (indent *standard-output* level)
17   (apply #'format *standard-output* msg args)
18   (terpri *standard-output*))
19 
20 (defun trace-xml-new-element-hook (name attributes seed)
21   (let ((new-seed (cons (1+ (car seed)) (1+ (cdr seed)))))
22     (trace-xml-log (car seed) 
23                    "(new-element :name ~s :attributes ~:[()~;~:*~s~] :seed ~s) => ~s" 
24                    name attributes seed new-seed)
25     new-seed))
26 
27 (defun trace-xml-finish-element-hook (name attributes parent-seed seed)
28   (let ((new-seed (cons (1- (car seed)) (1+ (cdr seed)))))
29     (trace-xml-log (car parent-seed)
30                    "(finish-element :name ~s :attributes ~:[()~;~:*~s~] :parent-seed ~s :seed ~s) => ~s" 
31                    name attributes parent-seed seed new-seed)
32     new-seed))
33 
34 (defun trace-xml-text-hook (string seed)
35   (let ((new-seed (cons (car seed) (1+ (cdr seed)))))
36     (trace-xml-log (car seed) 
37                    "(text :string ~s :seed ~s) => ~s" 
38                    string seed new-seed)
39     new-seed))
40 
41 (defun trace-xml (in)
42   "Parse and trace a toplevel XML element from stream in"
43   (start-parse-xml in
44 		   (make-instance 'xml-parser-state
45 				  :seed (cons 0 0) 
46                                   ;; seed car is xml element nesting level
47                                   ;; seed cdr is ever increasing from element to element
48 				  :new-element-hook #'trace-xml-new-element-hook
49                                   :finish-element-hook #'trace-xml-finish-element-hook
50 				  :text-hook #'trace-xml-text-hook)))
51 
52 (defun trace-xml-file (pathname)
53   "Parse and trace XMl from the file at pathname"
54   (with-open-file (in pathname)
55     (trace-xml in)))
56 
57 ;;;; eof