#! /usr/bin/python /devel/WWW/2000/10/swap/cwm.py
"""
$Id: converter-cgi.py,v 1.2 2004/11/09 20:00:21 timbl Exp $
convert-cgi
An CGI server applet which provides a form for playing with N3 syntax,
allowing conversion from N3 to conventional RDF.
This is an application which knows a certian amount of stuff and can manipulate it.
It uses llyn, a (forward chaining) query engine, not an (backward chaining) inference engine:
that is, it will apply all rules it can but won't figure out which ones to apply to prove something.
http://www.w3.org/DesignIssues/Notation3
Date: 2000/07/17 21:46:13
Agenda:
=======
"""
import string
import urlparse
# import re
# import StringIO
#import urllib # for log:content
import md5, binascii # for building md5 URIs
urlparse.uses_fragment.append("md5") #@@kludge/patch
urlparse.uses_relative.append("md5") #@@kludge/patch
import notation3 # N3 parsers and generators, and RDF generator
############################################################## Web service
# Author: DanC
#
import random
import time
import cgi
import sys
import StringIO
def serveRequest(env):
import random #for message identifiers. Hmm... should seed from request
#sys.stderr = open("/tmp/connolly-notation3-log", "w")
form = cgi.FieldStorage()
if form.has_key('data'):
try:
convert(form, env)
except BadSyntax, e:
print "Status: 500 syntax error in input data"
print "Content-type: text/plain"
print
print e
except:
import traceback
print "Status: 500 error in python script. traceback follows"
print "Content-type: text/plain"
print
traceback.print_exc(sys.stdout)
else:
showForm()
def convert(form, env):
""" raises KeyError if the form data is missing required fields."""
serviceDomain = 'w3.org' #@@ should compute this from env['SCRIPT_NAME']
# or whatever; cf. CGI spec
thisMessage = 'mid:t%s-r%f@%s' % (time.time(), random.random(), serviceDomain)
data = form['data'].value
if form.has_key('genspace'):
genspace = form['genspace'].value
else: genspace = thisMessage + '#_'
if form.has_key('baseURI'): baseURI = form['baseURI'].value
elif env.has_key('HTTP_REFERER'): baseURI = env['HTTP_REFERER']
else: baseURI = None
# output is buffered so that we only send
# 200 OK if all went well
buf = StringIO.StringIO()
xlate = notation3.ToRDFParser(buf, baseURI, thisMessage, genspace)
xlate.startDoc()
xlate.feed(data)
xlate.endDoc()
print "Content-Type: text/xml"
#hmm... other headers? last-modified?
# handle if-modified-since? i.e. handle input by reference?
print # end of HTTP response headers
print buf.getvalue()
def showForm():
print """Content-Type: text/html
Notation3 to RDF Service
Dan Connolly
"""
############################################################ Main program
if __name__ == '__main__':
import os
# import urlparse
# if os.environ.has_key('SCRIPT_NAME'):
serveRequest(os.environ)
# else:
# doCommand()