""" Minimal CGI publisher --- Magnus Lie Hetland, 1999

    Usage:
    In a python script running as a cgi-program, import the publish-
    function:
   
      from MinimalCGIPublisher import publish
   
    And at the end of the script, call the publish() function.
   
    Arguments:
   
    - function: Optional argument showing which function will be called if
      none is present in the URL (see below)
   
    - arglist: Positional parameters (strings) restricting which arguments
      from the URL will be passed on.
   
    - named: Named parameters. Only the parameter "type" is used, if
      present. It gives the MIME type of the result string from the
      published function. (All published functions should return a
      string, representing the resulting document.)
   
    If the module "egg.cgi" with the method "ni" is published at www.spam.org
    it can be called like this:
   
      http://www.spam.org/egg.cgi
   
    If no method was given in the call to publish(), we could call it like
    this:
   
      http://www.spam.org/egg.cgi/ni
   
    Named parameters could be added thus:
   
      http://www.spam.org/egg.cgi/ni?x=1&y=2
   
    If more arguments are given than the function expects, and no arglist
    is given in the call to publish(), an exception will occur. In that case
    a minimal error page will be displayed.
"""

import cgi, os

def publish(function=None,*arglist,**named):
    params = cgi.FieldStorage()
    paramdict = {}
    for key in params.keys():
        if not arglist or key in arglist:
            paramdict[key] = params[key].value
    if os.environ.has_key('PATH_INFO'):
        import __main__
        function = getattr(__main__,os.environ['PATH_INFO'][1:])
    try:
        result = apply(function, (), paramdict)
    except:
        print "Content-type: text/html\n"
        print "<h1>An exception occured</h1><pre>"
        import sys, traceback
        sys.stderr = sys.stdout
        traceback.print_exc()
    else:
        type = named.has_key("type") and named["type"] or "text/html"
        print "Content-type: %s\n" % type
        print str(result)