modpy module

Synopsis

The modpy module builds upon the classes defined in the cgi module to allow code originally written with the CGI protocol in mind to be used unchanged with the mod_python module.

Usage

See the documentation for the cgi module for information on how to use the CGI abstraction layer. The only difference with the modpy module is that instead of using cgi.Request to call your handler code, you use modpy.Request.

Example:

import jon.cgi as cgi
import jon.modpy as modpy
class Handler(cgi.Handler):
  def process(self, req):
    req.set_header("Content-Type", "text/plain")
    req.write("Hello, world!\n")
def handler(modpy_req):
  return modpy.Request(Handler).process(modpy_req)

Usage with wt

When using modpy with the wt templating system, the Apache setup is slightly different (although all your templates and page code will be identical).

Most of the setup is the same as usual, however the configuration for the /wt/ directory is different. Instead of using a CGI script as the handler, a mod_python handler is used instead:

SetHandler python-program
PythonHandler handler

You then place the code that you would usually put in /cgi-bin/wt.py into /wt/handler.py. The global function handler in this file will be called by mod_python to handle requests, so you should also add this function, which should use wt.Handler or your subclass of it to handle the request:

def handler(modpy_req):
  return modpy.Request(wt.Handler).process(modpy_req)

class: Error(Exception)

The base class for all exceptions defined by the modpy module.

class: Request(cgi.Request)

Request subclasses the cgi.Request class and implements the methods using mod_python's request class.

Public Methods

process(self, modpy_req)

modpy_req: mod_python request instance
Returns: Apache reason code

Initialises the instance ready for a new request by calling the _init method, then reads the user input and sets up the various instance variables. A cgi.Handler object of the type passed to the Request.__init__ method is then instantiated and its process method is called. If an exception is thrown by this method then the traceback method is called to display it.

The value returned by this method is the value that the mod_python handler function should return.

Note that there is a difference in how modpy.Request and cgi.CGIRequest handle the case where the handler outputs a Location header without a hostname. When using the CGI protocol, the Apache web server will issue an internal redirect to handle the new URL. When using mod_python, this is not possible and you should not output Location headers which do not contain absolute URLs.

Example:

def handler(modpy_req):
  return modpy.Request(wt.Handler).process(modpy_req)

class: GZipRequest(GZipMixIn, Request)

For convenience, this class provides the standard Request class with the cgi.GZipMixIn already mixed in.

Example:

def handler(modpy_req):
  return modpy.GZipRequest(wt.Handler).process(modpy_req)

$Id: modpy.html,v 0416d65875b7 2014/03/05 17:37:06 jon $