~azzar1/unity/add-show-desktop-key

# IVLE

# Copyright (C) 2007-2008 The University of Melbourne

#

# This program 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 of the License, or

# (at your option) any later version.

#

# This program 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 this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

# Module: dispatch

# Author: Matt Giuca

# Date: 11/12/2007

# This is a mod_python handler program. The correct way to call it is to have

# Apache send all requests to be handled by the module 'dispatch'.

# Top-level handler. Handles all requests to all pages in IVLE.

# Handles authentication (not authorization).

# Then passes the request along to the appropriate ivle app.

import mod_python

from mod_python import apache

import os

import os.path

import conf

import conf.apps

import apps

from request import Request

import html

import login

from common import util

def handler(req):

    """Handles a request which may be to anywhere in the site except media.

    Intended to be called by mod_python, as a handler.

    req: An Apache request object.

    """

    # Make the request object into an IVLE request which can be passed to apps

    apachereq = req

    req = Request(req, html.write_html_head)

    # Check req.app to see if it is valid. 404 if not.

    if req.app is not None and req.app not in conf.apps.app_url:

        # Maybe it is a special app!

        if req.app == 'logout':

            logout(req)

        else:

            # TODO: Nicer 404 message?

            req.throw_error(Request.HTTP_NOT_FOUND)

    # Special handling for public mode - just call public app and get out

    # NOTE: This will not behave correctly if the public app uses

    # write_html_head_foot, but "serve" does not.

    if req.publicmode:

        app = conf.apps.app_url[conf.apps.public_app]

        apps.call_app(app.dir, req)

        return req.OK

    # app is the App object for the chosen app

    if req.app is None:

        app = conf.apps.app_url[conf.apps.default_app]

    else:

        app = conf.apps.app_url[req.app]

    # Check if app requires auth. If so, perform authentication and login.

    if app.requireauth:

        req.username = login.login(req)

        logged_in = req.username is not None

    else:

        req.username = login.get_username(req)

        logged_in = True

    if logged_in:

        # Keep the user's session alive by writing to the session object.

        # req.get_session().save()

        # Well, it's a fine idea, but it creates considerable grief in the

        # concurrent update department, so instead, we'll just make the

        # sessions not time out.

        # If user did not specify an app, HTTP redirect to default app and

        # exit.

        if req.app is None:

            req.throw_redirect(util.make_path(conf.apps.default_app))

        # Set the default title to the app's tab name, if any. Otherwise URL

        # name.

        if app.name is not None:

            req.title = app.name

        else:

            req.title = req.app

        # Call the specified app with the request object

        apps.call_app(app.dir, req)

    # if not logged in, login.login will have written the login box.

    # Just clean up and exit.

    # MAKE SURE we write the HTTP (and possibly HTML) header. This

    # wouldn't happen if nothing else ever got written, so we have to make

    # sure.

    req.ensure_headers_written()

    # When done, write out the HTML footer if the app has requested it

    if req.write_html_head_foot:

        html.write_html_foot(req)

    # Note: Apache will not write custom HTML error messages here.

    # Use req.throw_error to do that.

    return req.OK

def logout(req):

    """Log out the current user (if any) by destroying the session state.

    Then redirect to the top-level IVLE page."""

    session = req.get_session()

    session.invalidate()

    session.delete()

    req.throw_redirect(util.make_path(''))