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

# IVLE - Informatics Virtual Learning Environment

# Copyright (C) 2009 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

# Author: William Grant

'''Media file support for the framework.'''

import os

import inspect

import mimetypes

import ivle.conf

from ivle.webapp.base.views import BaseView

from ivle.webapp.base.plugins import ViewPlugin

from ivle.webapp.errors import NotFound

def media_url(req, plugin, path):

    '''Generates a URL to a media file.

    Plugin can be a string, in which case it is put into the path literally,

    or a plugin object, in which case its name is looked up.'''

    if not isinstance(plugin, basestring):

        plugin = req.reverse_plugins[plugin]

    return os.path.join(ivle.conf.root_dir, '+media', plugin, path)

class MediaFileView(BaseView):

    '''A view for media files.

    This serves static files from directories registered by plugins.

    Plugins wishing to export media should declare a 'media' attribute,

    pointing to the directory to serve (relative to the module's directory).

    The contents of that directory will then be available under

    /+media/python.path.to.module.

    '''

    def __init__(self, req, ns, path):

        self.ns = ns

        self.path = path

    def _make_filename(self, req):

        try:

            plugin = req.plugins[self.ns]

        except KeyError:

            raise NotFound()

        try:

            mediadir = plugin.media

        except AttributeError:

            raise NotFound()

        plugindir = os.path.dirname(inspect.getmodule(plugin).__file__)

        return os.path.join(plugindir, mediadir, self.path)

    def render(self, req):

        # If it begins with ".." or separator, it's illegal. Die.

        if self.path.startswith("..") or self.path.startswith('/'):

            raise Forbidden()

        filename = self._make_filename(req)

        # Find an appropriate MIME type.

        (type, _) = mimetypes.guess_type(filename)

        if type is None:

            type = 'application/octet-stream'

        # Get out if it is unreadable or a directory.

        if not os.access(filename, os.F_OK):

            raise NotFound()

        if not os.access(filename, os.R_OK) or os.path.isdir(filename):

            raise Forbidden()

        req.content_type = type

        req.sendfile(filename)

class Plugin(ViewPlugin):

    urls = [

        ('+media/:ns/*path', MediaFileView),

    ]