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

# IVLE - Informatics Virtual Learning Environment

# 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: common.util

# Author: Matt Giuca

# Date: 12/12/2007

# Contains common utility functions.

# Also initialises mime types library. You must import util before using

# Python's builtin mimetypes module to make sure local settings are applied.

import os

import mimetypes

import conf

import conf.mimetypes

root_dir = conf.root_dir

class IVLEError(Exception):

    """

    This is the "standard" exception class for IVLE errors.

    It is the ONLY exception which should propagate to the top - it will then

    be displayed to the user as an HTTP error with the given code.

    All other exceptions are considered IVLE bugs and should not occur

    (they will display a traceback).

    This error should not be raised directly. Call req.throw_error.

    """

    def __init__(self, httpcode, message=None):

        self.httpcode = httpcode

        self.message = message

        self.args = (httpcode, message)

def make_path(path):

    """Given a path relative to the IVLE root, makes the path relative to the

    site root using conf.root_dir. This path can be used in URLs sent to the

    client."""

    return os.path.join(root_dir, path)

def make_local_path(path):

    """Given a path relative to the IVLE root, on the local file system, makes

    the path relative to the root using conf.ivle_install_dir. This path can

    be used in reading files from the local file system."""

    return os.path.join(conf.ivle_install_dir, 'www', path)

def unmake_path(path):

    """Given a path relative to the site root, makes the path relative to the

    IVLE root by removing conf.root_dir if it appears at the beginning. If it

    does not appear at the beginning, returns path unchanged. Also normalises

    the path."""

    path = os.path.normpath(path)

    root = os.path.normpath(root_dir)

    if path.startswith(root):

        path = path[len(root):]

        # Take out the slash as well

        if len(path) > 0 and path[0] == os.sep:

            path = path[1:]

    return path

def split_path(path):

    """Given a path, returns a tuple consisting of the top-level directory in

    the path, and the rest of the path. Note that both items in the tuple will

    NOT begin with a slash, regardless of whether the original path did. Also

    normalises the path.

    Always returns a pair of strings, except for one special case, in which

    the path is completely empty (or just a single slash). In this case the

    return value will be (None, ''). But still always returns a pair.

    Examples:

    >>> split_path("")

    (None, '')

    >>> split_path("/")

    (None, '')

    >>> split_path("home")

    ('home', '')

    >>> split_path("home/docs/files")

    ('home', 'docs/files')

    >>> split_path("//home/docs/files")

    ('', 'home/docs/files')

    """

    path = os.path.normpath(path)

    # Ignore the opening slash

    if path.startswith(os.sep):

        path = path[len(os.sep):]

    if path == '' or path == '.':

        return (None, '')

    splitpath = path.split(os.sep, 1)

    if len(splitpath) == 1:

        return (splitpath[0], '')

    else:

        return tuple(splitpath)

# Initialise mime types library

mimetypes.init()

for (ext, mimetype) in conf.mimetypes.additional_mime_types.items():

    mimetypes.add_type(mimetype, ext)

def nice_filetype(filename):

    """Given a filename or basename, returns a "friendly" name for that

    file's type.

    eg. nice_mimetype("file.py") == "Python source code".

        nice_filetype("file.bzg") == "BZG file".

        nice_filetype("directory/") == "Directory".

    """

    if filename[-1] == os.sep:

        return "Directory"

    else:

        try:

            return conf.mimetypes.nice_mimetypes[

                mimetypes.guess_type(filename)[0]]

        except KeyError:

            filename = os.path.basename(filename)

            try:

                return filename[filename.rindex('.')+1:].upper() + " file"

            except ValueError:

                return "File"