pykickstart/version.py

   1 #
   2 # Chris Lumens <clumens@redhat.com>
   3 #
   4 # Copyright 2006 Red Hat, Inc.
   5 #
   6 # This software may be freely redistributed under the terms of the GNU
   7 # general public license.
   8 #
   9 # You should have received a copy of the GNU General Public License
  10 # along with this program; if not, write to the Free Software
  11 # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  12 #
  13 """
  14 Methods for working with kickstart versions.
  15
  16 This module defines several symbolic constants that specify kickstart syntax
  17 versions.  Each version corresponds roughly to one release of Red Hat Linux,
  18 Red Hat Enterprise Linux, or Fedora Core as these are where most syntax
  19 changes take place.
  20
  21 This module also exports several functions:
  22
  23     stringToVersion - Convert a string representation of a version number
  24                       into the symbolic constant.
  25
  26     returnClassForVersion - Given a version number, return the matching
  27                             handler class.  This does not return an
  28                             instance of that class, however.
  29
  30     makeVersion - Given a version number, return an instance of the
  31                   matching handler class.
  32 """
  33 from pykickstart.errors import KickstartVersionError
  34
  35 # Symbolic names for internal version numbers.
  36 FC4 = 100
  37 FC5 = 150
  38 FC6 = 200
  39
  40 # This always points at the latest version and is the default.
  41 DEVEL = FC6
  42
  43 def stringToVersion(string):
  44     """Convert string into one of the provided version constants.  Raises
  45        KickstartVersionError if string does not match anything.
  46     """
  47     if string == "FC4":
  48         return FC4
  49     elif string == "FC5":
  50         return FC5
  51     elif string == "FC6":
  52         return FC6
  53     elif string == "DEVEL":
  54         return DEVEL
  55     else:
  56         raise KickstartVersionError(string)
  57
  58 def returnClassForVersion(version):
  59     """Return the class of the syntax handler for version.  version can be
  60        either a string or the matching constant.  Raises KickstartValueError
  61        if version does not match anything.
  62     """
  63     try:
  64         version = int(version)
  65     except ValueError:
  66         version = stringToVersion(version)
  67
  68     if version == FC4:
  69         from pykickstart.commands.fc4 import FC4Version
  70         return FC4Version
  71     elif version == FC5:
  72         from pykickstart.commands.fc5 import FC5Version
  73         return FC5Version
  74     elif version == FC6:
  75         from pykickstart.commands.fc6 import FC6Version
  76         return FC6Version
  77     else:
  78         raise KickstartVersionError(version)
  79
  80 # Given a version of the kickstart syntax, this function imports the correct
  81 # handler for that version and returns an instance of it.
  82 def makeVersion(version=DEVEL):
  83     """Return a new instance of the syntax handler for version.  version can be
  84        either a string or the matching constant.  This function is useful for
  85        standalone programs which just need to handle a specific version of
  86        kickstart syntax (as provided by a command line argument, for example)
  87        and need to instantiate the correct object.
  88     """
  89     super = returnClassForVersion(version)
  90     return super()