r568@Devoty: necoro | 2007-11-21 15:04:15 +0100

 Yes - we should add session files...

1 files changed, 89 insertions, 0 deletions

diff --git a/portato/session.py b/portato/session.py
new file mode 100644
index 0000000..2a049d1
--- /dev/null
+++ b/portato/session.py
@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+#
+# File: portato/session.py
+# This file is part of the Portato-Project, a graphical portage-frontend.
+#
+# Copyright (C) 2007 René 'Necoro' Neumann
+# This is free software.  You may redistribute copies of it under the terms of
+# the GNU General Public License version 2.
+# There is NO WARRANTY, to the extent permitted by law.
+#
+# Written by René 'Necoro' Neumann <necoro@necoro.net>
+
+from __future__ import absolute_import, with_statement
+
+import os, os.path
+
+from .config_parser import ConfigParser
+from .constants import SESSION_DIR
+from .helper import debug
+
+class Session (object):
+	"""
+	A small class allowing to save certain states of a program.
+	This class works in a quite abstract manner, as it works with handlers, which
+	define what options to use out of the config file and how to apply them to the program.
+
+	Note: This class currently does not work with boolean config options. If you
+	want to define boolean values, use 0 and 1. This is future proof.
+	"""
+
+	def __init__ (self, file):
+		"""
+		Initialize a session with a certain file inside L{SESSION_DIR.}
+
+		@param file: the file in L{SESSION_DIR}, where the options will be saved.
+		"""
+
+		self._cfg = None
+		self._handlers = []
+
+		if not (os.path.exists(SESSION_DIR) and os.path.isdir(SESSION_DIR)):
+			os.mkdir(SESSION_DIR)
+		self._cfg = ConfigParser(os.path.join(SESSION_DIR, file))
+		try:
+			self._cfg.parse()
+		except IOError, e:
+			if e.errno == 2: pass
+			else: raise
+
+	def add_handler (self, (options, load_fn, save_fn)):
+		"""
+		Adds a handler to this session. A handler is a three-tuple consisting of:
+			- a list of (key,section) values
+			- a function getting number of option arguments and applying them to the program
+			- a function returning the number of option return values - getting them out of the program
+		"""
+		self._handlers.append((options, load_fn, save_fn))
+
+	def load (self):
+		"""
+		Loads and applies all values of the session.
+		"""
+		for options, lfn, sfn in self._handlers:
+			try:
+				loaded = [self._cfg.get(*x) for x in options]
+			except KeyError: # does not exist -> ignore
+				debug("No values for %s.", options)
+			else:
+				debug("Loading %s with values %s.", options, loaded)
+				lfn(*loaded)
+
+	def save (self):
+		"""
+		Saves all options into the file.
+		"""
+
+		for options, lfn, sfn in self._handlers:
+			vals = sfn()
+			
+			# map into tuple if necessairy
+			if not hasattr(vals, "__iter__"):
+				vals = (vals,)
+			debug("Saving %s with values %s", options, vals)
+
+			for value, (option, section) in zip(vals, options):
+				self._cfg.add_section(section)
+				self._cfg.add(option, str(value), section = section, with_blankline = False)
+		
+		self._cfg.write()