[Zope-CVS] SVN: book/trunk/labyrinth/ Added code for "Spacesuits" chapter.

[Stephan Richter]

Log message for revision 27259:
  Added code for "Spacesuits" chapter.
  


Changed:
  A   book/trunk/labyrinth/
  A   book/trunk/labyrinth/labyrinth.py
  A   book/trunk/labyrinth/labyrinth_security.py


-=-
Added: book/trunk/labyrinth/labyrinth.py
===================================================================
--- book/trunk/labyrinth/labyrinth.py	2004-08-25 14:01:53 UTC (rev 27258)
+++ book/trunk/labyrinth/labyrinth.py	2004-08-25 14:02:26 UTC (rev 27259)
@@ -0,0 +1,85 @@
+##############################################################################
+#
+# Copyright (c) 2004 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+"""Labyrinth Game
+
+This example of Zope 3's security was inspired by the
+zope.security.example. Unfortunately, this code did more than necessary and
+was therefore inappropriate for a book example. This is a much thinner version. 
+
+$Id: labyrinth.py,v 1.1.1.1 2004/02/18 18:07:08 srichter Exp $
+"""
+class Person(object):
+
+    def __init__(self, id):
+        self.id = id
+        self.room = None
+
+    def goTo(self, direction):
+        assert direction in ('north', 'south', 'east', 'west'), \
+               '"%s" is not a valid direction' %direction
+        room = getattr(self.room, direction, None)
+        if room is None:
+            print 'There is no room %s of here.' %direction
+        else:
+            print room.description
+            self.room = room
+        
+
+class Room(object):
+
+    def __init__(self, id, description):
+        self.id = id
+        self.description = description
+        self.north = self.south = self.east = self.west = None
+
+
+def setupWorld():
+    # Create the rooms
+    entrance = Room('entrance', 'The entrance of the labyrinth')
+    fork = Room('fork', 'The big decision. Do I go east or west.')
+    stairs = Room('stairs', 'Some long dark stairs.')
+    hall = Room('hall', 'A cathedral-like hall.')
+    corridor = Room('corridor', 'A long corridor')
+
+    # Connect the rooms
+    entrance.north = fork
+    fork.south, fork.west, fork.east = entrance, stairs, corridor
+    stairs.east, stairs.north = fork, hall
+    corridor.west, corridor.north = fork, hall
+    hall.west, hall.east = stairs, corridor
+
+    # Setup player 
+    player = Person('player')
+    player.room = entrance
+    return player
+
+
+def main():
+    player = setupWorld()
+    command = ''
+    while command != 'exit':
+        try:
+            if command == 'info':
+                print player.room.description
+            elif command:
+                player.goTo(command)
+
+        except Exception, e:
+            print '%s: %s' %(e.__class__.__name__, e)
+
+        command = raw_input('Command: ')
+
+
+if __name__ == '__main__':
+    main()

Added: book/trunk/labyrinth/labyrinth_security.py
===================================================================
--- book/trunk/labyrinth/labyrinth_security.py	2004-08-25 14:01:53 UTC (rev 27258)
+++ book/trunk/labyrinth/labyrinth_security.py	2004-08-25 14:02:26 UTC (rev 27259)
@@ -0,0 +1,83 @@
+##############################################################################
+#
+# Copyright (c) 2004 Zope Corporation and Contributors.
+# All Rights Reserved.
+#
+# This software is subject to the provisions of the Zope Public License,
+# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
+# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
+# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
+# FOR A PARTICULAR PURPOSE.
+#
+##############################################################################
+"""Secure Labyrinth Simulation
+
+This example of Zope 3's security was inspired by the
+zope.security.example. Unfortunately, this code did more than necessary and
+was therefore inappropriate for a book example. This is a much thinner version. 
+
+$Id: labyrinth_security.py,v 1.1.1.1 2004/02/18 18:07:08 srichter Exp $
+"""
+import labyrinth
+from zope.interface import implements
+from zope.security.interfaces import IParticipation
+from zope.security import checker, management, simplepolicies
+
+Allow = 'allow'
+
+permissions = {}
+
+def allowPerson(roomid, personid):
+    """Allow a particular person in a room."""
+    perms = permissions.setdefault(roomid, [])
+    perms.append(personid)
+
+
+class PersonParticipation(object):
+
+    implements(IParticipation)
+
+    def __init__(self, person):
+        self.principal = person
+        self.interaction = None
+
+
+class SecurityPolicy(simplepolicies.ParanoidSecurityPolicy):
+    """The Labyrinth's access security policy."""
+
+    def checkPermission(self, permission, object):
+        """See zope.security.interfaces.ISecurityPolicy"""
+        assert permission is Allow 
+        allowed = permissions.get(object.id, [])
+        for participation in self.participations:
+            if not participation.principal.id in allowed:
+                return False
+        return True
+
+
+def setupSecurity(player):
+    # Setup security
+    management.setSecurityPolicy(SecurityPolicy)
+    room_checker = checker.NamesChecker(
+        ('description', 'north', 'south', 'west', 'east'), Allow)
+    checker.defineChecker(labyrinth.Room, room_checker)
+
+    # Allow the player everywhere but the corridor
+    allowPerson('entrance', player.id)
+    allowPerson('fork', player.id)
+    allowPerson('stairs', player.id)
+    allowPerson('hall', player.id)
+
+    # Add the player as a security manager and provide the player with a
+    # secure room
+    management.newInteraction(PersonParticipation(player))
+    proxied_room = checker.selectChecker(player.room).proxy(player.room)
+    player.room = proxied_room
+    return player
+
+
+if __name__ == '__main__':
+    oldSetupWorld = labyrinth.setupWorld
+    labyrinth.setupWorld = lambda : setupSecurity(oldSetupWorld())
+    labyrinth.main()