[Zope-CVS] CVS: Products/ZopeVersionControl - Version.py:1.2

[Brian Lloyd]

Update of /cvs-repository/Products/ZopeVersionControl
In directory cvs.zope.org:/tmp/cvs-serv8983

Modified Files:
	Version.py 
Log Message:
implement quick-hack of read-only protection for version data

=== Products/ZopeVersionControl/Version.py 1.1 => 1.2 ===
         return self.records
 
+    def getReadOnlyObject(self):
+        """Return the object corresponding to this version."""
+        object = Acquisition.aq_base(self.data)
+        object._p_jar = ReadOnlyJar(object._p_jar)
+        return object
+
     def saveState(self, object):
         baseobj = Acquisition.aq_base(object)
         # xxx - fix this!
@@ -107,4 +113,41 @@
         return self.id
 
 InitializeClass(Version)
+
+
+
+
+def historicalRevision(self, serial):
+    state=self._p_jar.oldstate(self, serial)
+    rev=self.__class__.__basicnew__()
+    rev._p_jar=HystoryJar(self._p_jar)
+    rev._p_oid=self._p_oid
+    rev._p_serial=serial
+    rev.__setstate__(state)
+    rev._p_changed=0
+    return rev
+
+
+class ReadOnlyJar:
+    """A read-only ZODB connection-like object that prevents changes."""
+
+    def __init__(self, base):
+        self.__base__=base
+
+    _invalidating = []
+
+    def __getattr__(self, name):
+        return getattr(self.__base__, name)
+
+    def commit(*args, **kw):
+        raise VersionWriteError(
+            'Old versions of objects cannot be modified.'
+            )
+
+    def abort(*args, **kw):
+        pass
+
+
+class VersionWriteError(Exception):
+    pass