Add base_convertable mixin which follows base_convertable interface

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@35212 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/mixin/base_convertable.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2010 Nexedi SA and Contributors. All Rights Reserved.
+#                    Nicolas Delaby <nicolas@nexedi.com>
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsability of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# garantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+##############################################################################
+from Products.ERP5Type.Base import WorkflowMethod
+from AccessControl import ClassSecurityInfo
+from Products.ERP5Type import Permissions
+
+class BaseConvertableMixin:
+  """
+  This class provides a generic implementation of IBaseConvertable.
+  """
+
+  security = ClassSecurityInfo()
+
+  security.declareProtected(Permissions.ModifyPortalContent, 'convertToBaseFormat')
+  def convertToBaseFormat(self):
+    """
+    """
+    if not self.hasData():
+      # Empty document cannot be converted
+      return
+    try:
+      message = self._convertToBaseFormat() # Call implemetation method
+      if message is None:
+        message = self.Base_translateString('Converted to ${mime_type}.',
+                              mapping={'mime_type': self.getBaseContentType()})
+      self.convertFile(comment=message) # Invoke workflow method
+    except NotImplementedError:
+      message = ''
+    return message
+
+  security.declareProtected(Permissions.ModifyPortalContent, 'updateBaseMetadata')
+  def updateBaseMetadata(self, **kw):
+    """
+    """
+    raise NotImplementedError