Initial upload. Constant getter is useful to turn constants into methods. This...

Initial upload. Constant getter is useful to turn constants into methods. This is especially useful in order to make certain constants (ex. isIndexable) more dynamic, for example based on runtime or testing environment settings.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@29991 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Accessor/Constant.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2007 Nexedi SA and Contributors. All Rights Reserved.
+#                    Jean-Paul Smets-Solanes <jp@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 Accessor import Accessor
+
+# Creation of default constructor
+class func_code: pass
+
+class Getter(Accessor):
+  """
+  Returns a constant value, either by method call
+  or through type cast (ex. boolean, int, float).
+  This method can be useful to turn existing constant
+  properties of classes into methods, yet retaining 
+  compatibility.
+
+  TODO:
+  - make unit test
+  """
+  _need__name__=1
+
+  # Generic Definition of Method Object
+  # This is required to call the method form the Web
+  # More information at http://www.zope.org/Members/htrd/howto/FunctionTemplate
+  func_code = func_code()
+  func_code.co_varnames = ('self', )
+  func_code.co_argcount = 1
+  func_defaults = ()
+
+  def __init__(self, id, accessor_id, value):
+    self._id = id
+    self.__name__ = id
+    self._accessor_id = accessor_id
+    self.value = value
+
+  def __call__(self, instance):
+    return self.value
+
+  def __nonzero__(self):
+    return bool(self.value)
+
+  def __int__(self):
+    return int(self.value)
+
+  def __float__(self):
+    return float(self.value)