generic code to create dynamic Python modules

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@38643 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Dynamic/dynamicmodule.py

+from types import ModuleType
+import sys
+
+class DynamicModule(ModuleType):
+    """This module may generate new objects at runtime."""
+    # it's useful to have such a generic utility
+    # please subclass it if you need ERP5-specific behaviors
+
+    def __init__(self, name, factory, doc=None):
+        super(DynamicModule, self).__init__(name, doc=doc)
+        self._factory = factory
+
+    def __getattr__(self, name):
+        if name == '__path__':
+            raise AttributeError('%s does not have __path__' % (self,))
+        obj = self._factory(name)
+        if hasattr(obj, '__module__'):
+            obj.__module__ = self.__name__
+        setattr(self, name, obj)
+        return obj
+
+def dynamicmodule(name, factory):
+    d = DynamicModule(name, factory)
+    sys.modules[name] = d
+    return d