Hand Application object to Products through ProductContext

Products receive the ProductContext as the first parameter
to their initialize() method when they are loaded. This context used to
contain a reference to the app until it was removed during Zope 4
preparations. The Application was, however, never exposed through an
API.

Access to the API is necessary for certain products that automatically
add objects to the Application when they are loaded, such as the
Products.Sessions and Products.TemporaryFolder. This used to happen in
OFS.Application in Zope 2, but was moved out when the products became
indepentent.

src/App/ProductContext.py

@@ -44,6 +44,7 @@ class ProductContext(object):
 
     def __init__(self, product, app, package):
         self.__prod = product
+        self.__app = app
         self.__pack = package
 
     def registerClass(self, instance_class=None, meta_type='',
@@ -213,6 +214,9 @@ class DummyHelp(object):
             lastRegistered = None
         return DummyHelp()
 
+    def getApplication(self):
+        return self.__app
+
 
 class AttrDict(object):
 

src/OFS/Application.py

@@ -299,7 +299,7 @@ def install_root_view(self):
             self.commit(u'Added default view for root object')
 
     def install_products(self):
-        return install_products()
+        return install_products(self.getApp())
 
     def install_standards(self):
         app = self.getApp()
@@ -424,7 +424,7 @@ def install_product(app, product_dir, product_name, meta_types,
         setattr(Application.misc_, product_name, misc_)
 
     productObject = FactoryDispatcher.Product(product_name)
-    context = ProductContext(productObject, None, product)
+    context = ProductContext(productObject, app, product)
 
     # Look for an 'initialize' method in the product.
     initmethod = pgetattr(product, 'initialize', None)
@@ -439,7 +439,7 @@ def install_package(app, module, init_func, raise_exc=None):
     product.package_name = name
 
     if init_func is not None:
-        newContext = ProductContext(product, None, module)
+        newContext = ProductContext(product, app, module)
         init_func(newContext)
 
     package_initialized(module, init_func)