100% coverage; minor whitespace cleanup

Fixes #5

src/zope/viewlet/README.rst

@@ -1,5 +1,6 @@
-Viewlets and Viewlet Managers
-=============================
+===============================
+ Viewlets and Viewlet Managers
+===============================
 
 Let's start with some motivation. Using content providers allows us to insert
 one piece of HTML content. In most Web development, however, you are often
@@ -10,7 +11,7 @@ register content for those regions.
 
 
 Design Notes
-------------
+============
 
 As mentioned above, besides inserting snippets of HTML at places, we more
 frequently want to define a region in our page and allow specialized content
@@ -31,7 +32,7 @@ framework for building pluggable user interfaces.
 
 
 The Viewlet Manager
--------------------
+===================
 
 In this implementation of viewlets, those regions are just content providers
 called viewlet managers that manage a special type of content providers known
@@ -210,7 +211,7 @@ If the viewlet is not found, then the expected behavior is provided:
   True
 
 Customizing the default Viewlet Manager
----------------------------------------
+=======================================
 
 One important feature of any viewlet manager is to be able to filter and sort
 the viewlets it is displaying. The default viewlet manager that we have been
@@ -276,7 +277,7 @@ Of course, we also can remove a shown viewlet:
 
 
 WeightOrderedViewletManager
----------------------------
+===========================
 
 The weight ordered viewlet manager offers ordering viewlets by a additional
 weight argument. Viewlets which doesn't provide a weight attribute will get
@@ -377,7 +378,7 @@ And check the order:
 
 
 ConditionalViewletManager
--------------------------
+=========================
 
 The conditional ordered viewlet manager offers ordering viewlets by a
 additional weight argument and filters by the available attribute if a
@@ -485,7 +486,7 @@ And check the order:
 
 
 Viewlet Base Classes
---------------------
+====================
 
 To make the creation of viewlets simpler, a set of useful base classes and
 helper functions are provided.
@@ -691,10 +692,10 @@ There is also a bundle viewlet for CSS links:
 
 
 A Complex Example
------------------
+=================
 
 The Data
-~~~~~~~~
+--------
 
 So far we have only demonstrated simple (maybe overly trivial) use cases of
 the viewlet system. In the following example, we are going to develop a
@@ -744,7 +745,7 @@ Here is some sample data:
 
 
 The View
-~~~~~~~~
+--------
 
 The contents view of the container should iterate through the container and
 represent the files in a table:
@@ -765,7 +766,7 @@ represent the files in a table:
 
 
 The Viewlet Manager
-~~~~~~~~~~~~~~~~~~~
+-------------------
 
 Now we have to write our own viewlet manager. In this case we cannot use the
 default implementation, since the viewlets will be looked up for each
@@ -845,7 +846,7 @@ Since we have not defined any viewlets yet, the table is totally empty:
 
 
 The Viewlets and the Final Result
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+---------------------------------
 
 Now let's create a first viewlet for the manager...
 
@@ -1025,7 +1026,7 @@ the result will be
 
 
 Supporting Sorting
-~~~~~~~~~~~~~~~~~~
+------------------
 
 Oftentimes you also want to batch and sort the entries in a table. Since those
 two features are not part of the view logic, they should be treated with
@@ -1209,7 +1210,7 @@ room for extending this example:
 
 
 Cleanup
--------
+=======
 
   >>> import shutil
   >>> shutil.rmtree(temp_dir)

src/zope/viewlet/directives.rst

@@ -1,8 +1,9 @@
-Viewlet-related ZCML Directives
-===============================
+=================================
+ Viewlet-related ZCML Directives
+=================================
 
 The ``viewletManager`` Directive
---------------------------------
+================================
 
 The ``viewletManager`` directive allows you to quickly register a new viewlet
 manager without worrying about the details of the ``adapter``
@@ -192,7 +193,7 @@ Finally, if a non-existent template is specified, an error is raised:
 
 
 The ``viewlet`` Directive
--------------------------
+=========================
 
 Now that we have a viewlet manager, we have to register some viewlets for
 it. The ``viewlet`` directive is similar to the ``viewletManager`` directive,
@@ -313,6 +314,32 @@ be rendered upon calling the viewlet:
   >>> viewlet.render()
   u'SRC $5.19'
 
+If the class mentions that it implements any interfaces using the
+old-fashioned style, the resulting viewlet will
+implement ``IBrowserPublisher``:
+
+  >>> from zope.publisher.interfaces.browser import IBrowserPublisher
+  >>> from zope.interface import classImplements
+  >>> Stock.__implements__ = ()
+  >>> context = xmlconfig.string('''
+  ... <configure xmlns="http://namespaces.zope.org/browser" i18n_domain="zope">
+  ...   <viewlet
+  ...       name="stock"
+  ...       for="*"
+  ...       manager="zope.viewlet.directives.ILeftColumn"
+  ...       class="zope.viewlet.directives.Stock"
+  ...       attribute="getStockTicker"
+  ...       permission="zope.Public"
+  ...       />
+  ... </configure>
+  ... ''', context=context)
+
+  >>> viewlet = zope.component.getMultiAdapter(
+  ...     (content, request, view, manager), interfaces.IViewlet,
+  ...     name='stock')
+  >>> IBrowserPublisher.providedBy(viewlet)
+  True
+
 A final feature the ``viewlet`` directive is that it supports the
 specification of any number of keyword arguments:
 
@@ -335,7 +362,7 @@ specification of any number of keyword arguments:
 
 
 Error Scenarios
-~~~~~~~~~~~~~~~
+---------------
 
 Neither the class or template have been specified:
 
@@ -392,8 +419,28 @@ specified attribute:
     ConfigurationError: The provided class doesn't have the specified attribute
 
 
+Now for a template that doesn't exist:
+
+  >>> context = xmlconfig.string('''
+  ... <configure xmlns="http://namespaces.zope.org/browser" i18n_domain="zope">
+  ...   <viewlet
+  ...       name="weather2"
+  ...       for="*"
+  ...       manager="zope.viewlet.directives.ILeftColumn"
+  ...       template="this template is not here"
+  ...       class="zope.viewlet.directives.Weather"
+  ...       permission="zope.Public"
+  ...       />
+  ... </configure>
+  ... ''', context=context)
+  Traceback (most recent call last):
+  ...
+  ZopeXMLConfigurationError: File "<string>", line 3.2-10.8
+    ConfigurationError: ('No such file', '...this template is not here')
+
+
 Cleanup
-~~~~~~~
+-------
 
   >>> import shutil
   >>> shutil.rmtree(temp_dir)

src/zope/viewlet/manager.py

@@ -32,6 +32,7 @@ class ViewletManagerBase(object):
     A generic manager class which can be instantiated
     """
     template = None
+    viewlets = None
 
     def __init__(self, context, request, view):
         self.__updated = False
@@ -49,14 +50,14 @@ def __getitem__(self, name):
         # If the viewlet was not found, then raise a lookup error
         if viewlet is None:
             raise zope.component.interfaces.ComponentLookupError(
-                'No provider with name `%s` found.' %name)
+                'No provider with name `%s` found.' % name)
 
         # If the viewlet cannot be accessed, then raise an
         # unauthorized error
         if not zope.security.canAccess(viewlet, 'render'):
             raise zope.security.interfaces.Unauthorized(
                 'You are not authorized to access the provider '
-                'called `%s`.' %name)
+                'called `%s`.' % name)
 
         # Return the viewlet.
         return viewlet
@@ -102,7 +103,7 @@ def update(self):
         viewlets = self.filter(viewlets)
         viewlets = self.sort(viewlets)
         # Just use the viewlets from now on
-        self.viewlets=[]
+        self.viewlets = []
         for name, viewlet in viewlets:
             if ILocation.providedBy(viewlet):
                 viewlet.__name__ = name
@@ -120,8 +121,7 @@ def render(self):
         # Now render the view
         if self.template:
             return self.template(viewlets=self.viewlets)
-        else:
-            return u'\n'.join([viewlet.render() for viewlet in self.viewlets])
+        return u'\n'.join([viewlet.render() for viewlet in self.viewlets])
 
 
 def ViewletManager(name, interface, template=None, bases=()):
@@ -137,14 +137,14 @@ def ViewletManager(name, interface, template=None, bases=()):
                 interfaces.IViewletManager.implementedBy(bases[0])):
             bases = bases + (ViewletManagerBase,)
 
-    ViewletManager = type(
+    ViewletManagerCls = type(
         '<ViewletManager providing %s>' % interface.getName(), bases, attrDict)
-    zope.interface.classImplements(ViewletManager, interface)
-    return ViewletManager
+    zope.interface.classImplements(ViewletManagerCls, interface)
+    return ViewletManagerCls
 
 
 def getWeight(item):
-    name, viewlet = item
+    _name, viewlet = item
     try:
         return int(viewlet.weight)
     except AttributeError:
@@ -162,10 +162,9 @@ def render(self):
         # do not render a manager template if no viewlets are avaiable
         if not self.viewlets:
             return u''
-        elif self.template:
+        if self.template:
             return self.template(viewlets=self.viewlets)
-        else:
-            return u'\n'.join([viewlet.render() for viewlet in self.viewlets])
+        return u'\n'.join([viewlet.render() for viewlet in self.viewlets])
 
 
 def isAvailable(viewlet):
@@ -185,4 +184,3 @@ def filter(self, viewlets):
         """
         return [(name, viewlet) for name, viewlet in viewlets
                 if isAvailable(viewlet)]
-