use a utility in the view to (artificially) create a place where we d…

…on't have direct access to the request

setup.py

@@ -37,6 +37,7 @@
       extras_require = dict(
           test = [
               'zope.testing',
+              'zope.configuration',
               'zope.app.publisher',
               'zope.app.securitypolicy',
               'zope.testbrowser',

src/zope/globalrequest/README.txt

@@ -21,3 +21,33 @@ Also make sure our test view works:
   >>> browser.contents
   'sif!'
 
+The view tries to query for a utility and use it to "calculate" it's response,
+so let's define one:
+
+  >>> from zope.interface import implements
+  >>> from zope.globalrequest import ftests
+  >>> class Foo(object):
+  ...     implements(ftests.IFoo)
+  ...     def foo(self):
+  ...         return 'foo!'
+
+Unfortunately the utility class cannot be directly imported from here, i.e.
+relatively, so we have to make it available from somewhere else to register
+the utility:
+
+  >>> ftests.Foo = Foo
+  >>> zcml("""
+  ... <configure xmlns="http://namespaces.zope.org/zope">
+  ...   <include package="zope.component" file="meta.zcml" />
+  ...   <utility
+  ...     factory="zope.globalrequest.ftests.Foo"
+  ...     provides="zope.globalrequest.ftests.IFoo" />
+  ... </configure>
+  ... """)
+
+Rendering the view again should now give us the value provided by the utility:
+
+  >>> browser.reload()
+  >>> browser.contents
+  'foo!'
+

src/zope/globalrequest/ftests.py

@@ -1,9 +1,22 @@
 from zope.publisher.browser import BrowserPage
+from zope.interface import Interface
+from zope.component import queryUtility
+
+
+class IFoo(Interface):
+    """ interface for a foo-ish utility """
+
+    def foo():
+        """ return some foo """
 
 
 class FooView(BrowserPage):
    """ a browser view """
 
    def __call__(self, *args, **kw):
-       return 'sif!'
+       foo = queryUtility(IFoo, default=None)
+       if foo is not None:
+           return foo.foo()
+       else:
+           return 'sif!'
 

src/zope/globalrequest/tests.py

@@ -1,10 +1,17 @@
 from unittest import TestSuite
 from zope.testing import doctest
 from zope.testing.cleanup import cleanUp
+from zope.configuration import config
+from zope.configuration import xmlconfig
 from zope.app.testing import functional
 from os.path import join, abspath, dirname
 
 
+def zcml(source):
+    context = config.ConfigurationMachine()
+    xmlconfig.registerCommonDirectives(context)
+    xmlconfig.string(source, context)
+
 def tearDown(test):
     cleanUp()
 
@@ -15,7 +22,8 @@ def tearDown(test):
 def test_suite():
     flags = doctest.NORMALIZE_WHITESPACE | doctest.ELLIPSIS
     readme = functional.FunctionalDocFileSuite('README.txt',
-        package='zope.globalrequest', optionflags=flags, tearDown=tearDown)
+        package='zope.globalrequest', globs={'zcml': zcml},
+        optionflags=flags, tearDown=tearDown)
     readme.layer = testLayer
     return TestSuite((readme,))