=====================
Site view, life cycle
=====================

... or, making the view a site manager is a good idea after
all, but let's see what dangers are lurking in the dark.

Checking if the view finishes its lifetime
------------------------------------------

It is important that the view does not stay on after the
request.  This would cause them to continue listening to
events. We need a few imports first.

  >>> from kss.core.azaxview import SiteView

  >>> from zope.interface import Interface, implements
  >>> from zope.component import adapter
  >>> from zope.lifecycleevent import ObjectModifiedEvent
  >>> from zope.event import notify
  >>> from zope.app.publication.interfaces import IEndRequestEvent
  >>> try:
  ...     from Products.Five.testbrowser import Browser
  ... except ImportError:
  ...     from zope.testbrowser.browser import Browser

First, let's create a funky view that has two methods, one
failing and one succeeding, and a habit to choke on any
events.

  >>> class FunkyView(SiteView):
  ...     def IAmGood(self):
  ...         'XXX'
  ...         return self.render()
  ...     def IAmBad(self):
  ...         'XXX'
  ...         raise Exception, 'Generic badness'
  ...     @adapter(Interface)
  ...     def _eventRedispatcher(self, event):
  ...         SiteView._eventRedispatcher(self, event)
  ...         if not IEndRequestEvent.providedBy(event):
  ...            raise Exception, 'Too late event %r' % event
 
  >>> import kss.core.tests
  >>> kss.core.tests.FunkyView = FunkyView

We provide this view as a browser page. We care to register
it properly, otherwise we would miss some Five acquisition
woodoo. (XXX Note that this must be adjusted to run on Zope3.)

  >>> try:
  ...     import Products.Five
  ... except ImportError:
  ...     # probably zope 3, not supported
  ...     raise 'Zope3 not supported in this test'
  ... else:
  ...     from Products.Five.zcml import load_string, load_config

  >>> load_string('''
  ...      <configure xmlns="http://namespaces.zope.org/zope"
  ...      xmlns:browser="http://namespaces.zope.org/browser"
  ...      xmlns:five="http://namespaces.zope.org/five"
  ...      xmlns:zcml="http://namespaces.zope.org/zcml"
  ...      >
  ...
  ...      <browser:page
  ...          for="*"
  ...          class="kss.core.tests.FunkyView"
  ...          allowed_attributes="IAmGood IAmBad"
  ...          name="funky_view"
  ...          permission="zope.Public"
  ...          />
  ...
  ...  </configure>''')

Create a test browser now, so we can finally start.

  >>> browser = Browser()

Let's call up the good request.

  >>> browser.open(self.folder.absolute_url() + '/@@funky_view/IAmGood')

Now, if we happen to send an event... nothing happens, since
the render() method has taken care of unregistering the
event as a SiteView.

  >>> notify(ObjectModifiedEvent(None))

But it is also important, that even in case the render
method does not run (it gives an error since we raised an
exception, this is all right). We would already get an error
during this, thanks to the RequestEvent that arrives.
  
  >>> browser = browser.open('http://nohost/@@funky_view/IAmBad')
  Traceback (most recent call last):
  ...
  HTTPError: HTTP Error 500: Internal Server Error

And even if we send a new event, it must not get to the
redispatcher of the view.

  >>> notify(ObjectModifiedEvent(None))