We need a view on the content.
>>> request = self.app.REQUEST
>>> from zope.publisher.browser import BrowserView
>>> view = BrowserView(self.portal, request)
>>> from plone.app.layout.viewlets.interfaces import IPortalFooter
>>> from Products.Five.viewlet.manager import ViewletManager
>>> Footer = ViewletManager('left', IPortalFooter)
Now we can instantiate the manager.
>>> manager = Footer(self.portal, request, view)
Set analytics (webstats_js) code through the controlpanel
>>> from plone.registry.interfaces import IRegistry
>>> from zope.component import getUtility
>>> from Products.CMFPlone.interfaces import ISiteSchema
>>> registry = getUtility(IRegistry)
>>> site_settings = registry.forInterface(ISiteSchema, prefix="plone")
>>> site_settings.webstats_js = u""
>>> manager.update()
>>> text = manager.render()
>>> site_settings.webstats_js in text
True
Now enter some non-ascii text
>>> site_settings.webstats_js = u""
>>> manager.update()
>>> text = manager.render()
>>> site_settings.webstats_js in text
True