from Acquisition import aq_base

def install(self):
    portal = self.portal_url.getPortalObject()
    # Set default icon.
    portal.manage_addProperty('logo', 'logo.png', 'string')
    if self._language == 'en':
        portal.manage_addProperty('homepage_message', 'Welcome', 'text')
    elif self._language == 'no':
        portal.manage_addProperty('homepage_message', 'Velkommen', 'text')
    else:
        raise AssertionError("Not a supported language.")
    
    folder = self.portal_membership.getMembersFolder()
    index_html = getattr(aq_base(folder), 'index_html', None)
    if index_html is None:
        folder.manage_addProduct['OFSP'].methodAdd(id='index_html')
        index_html = getattr(aq_base(folder), 'index_html')
    
    index_html.text = "<dtml-var homepage>"
    index_html.raw  = "<dtml-var homepage>"