do not write -invalid- empty table row when form has no buttons
"""the Bookmark entity type for internal links:organization: Logilab:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses"""classBookmark(MetaUserEntityType):"""bookmarks are used to have user's specific internal links"""title=String(required=True,maxsize=128,internationalizable=True)path=String(maxsize=512,required=True,description=_("relative url of the bookmarked page"))bookmarked_by=SubjectRelation('CWUser',description=_("users using this bookmark"))classbookmarked_by(MetaUserRelationType):permissions={'read':('managers','users','guests',),# test user in users group to avoid granting permission to anonymous user'add':('managers',RRQLExpression('O identity U, U in_group G, G name "users"')),'delete':('managers',RRQLExpression('O identity U, U in_group G, G name "users"')),}