schema.py

from yams.buildobjs import EntityType, RelationType, String, Boolean, RichString
_ = unicode

class Link(EntityType):
    """a link to an external internet resource"""
    title = String(required=True, fulltextindexed=True, maxsize=256)
    url = String(required=True, fulltextindexed=True, maxsize=512,
                 description=_("link's url"))
    description = RichString(fulltextindexed=True,
                         description=_("description of the linked page's content"))