from google.appengine.ext import db

class Article(db.Model):
    title      = db.StringProperty()
    body       = db.TextProperty()
    published  = db.DateTimeProperty(auto_now = True)
    tag_names = db.ListProperty(db.Key)

    @property
    def tags(self):
        tags = []
        for tag_key in self.tag_names:
            tags.append(db.get(tag_key).name)
        return tags
    
class Tag(db.Model):
    name = db.StringProperty()
    @property
    def members(self):
        return Article.gql('WHERE tags = :1', self.key())