Active Record Illustration

post.py

from mongoengine import Document, StringField, ReferenceField, CASCADE, EmbeddedDocumentField, ListField

class Post(Document):
    title = StringField(max_length=120, required=True)
    author = ReferenceField(User, reverse_delete_rule=CASCADE)
    tags = ListField(StringField(max_length=30))
    comments = ListField(EmbeddedDocumentField(Comment))

    meta = {'allow_inheritance': True}

class TextPost(Post):
    content = StringField()

class ImagePost(Post):
    image_path = StringField()

class LinkPost(Post):
    link_url = StringField()

product.py

# Référence : PEAAP, page 162.
# Note : mettre en gras les parties dépendant de la db.
class Product:
    @classmethod
    find(cls, id):
        find_statement = cls.find_statement(id)
        try:
            row = db.findOne(find_statement) # Did you spot the gorilla?
            return cls.load(row)
        except DBException as e:
            # Do what you have to
        finally:
            cls.db.cleanup(find_statement)

    @staticmethod
    load(row):
        # And db deserialization validation?
        return Product(
            id=row[0],
            first_name=row[1],
            last_name=row[2]
        )

user.py

from mongoengine import Document, StringField


class User(Document):
    email = StringField(required=True)
    first_name = StringField(max_length=50)
    last_name = StringField(max_length=50)