Remove many_to_one, use more explicit ReferenceCol instead

Mostly because I couldn't get many_to_one to work with Flask-SQLA =/

{{cookiecutter.app_name}}/{{cookiecutter.app_name}}/database.py

@@ -1,41 +1,12 @@
 # -*- coding: utf-8 -*-
-'''Database module, including the SQLAlchemy database object and DB-related
+"""Database module, including the SQLAlchemy database object and DB-related
 utilities.
-'''
+"""
 
 from sqlalchemy.orm import relationship
-from sqlalchemy.ext.declarative import declared_attr
-
 from .extensions import db
 
-# Helpers from Mike Bayer's atmcraft example app
+relationship = relationship
-# https://bitbucket.org/zzzeek/pycon2014_atmcraft/src/a6d96575bc49?at=master
-def many_to_one(clsname, **kw):
-    """Use an event to build a many-to-one relationship on a class.
-
-    This makes use of the :meth:`.References._reference_table` method
-    to generate a full foreign key relationship to the remote table.
-
-    """
-    @declared_attr
-    def m2o(cls):
-        cls._references((cls.__name__, clsname))
-        return relationship(clsname, **kw)
-    return m2o
-
-def one_to_many(clsname, **kw):
-    """Use an event to build a one-to-many relationship on a class.
-
-    This makes use of the :meth:`.References._reference_table` method
-    to generate a full foreign key relationship from the remote table.
-
-    """
-    @declared_attr
-    def o2m(cls):
-        cls._references((clsname, cls.__name__))
-        return relationship(clsname, **kw)
-    return o2m
-
 
 class CRUDMixin(object):
     """Mixin that adds convenience methods for CRUD (create, read, update, delete)
@@ -56,24 +27,31 @@ class CRUDMixin(object):
 
     @classmethod
     def create(cls, **kwargs):
-        '''Create a new record and save it the database.'''
+        """Create a new record and save it the database."""
         instance = cls(**kwargs)
         return instance.save()
 
     def update(self, commit=True, **kwargs):
-        '''Update specific fields of a record.'''
+        """Update specific fields of a record."""
         for attr, value in kwargs.iteritems():
             setattr(self, attr, value)
         return commit and self.save() or self
 
     def save(self, commit=True):
-        '''Save the record.'''
+        """Save the record."""
         db.session.add(self)
         if commit:
             db.session.commit()
         return self
 
     def delete(self, commit=True):
-        '''Remove the record from the database.'''
+        """Remove the record from the database."""
         db.session.delete(self)
         return commit and db.session.commit()
+
+
+def ReferenceCol(tablename, nullable=False, **kwargs):
+    """Column that adds primary key foreign key reference."""
+    return db.Column(
+        db.ForeignKey("{0}.id".format(tablename)),
+        nullable=nullable, **kwargs)

{{cookiecutter.app_name}}/{{cookiecutter.app_name}}/tests/test_models.py

@@ -3,7 +3,7 @@ import unittest
 from nose.tools import *  # PEP8 asserts
 
 from {{ cookiecutter.app_name }}.database import db
-from {{ cookiecutter.app_name }}.user.models import User
+from {{ cookiecutter.app_name }}.user.models import User, Role
 from .base import DbTestCase
 from .factories import UserFactory
 
@@ -29,5 +29,13 @@ class TestUser(DbTestCase):
         user = UserFactory(first_name="Foo", last_name="Bar")
         assert_equal(user.full_name, "Foo Bar")
 
+    def test_roles(self):
+        role = Role(name='admin')
+        role.save()
+        u = UserFactory()
+        u.roles.append(role)
+        u.save()
+        assert_in(role, u.roles)
+
 if __name__ == '__main__':
     unittest.main()

{{cookiecutter.app_name}}/{{cookiecutter.app_name}}/user/models.py

@@ -3,10 +3,21 @@ import datetime as dt
 
 from flask.ext.login import UserMixin
 
-from {{cookiecutter.app_name}}.database import db, CRUDMixin
+from {{cookiecutter.app_name}}.database import (
+    db,
+    CRUDMixin,
+    ReferenceCol,
+    relationship,
+)
 from {{cookiecutter.app_name}}.extensions import bcrypt
 
 
+class Role(CRUDMixin, db.Model):
+    __tablename__ = 'roles'
+    name = db.Column(db.String(80), unique=True, nullable=False)
+    user_id = ReferenceCol('users', nullable=True)
+    user = relationship('User', backref='roles')
+
 class User(UserMixin, CRUDMixin,  db.Model):
 
     __tablename__ = 'users'
@@ -19,6 +30,7 @@ class User(UserMixin, CRUDMixin,  db.Model):
     active = db.Column(db.Boolean())
     is_admin = db.Column(db.Boolean())
 
+
     def __init__(self, username=None, email=None, password=None,
                 first_name=None, last_name=None,
                  active=False, is_admin=False):