Add new base classes for customer order/item models

so that we can batch things out next

rattail/db/model/__init__.py

@@ -49,7 +49,8 @@ from .products import (Brand, Tax, Product, ProductImage, ProductCode,
 from .purchase import (PurchaseBase, PurchaseItemBase, PurchaseCreditBase,
                        Purchase, PurchaseItem, PurchaseCredit)
 
-from .custorders import CustomerOrder, CustomerOrderItem, CustomerOrderItemEvent
+from .custorders import (CustomerOrderBase, CustomerOrderItemBase,
+                         CustomerOrder, CustomerOrderItem, CustomerOrderItemEvent)
 
 from .messages import Message, MessageRecipient
 

rattail/db/model/custorders.py

@@ -1,8 +1,8 @@
-# -*- coding: utf-8 -*-
+# -*- coding: utf-8; -*-
 ################################################################################
 #
 #  Rattail -- Retail Software Framework
-#  Copyright © 2010-2017 Lance Edgar
+#  Copyright © 2010-2020 Lance Edgar
 #
 #  This file is part of Rattail.
 #
@@ -32,21 +32,63 @@ import six
 import sqlalchemy as sa
 from sqlalchemy import orm
 from sqlalchemy.ext.orderinglist import ordering_list
+from sqlalchemy.ext.declarative import declared_attr
 
 from rattail.db.model import Base, uuid_column
 from rattail.db.model import Customer, Person, Product, User
 
 
 @six.python_2_unicode_compatible
-class CustomerOrder(Base):
+class CustomerOrderBase(object):
+    """
+    Base class for customer orders; defines common fields.
+    """
+
+    @declared_attr
+    def __table_args__(cls):
+        return cls.__customer_order_table_args__()
+
+    @classmethod
+    def __customer_order_table_args__(cls):
+        table_name = cls.__tablename__
+        return (
+            sa.ForeignKeyConstraint(['customer_uuid'], ['customer.uuid'],
+                                    name='{}_fk_customer'.format(table_name)),
+            sa.ForeignKeyConstraint(['person_uuid'], ['person.uuid'],
+                                    name='{}_fk_person'.format(table_name)),
+        )
+
+    customer_uuid = sa.Column(sa.String(length=32), nullable=True)
+
+    @declared_attr
+    def customer(cls):
+        return orm.relationship(
+            Customer,
+            doc="""
+            Reference to the customer account for which the order exists.
+            """)
+
+    person_uuid = sa.Column(sa.String(length=32), nullable=True)
+
+    @declared_attr
+    def person(cls):
+        return orm.relationship(
+            Person,
+            doc="""
+            Reference to the person to whom the order applies.
+            """)
+
+    created = sa.Column(sa.DateTime(), nullable=False, default=datetime.datetime.utcnow, doc="""
+    Date and time when the order/batch was first created.
+    """)
+
+
+@six.python_2_unicode_compatible
+class CustomerOrder(CustomerOrderBase, Base):
     """
     Represents an order placed by the customer.
     """
     __tablename__ = 'custorder'
-    __table_args__ = (
-        sa.ForeignKeyConstraint(['customer_uuid'], ['customer.uuid'], name='custorder_fk_customer'),
-        sa.ForeignKeyConstraint(['person_uuid'], ['person.uuid'], name='custorder_fk_person'),
-    )
 
     uuid = uuid_column()
 
@@ -54,22 +96,6 @@ class CustomerOrder(Base):
     Numeric, auto-increment ID for the order.
     """)
 
-    customer_uuid = sa.Column(sa.String(length=32), nullable=True)
-
-    customer = orm.relationship(Customer, doc="""
-    Reference to the :class:`Customer` instance for whom the order exists.
-    """)
-
-    person_uuid = sa.Column(sa.String(length=32), nullable=True)
-
-    person = orm.relationship(Person, doc="""
-    Reference to the :class:`Person` instance for whom the order exists.
-    """)
-
-    created = sa.Column(sa.DateTime(), nullable=False, default=datetime.datetime.utcnow, doc="""
-    Date and time when the order was first created.
-    """)
-
     status_code = sa.Column(sa.Integer(), nullable=False)
 
     items = orm.relationship('CustomerOrderItem', back_populates='order',
@@ -84,24 +110,23 @@ class CustomerOrder(Base):
 
 
 @six.python_2_unicode_compatible
-class CustomerOrderItem(Base):
+class CustomerOrderItemBase(object):
     """
-    Represents a particular line item (product) within a customer order.
+    Base class for customer order line items.
     """
-    __tablename__ = 'custorder_item'
-    __table_args__ = (
-        sa.ForeignKeyConstraint(['order_uuid'], ['custorder.uuid'], name='custorder_item_fk_order'),
-        sa.ForeignKeyConstraint(['product_uuid'], ['product.uuid'], name='custorder_item_fk_product'),
+
+    @declared_attr
+    def __table_args__(cls):
+        return cls.__customer_order_item_table_args__()
+
+    @classmethod
+    def __customer_order_item_table_args__(cls):
+        table_name = cls.__tablename__
+        return (
+            sa.ForeignKeyConstraint(['product_uuid'], ['product.uuid'],
+                                    name='{}_fk_product'.format(table_name)),
         )
 
-    uuid = uuid_column()
-
-    order_uuid = sa.Column(sa.String(length=32), nullable=False)
-
-    order = orm.relationship(CustomerOrder, back_populates='items', doc="""
-    Reference to the :class:`CustomerOrder` instance to which the item belongs.
-    """)
-
     sequence = sa.Column(sa.Integer(), nullable=False, doc="""
     Numeric sequence for the item, i.e. its "line number".  These values should
     obviously increment in sequence and be unique within the context of a
@@ -110,8 +135,12 @@ class CustomerOrderItem(Base):
 
     product_uuid = sa.Column(sa.String(length=32), nullable=True)
 
-    product = orm.relationship(Product, doc="""
-    Reference to the :class:`Product` instance for the item.
+    @declared_attr
+    def product(cls):
+        return orm.relationship(
+            Product,
+            doc="""
+            Reference to the master product record for the line item.
             """)
 
     product_brand = sa.Column(sa.String(length=100), nullable=True, doc="""
@@ -184,11 +213,32 @@ class CustomerOrderItem(Base):
     Transaction number in which payment for the order was taken, if applicable.
     """)
 
-    status_code = sa.Column(sa.Integer(), nullable=False)
-
-    # TODO
     def __str__(self):
-        return str(self.product)
+        return str(self.product or "(no product)")
+
+
+@six.python_2_unicode_compatible
+class CustomerOrderItem(CustomerOrderItemBase, Base):
+    """
+    Represents a particular line item (product) within a customer order.
+    """
+    __tablename__ = 'custorder_item'
+
+    @declared_attr
+    def __table_args__(cls):
+        return cls.__customer_order_item_table_args__() + (
+            sa.ForeignKeyConstraint(['order_uuid'], ['custorder.uuid'],
+                                    name='custorder_item_fk_order'),
+        )
+
+    uuid = uuid_column()
+
+    order_uuid = sa.Column(sa.String(length=32), nullable=False)
+    order = orm.relationship(CustomerOrder, back_populates='items', doc="""
+    Reference to the :class:`CustomerOrder` instance to which the item belongs.
+    """)
+
+    status_code = sa.Column(sa.Integer(), nullable=False)
 
 
 class CustomerOrderItemEvent(Base):