Factors items_pending and items_purchased into ItemController

registrasion/controllers/item.py

@@ -0,0 +1,95 @@
+''' NEEDS TESTS '''
+
+from registrasion.models import commerce
+from registrasion.models import inventory
+
+from collections import namedtuple
+from django.db.models import Case
+from django.db.models import Q
+from django.db.models import Sum
+from django.db.models import When
+from django.db.models import Value
+
+_ProductAndQuantity = namedtuple("ProductAndQuantity", ["product", "quantity"])
+
+
+class ProductAndQuantity(_ProductAndQuantity):
+    ''' Class that holds a product and a quantity.
+
+    Attributes:
+        product (models.inventory.Product)
+
+        quantity (int)
+
+    '''
+    pass
+
+
+class ItemController(object):
+
+    def __init__(self, user):
+        self.user = user
+
+    def items_purchased(self, category=None):
+        ''' Aggregates the items that this user has purchased.
+
+        Arguments:
+            category (Optional[models.inventory.Category]): the category
+                of items to restrict to.
+
+        Returns:
+            [ProductAndQuantity, ...]: A list of product-quantity pairs,
+                aggregating like products from across multiple invoices.
+
+        '''
+
+        in_cart = (
+            Q(productitem__cart__user=self.user) &
+            Q(productitem__cart__status=commerce.Cart.STATUS_PAID)
+        )
+
+        quantities_in_cart = When(
+            in_cart,
+            then="productitem__quantity",
+        )
+
+        quantities_or_zero = Case(
+            quantities_in_cart,
+            default=Value(0),
+        )
+
+        products = inventory.Product.objects
+
+        if category:
+            products = products.filter(category=category)
+
+        products = products.select_related("category")
+        products = products.annotate(quantity=Sum(quantities_or_zero))
+        products = products.filter(quantity__gt=0)
+
+        out = []
+        for prod in products:
+            out.append(ProductAndQuantity(prod, prod.quantity))
+        return out
+
+    def items_pending(self):
+        ''' Gets all of the items that the user has reserved, but has not yet
+        paid for.
+
+        Returns:
+            [ProductAndQuantity, ...]: A list of product-quantity pairs for the
+                items that the user has not yet paid for.
+
+        '''
+
+        all_items = commerce.ProductItem.objects.filter(
+            cart__user=self.user,
+            cart__status=commerce.Cart.STATUS_ACTIVE,
+        ).select_related(
+            "product",
+            "product__category",
+        ).order_by(
+            "product__category__order",
+            "product__order",
+        )
+        return all_items

registrasion/templatetags/registrasion_tags.py

@@ -1,31 +1,12 @@
 from registrasion.models import commerce
-from registrasion.models import inventory
 from registrasion.controllers.category import CategoryController
+from registrasion.controllers.item import ItemController
 
-from collections import namedtuple
 from django import template
-from django.db.models import Case
-from django.db.models import Q
 from django.db.models import Sum
-from django.db.models import When
-from django.db.models import Value
 
 register = template.Library()
 
-_ProductAndQuantity = namedtuple("ProductAndQuantity", ["product", "quantity"])
-
-
-class ProductAndQuantity(_ProductAndQuantity):
-    ''' Class that holds a product and a quantity.
-
-    Attributes:
-        product (models.inventory.Product)
-
-        quantity (int)
-
-    '''
-    pass
-
 
 @register.assignment_tag(takes_context=True)
 def available_categories(context):
@@ -67,71 +48,18 @@ def invoices(context):
 
 @register.assignment_tag(takes_context=True)
 def items_pending(context):
-    ''' Gets all of the items that the user has reserved, but has not yet
-    paid for.
-
-    Returns:
-        [ProductAndQuantity, ...]: A list of product-quantity pairs for the
-            items that the user has not yet paid for.
-
-    '''
-
-    all_items = commerce.ProductItem.objects.filter(
-        cart__user=context.request.user,
-        cart__status=commerce.Cart.STATUS_ACTIVE,
-    ).select_related(
-        "product",
-        "product__category",
-    ).order_by(
-        "product__category__order",
-        "product__order",
-    )
-    return all_items
+    ''' Gets all of the items that the user from this context has reserved.'''
+    return ItemController(context.request.user).items_pending()
 
 
 @register.assignment_tag(takes_context=True)
 def items_purchased(context, category=None):
-    ''' Aggregates the items that this user has purchased.
+    ''' Returns the items purchased for this user. '''
 
-    Arguments:
-        category (Optional[models.inventory.Category]): the category of items
-            to restrict to.
-
-    Returns:
-        [ProductAndQuantity, ...]: A list of product-quantity pairs,
-            aggregating like products from across multiple invoices.
-
-    '''
-
-    in_cart = (
-        Q(productitem__cart__user=context.request.user) &
-        Q(productitem__cart__status=commerce.Cart.STATUS_PAID)
+    return ItemController(context.request.user).items_purchased(
+        category=category
     )
 
-    quantities_in_cart = When(
-        in_cart,
-        then="productitem__quantity",
-    )
-
-    quantities_or_zero = Case(
-        quantities_in_cart,
-        default=Value(0),
-    )
-
-    products = inventory.Product.objects
-
-    if category:
-        products = products.filter(category=category)
-
-    products = products.select_related("category")
-    products = products.annotate(quantity=Sum(quantities_or_zero))
-    products = products.filter(quantity__gt=0)
-
-    out = []
-    for prod in products:
-        out.append(ProductAndQuantity(prod, prod.quantity))
-    return out
-
 
 @register.filter
 def multiply(value, arg):