#213 paginated products

catalog/newcontext/__init__.py

@@ -1,3 +1,4 @@
-# @todo #207:120m Implement Page, PaginatedProducts context classes.
+# @todo #207:60m Implement Page context class.
+
 from . import products, tags
 from .context import Context, Contexts, ModelContext, Products, Tags

catalog/newcontext/products.py

@@ -1,10 +1,13 @@
 import typing
+from functools import lru_cache
 
+from django import http
 from django.conf import settings
 from django.db.models import QuerySet
 
 from catalog.newcontext.context import Context, Products, Tags
 from catalog.models import AbstractCategory
+from refarm_pagination.context import PaginationContext
 
 
 class SortingOption:
@@ -30,9 +33,9 @@ def qs(self):
 
 class OrderedProducts(Products):
 
-    def __init__(self, products: Products, req_kwargs):
+    def __init__(self, products: Products, sorting_index=0):
         self._products = products
-        self._sorting_index = req_kwargs.get('sorting', 0)
+        self._sorting_index = sorting_index
 
     def qs(self):
         return self._products.qs().order_by(
@@ -86,6 +89,7 @@ def context(self):
         }
 
         return {
+            **self._products.context(),
             'product_brands': product_brands,
         }
 
@@ -108,5 +112,34 @@ def context(self):
         }
 
         return {
+            **self._products.context(),
             'product_images': product_images,
         }
+
+
+class PaginatedProducts(Products):
+    """Slice products and add pagination data to a context."""
+
+    def __init__(self, products: Products, url: str, page_number: int, per_page: int):
+        if (
+            page_number < 1 or
+            per_page not in settings.CATEGORY_STEP_MULTIPLIERS
+        ):
+            raise http.Http404('Page does not exist.')
+
+        self._products = products
+        self._page_number = page_number
+        self._pagination = PaginationContext(url, page_number, per_page, self._products.qs())
+
+    @lru_cache()
+    def _pagination_context(self):
+        return self._pagination.context()
+
+    def qs(self):
+        return self._pagination_context()['page'].object_list
+
+    def context(self):
+        return {
+            **self._products.context(),
+            'paginated': self._pagination_context(),
+        }

catalog/newcontext/tags.py

@@ -17,9 +17,9 @@ def context(self):
 
 class ParsedTags(Tags):
 
-    def __init__(self, tags: Tags, req_kwargs):
+    def __init__(self, tags: Tags, raw_tags=''):
         self._tags = tags
-        self._raw_tags = req_kwargs.get('tags')
+        self._raw_tags = raw_tags
 
     def qs(self):
         tags = self._tags.qs()

tests/catalog/test_context.py

@@ -1,3 +1,8 @@
+"""
+@todo #213:30m Remove mocked Context classes.
+ Wait for fixtures of Tag models to implement this.
+"""
+
 import unittest
 
 from django.test import TestCase, override_settings
@@ -18,6 +23,7 @@ def mocked_ctx(qs_attrs=None, context_attrs=None):
 class ProductsContext(TestCase):
 
     fixtures = ['catalog.json']
+    per_page = 30
 
     def products_ctx(self, qs=None) -> context.context.Products:
         return context.context.Products(qs or catalog_models.MockProduct.objects.all())
@@ -30,9 +36,30 @@ def test_ordered_products(self):
             products_ctx = self.products_ctx()
             self.assertEqual(
                 list(products_ctx.qs().order_by(order_by)),
-                list(context.products.OrderedProducts(products_ctx, {'sorting': 1}).qs()),
+                list(context.products.OrderedProducts(products_ctx, 1).qs()),
+            )
+
+    def test_paginated_qs(self):
+        with override_settings(CATEGORY_STEP_MULTIPLIERS=[self.per_page]):
+            products = self.products_ctx()
+            self.assertEqual(
+                list(products.qs()[:self.per_page]),
+                list(context.products.PaginatedProducts(
+                    products, '', 1, self.per_page,
+                ).qs()),
             )
 
+    def test_paginated_404(self):
+        page_number = 1
+        with override_settings(CATEGORY_STEP_MULTIPLIERS=[self.per_page]):
+            with self.assertRaises(Http404):
+                # per_page not in CATEGORY_STEP_MULTIPLIERS
+                context.products.PaginatedProducts(None, '', page_number, self.per_page-1)
+
+            with self.assertRaises(Http404):
+                # page number doesn't exist
+                context.products.PaginatedProducts(None, '', page_number-1, self.per_page)
+
     def test_tagged_products(self):
         products_ctx = mocked_ctx()
         context.products.TaggedProducts(
@@ -55,13 +82,13 @@ class TagsContext(TestCase):
 
     def test_parsed_tags(self):
         tags_ctx = mocked_ctx()
-        context.tags.ParsedTags(tags_ctx, {'tags': 'test'}).qs()
+        context.tags.ParsedTags(tags_ctx, raw_tags='test1=test2').qs()
         self.assertTrue(tags_ctx.qs().parsed.called)
 
     def test_unparsed_tags(self):
         self.assertFalse(
             context.tags.ParsedTags(
-                mocked_ctx(qs_attrs={'none.return_value': []}), {},
+                mocked_ctx(qs_attrs={'none.return_value': []}), '',
             ).qs()
         )
 

tests/refarm_pagination/test_views.py → tests/refarm_pagination/test_context.py

@@ -3,17 +3,17 @@
 
 from django.conf import settings
 from django.test import TestCase
-from refarm_pagination import views, pagination
+from refarm_pagination.context import PaginationContext
 
 from tests.catalog.models import MockProduct
 
 
-class PaginationContext(TestCase):
+class TestPaginationContext(TestCase):
 
     fixtures = ['catalog.json']
 
     def context(self, **kwargs):
-        return views.PaginationContext(**{
+        return PaginationContext(**{
             'url': '',
             'number': 1,
             'per_page': 1,
@@ -23,7 +23,7 @@ def context(self, **kwargs):
 
     @contextmanager
     def mock_neighbor_pairs(self, url, number):
-        with mock.patch('refarm_pagination.views.NeighborPages') as mocked_pages:
+        with mock.patch('refarm_pagination.context.NeighborPages') as mocked_pages:
             mocked_page = mock.Mock()
             mocked_page.url = lambda _: url
             mocked_page.number = number