implement cross_selling_visibility "always" and "products"

src/pretix/presale/checkoutflow.py

@@ -93,7 +93,7 @@ from pretix.presale.views import (
     CartMixin, get_cart, get_cart_is_free, get_cart_total,
 )
 from pretix.presale.views.cart import (
-    cart_session, create_empty_cart_id, get_or_create_cart_id,
+    cart_session, create_empty_cart_id, get_or_create_cart_id, _items_from_post_data,
 )
 from pretix.presale.views.event import get_grouped_items
 from pretix.presale.views.questions import QuestionsViewMixin
@@ -488,9 +488,17 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
 
     def is_applicable(self, request):
         if not hasattr(request, '_checkoutflow_addons_applicable'):
-            request._checkoutflow_addons_applicable = get_cart(request).filter(item__addons__isnull=False).exists()
+            cart = get_cart(request)
+            self.request = request
+            request._checkoutflow_addons_applicable = (cart.filter(item__addons__isnull=False).exists()
+               or any(self.cross_selling_applicable_rules))
         return request._checkoutflow_addons_applicable
 
+    @cached_property
+    def cross_selling_applicable_rules(self):
+        cart = self.get_cart(self.request)
+        return [c for c in self.request.event.categories.filter(cross_selling_mode__isnull=False) if c.cross_sell_visible(cart['positions'])]
+
     def is_completed(self, request, warn=False):
         if getattr(self, '_completed', None) is not None:
             return self._completed
@@ -605,9 +613,48 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
                 formset.append(formsetentry)
         return formset
 
+    def get_cross_selling_data(self, ctx):
+        class DummyCategory:
+            def __init__(self, rule, subevent=None):
+                self.id = rule.id
+                self.name = rule.name + (f" ({subevent})" if subevent else "")
+                self.description = rule.description
+
+        if self.event.has_subevents:
+            return [
+                (DummyCategory(rule, subevent), self._items_from_rule(rule, subevent), f'subevent_{subevent.pk}_')
+                for rule in self.cross_selling_applicable_rules
+                for subevent in set(pos.subevent for pos in ctx['cart']['positions'])
+            ]
+        else:
+            return [
+                (rule, self._items_from_rule(rule, None))
+                for rule in self.cross_selling_applicable_rules
+            ]
+
+    def _items_from_rule(self, rule, subevent):
+        items, _btn = get_grouped_items(
+            self.request.event,
+            subevent=subevent,
+            voucher=None,
+            channel=self.request.sales_channel.identifier,
+            base_qs=rule.items.all(),
+            allow_addons=True,
+            allow_cross_sell=True,
+            memberships=(
+                self.request.customer.usable_memberships(
+                    for_event=self.request.event,  #p.subevent or self.request.event,
+                    testmode=self.request.event.testmode
+                )
+                if self.request.customer else None
+            ),
+        )
+        return items
+
     def get_context_data(self, **kwargs):
         ctx = super().get_context_data(**kwargs)
         ctx['forms'] = self.forms
+        ctx['cross_selling_data'] = self.get_cross_selling_data(ctx)
         ctx['cart'] = self.get_cart()
         return ctx
 
@@ -687,7 +734,7 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
 
     def post(self, request, *args, **kwargs):
         self.request = request
-        data = []
+        addons = []
         for f in self.forms:
             for c in f['categories']:
                 try:
@@ -697,7 +744,7 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
                     return self.get(request, *args, **kwargs)
 
                 for (i, v), (c, price) in selected.items():
-                    data.append({
+                    addons.append({
                         'addon_to': f['pos'].pk,
                         'item': i.pk,
                         'variation': v.pk if v else None,
@@ -705,7 +752,9 @@ class AddOnsStep(CartMixin, AsyncAction, TemplateFlowStep):
                         'price': price,
                     })
 
-        return self.do(self.request.event.id, data, get_or_create_cart_id(self.request),
+        add_to_cart_items = _items_from_post_data(self.request)
+
+        return self.do(self.request.event.id, addons, add_to_cart_items, get_or_create_cart_id(self.request),
                        invoice_address=self.invoice_address.pk, locale=get_language(),
                        sales_channel=request.sales_channel.identifier, override_now_dt=time_machine_now(default=None))
 

src/pretix/presale/templates/pretixpresale/event/checkout_addons.html

@@ -46,6 +46,9 @@
                 </details>
             {% endfor %}
         </div>
+
+        {% include "pretixpresale/event/fragment_product_list.html" with items_by_category=cross_selling_data ev=event %}
+
         <div class="row checkout-button-row">
             <div class="col-md-4 col-sm-6">
                 <a class="btn btn-block btn-default btn-lg"

src/pretix/presale/views/cart.py

@@ -151,112 +151,113 @@ class CartActionMixin:
         except InvoiceAddress.DoesNotExist:
             return InvoiceAddress()
 
-    def _item_from_post_value(self, key, value, voucher=None, voucher_ignore_if_redeemed=False):
-        if value.strip() == '' or '_' not in key:
-            return
 
-        subevent = None
-        if key.startswith('subevent_'):
-            try:
-                parts = key.split('_', 2)
-                subevent = int(parts[1])
-                key = parts[2]
-            except ValueError:
-                pass
-        elif 'subevent' in self.request.POST:
-            try:
-                subevent = int(self.request.POST.get('subevent'))
-            except ValueError:
-                pass
-
-        if not key.startswith('item_') and not key.startswith('variation_') and not key.startswith('seat_'):
-            return
-
-        parts = key.split("_")
-        price = self.request.POST.get('price_' + "_".join(parts[1:]), "")
-
-        if key.startswith('seat_'):
-            try:
-                return {
-                    'item': int(parts[1]),
-                    'variation': int(parts[2]) if len(parts) > 2 else None,
-                    'count': 1,
-                    'seat': value,
-                    'price': price,
-                    'voucher': voucher,
-                    'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
-                    'subevent': subevent
-                }
-            except ValueError:
-                raise CartError(_('Please enter numbers only.'))
+def _item_from_post_value(request, key, value, voucher=None, voucher_ignore_if_redeemed=False):
+    if value.strip() == '' or '_' not in key:
+        return
 
+    subevent = None
+    if key.startswith('subevent_'):
         try:
-            amount = int(value)
+            parts = key.split('_', 2)
+            subevent = int(parts[1])
+            key = parts[2]
+        except ValueError:
+            pass
+    elif 'subevent' in request.POST:
+        try:
+            subevent = int(request.POST.get('subevent'))
         except ValueError:
-            raise CartError(_('Please enter numbers only.'))
-        if amount < 0:
-            raise CartError(_('Please enter positive numbers only.'))
-        elif amount == 0:
-            return
-
-        if key.startswith('item_'):
-            try:
-                return {
-                    'item': int(parts[1]),
-                    'variation': None,
-                    'count': amount,
-                    'price': price,
-                    'voucher': voucher,
-                    'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
-                    'subevent': subevent
-                }
-            except ValueError:
-                raise CartError(_('Please enter numbers only.'))
-        elif key.startswith('variation_'):
-            try:
-                return {
-                    'item': int(parts[1]),
-                    'variation': int(parts[2]),
-                    'count': amount,
-                    'price': price,
-                    'voucher': voucher,
-                    'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
-                    'subevent': subevent
-                }
-            except ValueError:
-                raise CartError(_('Please enter numbers only.'))
-
-    def _items_from_post_data(self):
-        """
-        Parses the POST data and returns a list of dictionaries
-        """
-
-        # Compatibility patch that makes the frontend code a lot easier
-        req_items = list(self.request.POST.lists())
-        if '_voucher_item' in self.request.POST and '_voucher_code' in self.request.POST:
-            req_items.append((
-                '%s' % self.request.POST['_voucher_item'], ('1',)
-            ))
             pass
 
-        items = []
-        if 'raw' in self.request.POST:
-            items += json.loads(self.request.POST.get("raw"))
-        for key, values in req_items:
-            for value in values:
-                try:
-                    item = self._item_from_post_value(key, value, self.request.POST.get('_voucher_code'),
-                                                      voucher_ignore_if_redeemed=self.request.POST.get('_voucher_ignore_if_redeemed') == 'on')
-                except CartError as e:
-                    messages.error(self.request, str(e))
-                    return
-                if item:
-                    items.append(item)
+    if not key.startswith('item_') and not key.startswith('variation_') and not key.startswith('seat_'):
+        return
 
-        if len(items) == 0:
-            messages.warning(self.request, _('You did not select any products.'))
-            return []
-        return items
+    parts = key.split("_")
+    price = request.POST.get('price_' + "_".join(parts[1:]), "")
+
+    if key.startswith('seat_'):
+        try:
+            return {
+                'item': int(parts[1]),
+                'variation': int(parts[2]) if len(parts) > 2 else None,
+                'count': 1,
+                'seat': value,
+                'price': price,
+                'voucher': voucher,
+                'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
+                'subevent': subevent
+            }
+        except ValueError:
+            raise CartError(_('Please enter numbers only.'))
+
+    try:
+        amount = int(value)
+    except ValueError:
+        raise CartError(_('Please enter numbers only.'))
+    if amount < 0:
+        raise CartError(_('Please enter positive numbers only.'))
+    elif amount == 0:
+        return
+
+    if key.startswith('item_'):
+        try:
+            return {
+                'item': int(parts[1]),
+                'variation': None,
+                'count': amount,
+                'price': price,
+                'voucher': voucher,
+                'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
+                'subevent': subevent
+            }
+        except ValueError:
+            raise CartError(_('Please enter numbers only.'))
+    elif key.startswith('variation_'):
+        try:
+            return {
+                'item': int(parts[1]),
+                'variation': int(parts[2]),
+                'count': amount,
+                'price': price,
+                'voucher': voucher,
+                'voucher_ignore_if_redeemed': voucher_ignore_if_redeemed,
+                'subevent': subevent
+            }
+        except ValueError:
+            raise CartError(_('Please enter numbers only.'))
+
+def _items_from_post_data(request):
+    """
+    Parses the POST data and returns a list of dictionaries
+    """
+
+    # Compatibility patch that makes the frontend code a lot easier
+    req_items = list(request.POST.lists())
+    if '_voucher_item' in request.POST and '_voucher_code' in request.POST:
+        req_items.append((
+            '%s' % request.POST['_voucher_item'], ('1',)
+        ))
+        pass
+
+    items = []
+    if 'raw' in request.POST:
+        items += json.loads(request.POST.get("raw"))
+    for key, values in req_items:
+        for value in values:
+            try:
+                item = _item_from_post_value(request, key, value, request.POST.get('_voucher_code'),
+                                                  voucher_ignore_if_redeemed=request.POST.get('_voucher_ignore_if_redeemed') == 'on')
+            except CartError as e:
+                messages.error(request, str(e))
+                return
+            if item:
+                items.append(item)
+
+    if len(items) == 0:
+        messages.warning(request, _('You did not select any products.'))
+        return []
+    return items
 
 
 @scopes_disabled()
@@ -542,7 +543,7 @@ class CartAdd(EventViewMixin, CartActionMixin, AsyncAction, View):
             cs = cart_session(request)
             widget_data = cs.get('widget_data', {})
 
-        items = self._items_from_post_data()
+        items = _items_from_post_data(self.request)
         if items:
             return self.do(self.request.event.id, items, cart_id, translation.get_language(),
                            self.invoice_address.pk, widget_data, self.request.sales_channel.identifier,

src/pretix/presale/views/event.py

@@ -109,7 +109,8 @@ def item_group_by_category(items):
     )
 
 
-def get_grouped_items(event, *, channel: SalesChannel, subevent=None, voucher=None, require_seat=0, base_qs=None, allow_addons=False,
+def get_grouped_items(event, *, channel: SalesChannel, subevent=None, voucher=None, require_seat=0, base_qs=None,
+                      allow_addons=False, allow_cross_sell=False,
                       quota_cache=None, filter_items=None, filter_categories=None, memberships=None,
                       ignore_hide_sold_out_for_item_ids=None):
     base_qs_set = base_qs is not None
@@ -191,7 +192,9 @@ def get_grouped_items(event, *, channel: SalesChannel, subevent=None, voucher=No
         )
     )
 
-    items = base_qs.using(settings.DATABASE_REPLICA).filter_available(channel=channel.identifier, voucher=voucher, allow_addons=allow_addons).select_related(
+    items = base_qs.using(settings.DATABASE_REPLICA).filter_available(
+        channel=channel.identifier, voucher=voucher, allow_addons=allow_addons, allow_cross_sell=allow_cross_sell
+    ).select_related(
         'category', 'tax_rule',  # for re-grouping
         'hidden_if_available',
     ).prefetch_related(