Allow admins to inspect invoices (#5641)

This is helpful to debug invoice renderers or non-PDF invoices like
Peppol or other XML formats

src/pretix/control/templates/pretixcontrol/order/index.html

@@ -362,6 +362,11 @@
                                             </form>
                                         {% endif %}
                                     {% endif %}
+                                    {% if staff_session %}
+                                        <a class="btn btn-default btn-xs admin-only" href="{% url "control:event.order.inspect" event=request.event.slug organizer=request.event.organizer.slug code=order.code id=i.pk %}">
+                                            {% trans "Inspect" %}
+                                        </a>
+                                    {% endif %}
                                     {% if forloop.revcounter0 > 0 %}
                                         <br/>
                                     {% endif %}

src/pretix/control/urls.py

@@ -391,6 +391,8 @@ urlpatterns = [
                 name='event.order.retransmitinvoice'),
         re_path(r'^orders/(?P<code>[0-9A-Z]+)/invoices/(?P<id>\d+)/reissue$', orders.OrderInvoiceReissue.as_view(),
                 name='event.order.reissueinvoice'),
+        re_path(r'^orders/(?P<code>[0-9A-Z]+)/invoices/(?P<id>\d+)/inspect$', orders.OrderInvoiceInspect.as_view(),
+                name='event.order.inspect'),
         re_path(r'^orders/(?P<code>[0-9A-Z]+)/download/(?P<position>\d+)/(?P<output>[^/]+)/$',
                 orders.OrderDownload.as_view(),
                 name='event.order.download.ticket'),

src/pretix/control/views/orders.py

@@ -131,13 +131,16 @@ from pretix.control.forms.orders import (
     ReactivateOrderForm,
 )
 from pretix.control.forms.rrule import RRuleForm
-from pretix.control.permissions import EventPermissionRequiredMixin
+from pretix.control.permissions import (
+    AdministratorPermissionRequiredMixin, EventPermissionRequiredMixin,
+)
 from pretix.control.signals import order_search_forms
 from pretix.control.views import PaginationMixin
 from pretix.helpers import OF_SELF
 from pretix.helpers.compat import CompatDeleteView
 from pretix.helpers.format import SafeFormatter, format_map
 from pretix.helpers.hierarkey import clean_filename
+from pretix.helpers.json import CustomJSONEncoder
 from pretix.helpers.safedownload import check_token
 from pretix.presale.signals import question_form_fields
 
@@ -1752,6 +1755,25 @@ class OrderInvoiceReissue(OrderView):
         return HttpResponseNotAllowed(['POST'])
 
 
+class OrderInvoiceInspect(AdministratorPermissionRequiredMixin, OrderView):
+
+    def get(self, *args, **kwargs):  # NOQA
+        inv = get_object_or_404(self.order.invoices, pk=kwargs.get('id'))
+        d = {"lines": []}
+        for f in inv._meta.fields:
+            v = getattr(inv, f.name)
+            d[f.name] = v
+
+        for il in inv.lines.all():
+            line = {}
+            for f in il._meta.fields:
+                v = getattr(il, f.name)
+                line[f.name] = v
+            d["lines"].append(line)
+
+        return JsonResponse(d, encoder=CustomJSONEncoder)
+
+
 class OrderResendLink(OrderView):
     permission = 'can_change_orders'