Invoice generation: Add way for renderers to signal they are not ready

src/pretix/base/invoicing/pdf.py

@@ -148,6 +148,10 @@ class NumberedCanvas(Canvas):
         self.restoreState()
 
 
+class InvoiceNotReadyException(Exception):
+    pass
+
+
 class BaseInvoiceRenderer:
     """
     This is the base class for all invoice renderers.

src/pretix/base/services/invoices.py

@@ -51,6 +51,7 @@ from django_scopes import scope, scopes_disabled
 from i18nfield.strings import LazyI18nString
 
 from pretix.base.i18n import language
+from pretix.base.invoicing.pdf import InvoiceNotReadyException
 from pretix.base.invoicing.transmission import (
     get_transmission_types, transmission_providers,
 )
@@ -504,7 +505,7 @@ def generate_invoice(order: Order, trigger_pdf=True):
     return invoice
 
 
-@app.task(base=TransactionAwareTask)
+@app.task(base=TransactionAwareTask, throws=(InvoiceNotReadyException,))
 def invoice_pdf_task(invoice: int):
     with scopes_disabled():
         i = Invoice.objects.get(pk=invoice)

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

@@ -1,14 +1,14 @@
 {% extends "pretixpresale/event/base.html" %}
 {% load i18n %}
 {% load bootstrap3 %}
-{% block title %}{% trans "Resend order links" %}{% endblock %}
+{% block title %}{% trans "Resend order link" %}{% endblock %}
 {% block custom_header %}
     {{ block.super }}
     <meta name="robots" content="noindex, nofollow">
 {% endblock %}
 {% block content %}
     <h2>
-        {% trans "Resend order links" %}
+        {% trans "Resend order link" %}
     </h2>
     <p>
         {% blocktrans trimmed %}