Add badge printing capabilities (#868)

Add badge printing capabilities

src/pretix/plugins/badges/tasks.py

@@ -0,0 +1,24 @@
+import logging
+from typing import List
+
+from django.core.files.base import ContentFile
+
+from pretix.base.models import (
+    CachedFile, Event, OrderPosition, cachedfile_name,
+)
+from pretix.celery_app import app
+
+from .exporters import render_pdf
+
+logger = logging.getLogger(__name__)
+
+
+@app.task()
+def badges_create_pdf(fileid: int, event: int, orders: List[int]) -> int:
+    file = CachedFile.objects.get(id=fileid)
+    event = Event.objects.get(id=event)
+
+    pdfcontent = render_pdf(event, OrderPosition.objects.filter(order_id__in=orders))
+    file.file.save(cachedfile_name(file, file.filename), ContentFile(pdfcontent.read()))
+    file.save()
+    return file.pk