Allow to print expiry date of gift card in PDFs (#2560)

src/pretix/base/pdf.py

@@ -49,6 +49,7 @@ from arabic_reshaper import ArabicReshaper
 from bidi.algorithm import get_display
 from django.conf import settings
 from django.contrib.staticfiles import finders
+from django.db.models import Max, Min
 from django.dispatch import receiver
 from django.utils.formats import date_format
 from django.utils.functional import SimpleLazyObject
@@ -418,6 +419,17 @@ DEFAULT_VARIABLES = OrderedDict((
         "editor_sample": _("2017-05-31 19:00"),
         "evaluate": lambda op, order, ev: get_first_scan(op)
     }),
+    ("giftcard_issuance_date", {
+
+        "label": _("Gift card: Issuance date"),
+        "editor_sample": _("2017-05-31"),
+        "evaluate": lambda op, order, ev: get_giftcard_issuance(op, ev)
+    }),
+    ("giftcard_expiry_date", {
+        "label": _("Gift card: Expiration date"),
+        "editor_sample": _("2017-05-31"),
+        "evaluate": lambda op, order, ev: get_giftcard_expiry(op, ev)
+    }),
 ))
 DEFAULT_IMAGES = OrderedDict([])
 
@@ -553,6 +565,24 @@ def get_variables(event):
     return v
 
 
+def get_giftcard_expiry(op: OrderPosition, ev):
+    if not op.item.issue_giftcard:
+        return ""  # performance optimization
+    m = op.issued_gift_cards.aggregate(m=Min('expires'))['m']
+    if not m:
+        return ""
+    return date_format(m.astimezone(ev.timezone), "SHORT_DATE_FORMAT")
+
+
+def get_giftcard_issuance(op: OrderPosition, ev):
+    if not op.item.issue_giftcard:
+        return ""  # performance optimization
+    m = op.issued_gift_cards.aggregate(m=Max('issuance'))['m']
+    if not m:
+        return ""
+    return date_format(m.astimezone(ev.timezone), "SHORT_DATE_FORMAT")
+
+
 def get_first_scan(op: OrderPosition):
     scans = list(op.checkins.all())