wallets per person - slow implementation

core/models/survex.py

@@ -203,18 +203,26 @@ class Wallet(models.Model):
 
     # Yes this is horribly, horribly inefficient, esp. for a page that have date, people and cave in it
     def date(self):
+        if not self.get_json():
+            return None
         jsondata = self.get_json()
         return jsondata["date"]
         
     def people(self):
+        if not self.get_json():
+            return None
         jsondata = self.get_json()
         return jsondata["people"]
         
     def cave(self):
+        if not self.get_json():
+            return None
         jsondata = self.get_json()
         return jsondata["cave"]
 
     def name(self):
+        if not self.get_json():
+            return None
         jsondata = self.get_json()
         return jsondata["name"]