Improve navigating trades and positions by cross-linking

core/models.py

@@ -207,6 +207,20 @@ class Trade(models.Model):
         # close the trade
         super().delete(*args, **kwargs)
 
+    @classmethod
+    def get_by_id(cls, trade_id, user):
+        return cls.objects.get(id=trade_id, user=user)
+
+    @classmethod
+    def get_by_id_or_order(cls, trade_id, user):
+        try:
+            return cls.objects.get(id=trade_id, user=user)
+        except cls.DoesNotExist:
+            try:
+                return cls.objects.get(order_id=trade_id, user=user)
+            except cls.DoesNotExist:
+                return None
+
 
 class Callback(models.Model):
     hook = models.ForeignKey(Hook, on_delete=models.CASCADE)