Implement storing asset restriction callbacks

core/models.py

@@ -369,6 +369,10 @@ class Strategy(models.Model):
     trade_size_percent = models.FloatField(default=0.5)
     trends = models.JSONField(null=True, blank=True)
 
+    asset_group = models.ForeignKey(
+        "core.AssetGroup", on_delete=models.PROTECT, null=True, blank=True
+    )
+
     class Meta:
         verbose_name_plural = "strategies"
 
@@ -414,7 +418,7 @@ class AssetGroup(models.Model):
     allowed = models.JSONField(null=True, blank=True, default=dict)
 
     def __str__(self):
-        return self.name
+        return f"{self.name} ({self.restrictions})"
 
     @property
     def matches(self):
@@ -438,7 +442,7 @@ class AssetRestriction(models.Model):
     name = models.CharField(max_length=255)
     description = models.TextField(null=True, blank=True)
     pairs = models.CharField(max_length=4096, null=True, blank=True)
-    pairs_parsed = models.JSONField(null=True, blank=True)
+    pairs_parsed = models.JSONField(null=True, blank=True, default=dict)
 
     webhook_id = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)