.

longs/forms.py

@@ -118,6 +118,29 @@ class LongSeriesForm(ModelForm):
             widget=FilteredSelectMultiple(verbose_name="Long", is_stacked=False),
         )
 
+    def save(self, commit=True):
+        # Get the unsaved Pizza instance
+        instance = ModelForm.save(self, False)
+
+        # Prepare a 'save_m2m' method for the form,
+        old_save_m2m = self.save_m2m
+
+        def save_m2m():
+            old_save_m2m()
+            # This is where we actually link the pizza with toppings
+            instance.long.clear()
+            for long in self.cleaned_data["long"]:
+                instance.long.add(long)
+
+        self.save_m2m = save_m2m
+
+        # Do we need to save all changes now?
+        # if commit:
+        instance.save()
+        self.save_m2m()
+
+        return instance
+
     class Meta:
         model = LongSeries
         exclude = ["author"]