Cleanup get_required_parts function

InvenTree/part/models.py

@@ -931,13 +931,26 @@ class Part(MPTTModel):
 
         self.bom_items.all().delete()
 
-    def required_parts(self):
-        """ Return a list of parts required to make this part (list of BOM items) """
-        parts = []
+    def getRequiredParts(self, recursive=False, parts=set()):
+        """
+        Return a list of parts required to make this part (i.e. BOM items).
+
+        Args:
+            recursive: If True iterate down through sub-assemblies
+            parts: Set of parts already found (to prevent recursion issues)
+        """
+
+        for bom_item in self.bom_items.all().select_related('sub_part'):
+
+            sub_part = bom_item.sub_part
+
+            if sub_part not in parts:
+
+                parts.add(sub_part)
+
+                if recursive:
+                    sub_part.getRequiredParts(recursive=True, parts=parts)
 
-        for bom in self.bom_items.all().select_related('sub_part'):
-            parts.append(bom.sub_part)
-        
         return parts
 
     def get_allowed_bom_items(self):

InvenTree/part/views.py

@@ -2127,7 +2127,7 @@ class BomItemCreate(AjaxCreateView):
             query = query.filter(active=True)
             
             # Eliminate any options that are already in the BOM!
-            query = query.exclude(id__in=[item.id for item in part.required_parts()])
+            query = query.exclude(id__in=[item.id for item in part.getRequiredParts()])
             
             form.fields['sub_part'].queryset = query
 
@@ -2195,7 +2195,7 @@ class BomItemEdit(AjaxUpdateView):
             except ValueError:
                 sub_part_id = -1
 
-            existing = [item.pk for item in part.required_parts()]
+            existing = [item.pk for item in part.getRequiredParts()]
 
             if sub_part_id in existing:
                 existing.remove(sub_part_id)