handle data without due date

app.py

@@ -27,7 +27,7 @@ class PrintRequest(BaseModel):
     # grocy payload:
     grocycode: str = Field(..., description="Raw GrocyCode")
     product: str = Field(..., description="Product name")
-    due_date: str = Field(None, description="Due date from stock entry")
+    due_date: Optional[str] = Field(None, description="Due date from stock entry")
 
     class Config:
         # ignore any other fields Grocy might send
@@ -35,7 +35,9 @@ class PrintRequest(BaseModel):
 
 
 @lru_cache(maxsize=256)
-def make_code128(grocycode: str, product_name: str, due_date: Optional[str]) -> Image.Image:
+def make_code128(
+    grocycode: str, product_name: str, due_date: Optional[str]
+) -> Image.Image:
     # 1) Instantiate the barcode object (checksum auto-added for Code128)
     code = Code128(grocycode, writer=ImageWriter())
 
@@ -49,7 +51,9 @@ def make_code128(grocycode: str, product_name: str, due_date: Optional[str]) ->
             "text_distance": 5.0,  # gap between bars and text
             # you can also pass 'format': 'PNG' here if needed
         },
-        text=" | ".join([product_name, due_date]),  # explicitly draw your data string under the bars
+        text=(
+            " | ".join([product_name, due_date]) if due_date else product_name
+        ),  # explicitly draw your data string under the bars
     )
 
     # 3) Convert to 1-bit for your Brother QL workflow
@@ -128,7 +132,9 @@ async def print_from_grocy(req: PrintRequest):
     try:
         loop = asyncio.get_running_loop()
         code_img, dm_img = await asyncio.gather(
-            loop.run_in_executor(None, make_code128, req.grocycode, req.product, req.due_date),
+            loop.run_in_executor(
+                None, make_code128, req.grocycode, req.product, req.due_date
+            ),
             loop.run_in_executor(None, make_datamatrix, req.grocycode),
         )
         label_img = compose_label([code_img, dm_img])