[GitHub] [airflow] yuqian90 commented on issue #12757: Graph View is empty when Operator has multiline string in args (v2.0)

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yuqian90 commented on issue #12757:
URL: https://github.com/apache/airflow/issues/12757#issuecomment-739147569


   Thanks @kaxil  and @ielizarov. This issue can be reproduced with a simpler example like this. I put up a fix in https://github.com/apache/airflow/pull/12829
   
   ```python
   from airflow import DAG
   from airflow.operators.dummy_operator import DummyOperator
   from airflow.utils.dates import days_ago
   
   dag = DAG(dag_id='example_graph_view_issue', start_date=days_ago(2))
   op1 = DummyOperator(task_id='op1', dag=dag)
   op2 = DummyOperator(task_id='op2')
   op1 >> op2
   ```
   
   While this is indeed an inconsistent behaviour and the fix is straightforward, I wonder why we wanted to support ambiguous usage like this. It would be much cleaner for the user to set the dag properly for each task. Or they can also use context manager to create the DAG to avoid this issue. I find the following much cleaner:
   
   ```python
   from airflow import DAG
   from airflow.operators.dummy_operator import DummyOperator
   from airflow.utils.dates import days_ago
   
   with DAG(dag_id='example_graph_view_issue', start_date=days_ago(2)) as dag:
       op1 = DummyOperator(task_id='op1')
       op2 = DummyOperator(task_id='op2')
       op1 >> op2
   ```
   


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