[GitHub] [airflow] dhuang commented on a change in pull request #6793: [AIRFLOW-1076] Add get method for template variable accessor

[GitBox <gi...@apache.org>]

dhuang commented on a change in pull request #6793: [AIRFLOW-1076] Add get method for template variable accessor
URL: https://github.com/apache/airflow/pull/6793#discussion_r357294186
 
 

 ##########
 File path: airflow/models/taskinstance.py
 ##########
 @@ -1178,34 +1178,60 @@ def get_template_context(self, session=None) -> Dict[str, Any]:
 
         class VariableAccessor:
             """
-            Wrapper around Variable. This way you can get variables in templates by using
-            {var.value.your_variable_name}.
+            Wrapper around Variable. This way you can get variables in
+            templates by using {{ var.value.variable_name }} or
+            {{ var.value.get('variable_name', 'fallback') }}.
             """
             def __init__(self):
                 self.var = None
 
-            def __getattr__(self, item):
+            def __getattr__(
+                self,
+                item: str,
+                default_var: Any = Variable._Variable__NO_DEFAULT_SENTINEL,
+            ):
                 self.var = Variable.get(item)
                 return self.var
 
             def __repr__(self):
                 return str(self.var)
 
+            @staticmethod
+            def get(
+                item: str,
+                default_var: Any = Variable._Variable__NO_DEFAULT_SENTINEL,
+            ):
+                self.var = Variable.get(item, default_var=default_var)
+                return self.var
+
         class VariableJsonAccessor:
             """
-            Wrapper around deserialized Variables. This way you can get variables
-            in templates by using {var.json.your_variable_name}.
+            Wrapper around Variable. This way you can get variables in
+            templates by using {{ var.json.variable_name }} or
+            {{ var.json.get('variable_name', {'fall': 'back'}) }}.
             """
             def __init__(self):
                 self.var = None
 
-            def __getattr__(self, item):
-                self.var = Variable.get(item, deserialize_json=True)
+            def __getattr__(
+                self,
+                item: str,
+                default_var: Any = Variable._Variable__NO_DEFAULT_SENTINEL,
 
 Review comment:
   yep had thought I was actually using `_getattr_` when I was doing `self.var` in `get()`, removed.

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