add creole_client and is_empty in creole_legacy

src/rougail/template/engine/creole_legacy.py

@@ -74,6 +74,27 @@ class IsDefined:
             return varname in self.context
 
 
+class CreoleClient():
+    def get(self, path):
+        path = path.replace('/', '.')
+        if path.startswith('.'):
+            path = path[1:]
+        if '.' not in path:
+            return self.context[path]
+        else:
+            root, path = path.split('.', 1)
+            obj = self.context[root]
+            for var in path.split('.'):
+                obj = getattr(obj, var)
+            return obj
+
+
+def is_empty(data):
+    if str(data) in ['', '""', "''", "[]", "['']", '[""]', "None"]:
+        return True
+    return False
+
+
 class CheetahTemplate(oriCheetahTemplate):
     def __init__(self,
                  filename: str,
@@ -82,7 +103,12 @@ class CheetahTemplate(oriCheetahTemplate):
                  eosfunc: Dict,
                  extra_context: Dict,
                  ):
+        creole_client = CreoleClient()
+        creole_client.context=context
         extra_context['is_defined'] = IsDefined(context)
+        extra_context['creole_client'] = creole_client
+        extra_context['is_empty'] = is_empty
+        extra_context['_creole_filename'] = extra_context['rougail_filename']
         super().__init__(filename, source, context, eosfunc, extra_context)