[bufix] superset views not getting from_dttm-to_dttm in template cont…

…ext (#2978)

superset/connectors/sqla/models.py

@@ -337,13 +337,13 @@ def get_sqla_table(self):
             tbl.schema = self.schema
         return tbl
 
-    def get_from_clause(self):
+    def get_from_clause(self, template_processor=None):
         # Supporting arbitrary SQL statements in place of tables
         if self.sql:
-            tp = self.get_template_processor()
-            from_sql = tp.process_template(self.sql)
+            from_sql = self.sql
+            if template_processor:
+                from_sql = template_processor.process_template(from_sql)
             return TextAsFrom(sa.text(from_sql), []).alias('expr_qry')
-
         return self.get_sqla_table()
 
     def get_sqla_query(  # sqla
@@ -444,7 +444,7 @@ def get_sqla_query(  # sqla
         select_exprs += metrics_exprs
         qry = sa.select(select_exprs)
 
-        tbl = self.get_from_clause()
+        tbl = self.get_from_clause(template_processor)
 
         if not columns:
             qry = qry.group_by(*groupby_exprs)