move date string to just before prompt() and template it is used in- looks like passing str into RunnablePassthrough() is erroneous

chain.py

@@ -163,7 +163,6 @@ class ChainBuilder:
         # RAG Chain
         chain = (
             {
-                "date_str": datetime.datetime.now().strftime("%B %d, %Y"), # date to be passed to system prompt for context of when knowledge base was last updated
                 "question": itemgetter("messages") | RunnableLambda(self.extract_user_query_string), # set 'question' to the result of: grabbing the ["messages"] component of the dict we 'invoke()' or 'stream()', then passing to extract_user_query_string()
                 "chat_history": itemgetter("messages") | RunnableLambda(self.extract_chat_history),
                 "formatted_chat_history": itemgetter("messages")
@@ -182,6 +181,7 @@ class ChainBuilder:
                 | RunnableLambda(self.format_context), 
                 "formatted_chat_history": itemgetter("formatted_chat_history"),
                 "question": itemgetter("question"),
+                "date_str": datetime.datetime.now().strftime("%B %d, %Y"), # date to be passed to system prompt for context of when knowledge base was last updated
             }
             | self.get_prompt() # 'context', 'formatted_chat_history', and 'question' passed to prompt
             | self.get_model() # prompt passed to model