streaming_response.py

from langchain.callbacks.base import BaseCallbackHandler


class StreamHandler(BaseCallbackHandler):
    def __init__(self, container, initial_text=""):
        self.container = container
        self.text = initial_text

    def on_llm_new_token(self, token: str, **kwargs) -> None:
        self.text += token
        self.container.markdown(self.text)


# with st.sidebar:
#     openai_api_key = st.text_input("OpenAI API Key", type="password")

# if "messages" not in st.session_state:
#     st.session_state["messages"] = [ChatMessage(role="assistant", content="How can I help you?")]

# for msg in st.session_state.messages:
#     st.chat_message(msg.role).write(msg.content)

# if prompt := st.chat_input():
#     st.session_state.messages.append(ChatMessage(role="user", content=prompt))
#     st.chat_message("user").write(prompt)

#     if not openai_api_key:
#         st.info("Please add your OpenAI API key to continue.")
#         st.stop()

#     with st.chat_message("assistant"):
#         stream_handler = StreamHandler(st.empty())
#         # llm = ChatOpenAI(openai_api_key=openai_api_key, streaming=True, callbacks=[stream_handler])
#         llm = ChatCohere(openai_api_key=openai_api_key, streaming=True, callbacks=[stream_handler])
#         response = llm.invoke(st.session_state.messages)
#         st.session_state.messages.append(ChatMessage(role="assistant", content=response.content))