Creating a Persistent Text Area?

Using Streamlit
,
3

Thank you for replying. I have tried a wide variety of methods, but none of them have worked.

I first set:

if "code_input" not in st.session_state:
    st.session_state.code_input = ""


# Gets session_state[key] if it exists, or default if it does not
def st_session_state_get_or_default(session_state, key, default = ""):
    if key in session_state:
        return session_state[key]
    else:
        return default

# Define a callback function
# From Streamlit docs assistant
def on_change_text():
    # The value is automatically updated in session state via the key
    pass

and then tried each of the following (among other things that I tried and lost the code for):

# Reset when I changed page
code_input = st.text_area(
    label = "label placeholder", 
    height = 300,
    label_visibility = "hidden"
)

st.session_state.code_input = code_input

# StreamlitAPIException: st.session_state.code_input cannot be modified after the widget with key code_input is instantiated.
st.session_state.code_input = st.text_area(
    label = "Label Placeholder",
    value = st.session_state.code_input,
    height = 300,
    key = "code_input",
    on_change = on_change_text,
    label_visibility = "hidden"
)

# Including this did not seem to help
st.session_state.update(st.session_state)

# Resets after you change the page
st.text_area(
    label = "Label Placeholder",
    value = st.session_state.code_input,
    height = 300,
    key = "code_input",
    label_visibility = "hidden"
)

# Calling the do-nothing function did not fix the issue where the value is lost after you change the page
st.text_area(
    label = "Label Placeholder",
    value = st.session_state.code_input,
    height = 300,
    key = "code_input",
    on_change = on_change_text,
    label_visibility = "hidden"
)

# Resets after you change the page
st.text_area(
    label = "Label Placeholder",
    height = 300,
    key = "code_input", 
    label_visibility = "hidden"
)

# Retains value when switching between pages, but still sometimes resets the text area when clicking outside it
st.session_state.code_input = st.text_area(
    label = "label placeholder", 
    value = st_session_state_get_or_default(st.session_state, "code_input", ""),
    height = 300,
    label_visibility = "hidden"
)

I tried many combinations of setting it to “code_input” and then setting that to “st.session_state.code_input”, storing it directly to “st.session_state.code_input”, and not storing it directly, inputting the existing session state value as the “value” parameter, setting and not setting the key, using a do-nothing function, and calling “st.session_state.update()”. I tried reading up online resources (I found Texts Disappering when users click outside the 'text_area' or switching page, but I don’t think that putting the text area in a form is a good solution for me, as in that case, whatever is typed in will not be saved unless you submit) and asking various chatbots (GPT-4o, Bing Chat, Google Chat, Claude 3.5 Haiku, and a chatbot available on the streamlit documentation), but I could not find any solutions.

This issue may be a bit too niche for these LLMs to know about, so I was hoping that people on this forum would have an idea of how you can create a text area whose contents are not lost when switching pages and which does not randomly lose your changes to it when you click outside it.