Cannot read properties of undefined (reading 'setIn')

Using Streamlit
,
#1

Hello,

I’m building a simple application and want to show or hide the contents of a container based on a flag in the session state. The main layout looks like this:

main = st.container()
main.title(title)
body = main.container()
code_container = main.container()
state = main.container()

There is a button which has a method to set the state. When I attempt to operate on that state in code, however, this error is thrown when I click the button.

with code_container:
    if st.session_state.showing_code is True:
        st.write("hi")
    else:
        st.empty()

What am I missing? Thanks for taking the time to consider this - really appreciate it.

This is Streamlit, version 1.10.0

#2

Ah, I figured this out. I was creating content of the container above it later down the line, so the previous container which should have appeared where I wanted to show the code didn’t have any content in it. I fixed it by adding these lines. I did one above the state for good measure, as well, though not strictly necessary in my app right now.

main = st.container()
main.title(title)
body = main.container()
body.empty()  # +++
code_container = main.container()
code_container.empty()  # +++
state = main.container()