streamlit_set_in_bug.py

import streamlit as st

import SessionState


def display_options(session_state):
    """
    Handles loading and editing of DataFrame

            Parameters:
                    session_state (dict): Streamlit SessionState in order to maintain state of dictionary

            Returns:
                    out_value = (str): str
    """
    # load default database
    out_value = 'bananas'

    st.write("#### Choose a value from the list below:")
    session_state.str_list = ['apples', 'oranges', 'grapes']
    # create a container for str selection
    selection_container = st.empty()
    # display database selection
    selected_db = selection_container.radio("", ['Default'] + session_state.str_list)
    # create a message container
    message_placeholder = st.empty()

    # load selected str if not default
    if selected_db != 'Default':
        with st.spinner("Loading..."):
            out_value = selected_db
        message_placeholder.success('Loaded {} successfully'.format(selected_db))

    edit_mode_placeholder = st.empty()
    # edit mode button
    edit_db_mode = edit_mode_placeholder.button('Edit list')
    if edit_db_mode:
        session_state.edit_mode = True

    # enter edit mode
    if session_state.edit_mode:
        message_placeholder.empty()
        edited_selected_str = selection_container.radio("You are editing the list. "
                                                        "Click the exit button twice to exit. "
                                                        "Ignore any \"Bad Message Format\" warnings that may pop up. ",
                                                        session_state.str_list)

        # create a container for edit mode controls
        edit_mode_controls = edit_mode_placeholder.beta_container()
        edit_col1, edit_col2 = edit_mode_controls.beta_columns(2)

        # exit edit mode controls
        exit_edit_mode = edit_col2.button('Exit edit mode')
        if exit_edit_mode:
            session_state.edit_mode = False
        # open delete confirmation dialog
        delete_init = edit_col1.button('Delete selection')
        if delete_init:
            session_state.delete_init = True

        # if begin delete, confirm before deleting
        if session_state.delete_init:
            # clear the container before doing stuff
            edit_mode_placeholder.empty()
            # create a new container in the previous one's place
            delete_mode_controls = edit_mode_placeholder.beta_container()
            # create confirmations
            delete_mode_controls.warning('Are you sure you want to delete the selected database?')
            col1, col2 = delete_mode_controls.beta_columns(2)

            delete_reject = col2.button('No, go back')
            if delete_reject:
                session_state.delete_init = False

            # if confirm delete, then delete str
            delete_confirm = col1.button('Yes, delete it')
            if delete_confirm:
                edited_list = session_state.str_list
                edited_list.remove(edited_selected_str)
                session_state.str_list = edited_list

                # clear the container before doing stuff
                edit_mode_placeholder.empty()
                # create a new container for delete controls
                delete_container = edit_mode_placeholder.beta_container()
                delete_container.success("Delete successful")
                # show go back button with unique key
                exit_edit_mode = delete_container.button('Go back', key='after-delete')
                if exit_edit_mode:
                    session_state.delete_init = False
                    session_state.edit_mode = False

    return out_value


def main():
    st.title('Hello World')
    session_state = SessionState.get(str_list=None, edit_mode=False, delete_init=False)
    with st.sidebar.beta_expander('Options'):
        display_options(session_state)


if __name__ == '__main__':
    main()