Row Deletion Not Working After Adding a New Entry

I’ve built a streamlit app to display and edit the content of a csv file. I use Aggrid to display the csv as a dataframe, and allow the user to add a line to the dataframe, and delete lines selected with a checkbox. My problem:

  • when the user starts by deleting a line directly, it works
  • when the user first adds a new line and THEN tries to delete a line, it does not work. The app does not recognize that a line (or multiple lines) have been selected with the checkboxes. In order to get this recognized, the user has to select the lines and click “Delete” a second time.

Here is a minimal working example:

import streamlit as st
import pandas as pd
from st_aggrid import AgGrid, GridUpdateMode, DataReturnMode, GridOptionsBuilder

st.set_page_config(layout="wide")

# Initialize DataFrame in session state for demonstration
if 'df' not in st.session_state:
    st.session_state.df = pd.DataFrame({
        'custom_id': [1, 2, 3],
        'question': ['Q1', 'Q2', 'Q3'],
        'response': ['R1', 'R2', 'R3'],
    })

# Display the grid with AgGrid
grid_table = AgGrid(
    st.session_state.df,
    update_mode=GridUpdateMode.MODEL_CHANGED,
    data_return_mode=DataReturnMode.AS_INPUT,
    theme="material",
)

st.session_state.df = grid_table['data']

# Button to delete selected rows
if st.button('Delete'):
    selected = grid_table["selected_rows"]
    if selected:
        selected_custom_ids = [row['custom_id'] for row in selected]
        st.session_state.df = st.session_state.df[~st.session_state.df['custom_id'].isin(selected_custom_ids)]
        st.session_state.entry_deleted = True
        st.rerun()
    else:
        st.warning("Please select rows before deleting.")

# Button to toggle the form display
if st.button("Add an entry"):
    st.session_state.show_form = not st.session_state.show_form

# Form to add a new entry
if st.session_state.show_form:
    with st.form("add_entry_form"):
        question = st.text_area("Question", height=30)
        response = st.text_area("Response", height=100)
        synonyms = st.text_area("Synonyms (optional)", height=100)
        submit_button = st.form_submit_button("Add")
        
        if submit_button:
            if not question or not response:
                st.error("Please fill in all required fields.")
            else:
                next_custom_id = st.session_state.df['custom_id'].astype(int).max() + 1
                new_entry = pd.DataFrame({
                    'custom_id': [next_custom_id],
                    'question': [question],
                    'response': [response],
                    'synonyms': [synonyms]
                })
                st.session_state.df = pd.concat([st.session_state.df, new_entry], ignore_index=True)
                st.session_state.show_form = False
                st.session_state.entry_added = True
                st.rerun()

The problem might be coming from st.rerun(), which I’m using because otherwise the database displayed by AgGrid is not refreshed. But what is going on exactly and how can I fix it?

anyone please? This is the last bug of my app and I need to fix it. :smiley: