Page refreshes after file upload

[Manu]

Hi all,

I am trying to upload a file. The upload button works fine, able to upload file but after upload the page refreshes and view is same page without login. Could someone please share ideas/approaches for multi page app where logged in is visible only after successful login. (Only Login and Signup are options in sidebar at every page.)

Code:

placeholder = st.empty()

buff, col, buff2 = placeholder.beta_columns([3, 9, 3])

col.write("---------------------------------------------")

uploaded_file = col.file_uploader("Upload the source data file", type=['csv'])

time.sleep(10)

if uploaded_file.data:
    ...
    ... rest of the code for uploaded file's processing

I tested with time.sleep() and the page remains as long as sleep lasts but does not reach the check for uploaded_file is not None

Is this a wrong approach since I want to have uploader within width of col?

[feliperoque]

Hi @Manu.This is a problem which doesn’t have a oficial solution, called SessionState. There are some workarounds the community created, you can check this out here:

Is there any working example for Session State for streamlit version >= 0.63.1

Hello, I have tried every example I can find on the forums for preserving session state and all of them throw errors related to something the session class doesn’t contain. Is there a working example anywhere that will allow me to save session state using any method for streamlit version 0.63.1? Is the solution that this version or streamlit doesnt work yet and I need to use an older version? If so which version will allow me to save session state using any method that works? My use case is t…

Multi-page app with session state

Edit: Streamlit 0.84.0 has officially introduced session state. Go check it out: Session State for Streamlit Hello there For a project I needed to build multi-page app with a settings page. As I’ve seen this topic requesting the feature, I decided to share the solution I came up with. It features a custom version of @thiago’s SessionState. It still relies on hacks, but it should work in most cases. It was tested with Streamlit version 0.61.0 (and now 0.65). Things you must…

While i was develop my streamlit app, i had a similar problem as you, but was with st.number_input. Recently streamlit launch a new feature called st.forms which the aim is prevent the input that are located inside this form do not refresh, you can check following the link below:

https://blog.streamlit.io/introducing-submit-button-and-forms/

Here there is a snippet of my code which include maybe the problem you facing:

p_toleranciamento = st.number_input("Percentage of Tolerance (P or K): ")

        t_tolerancia = st.number_input("Tolerance (T): ")

        n_desvios_padroes = st.number_input("Number of Standard Deviation (w): ")

        #qtd_pontos = st.number_input("Digite a Quantidade de Amostras (n): ")

        # Botão para calcular o índice Cg

        submit_button_1 = st.form_submit_button(label="Submit Values")

        # Calculo do indice de capabilidade Cg:

        if submit_button_1:

            col1, mid, col2 = st.beta_columns([10,5,20])

            with col1:

                df2 = df.rename(columns={'AMOSTRA':'Samples'}, inplace=True)

[Manu]

Hi, thanks for you reply @feliperoque. And surely will check out Submit buttons and Forms and replace in the code.

I am already using SessionState to pass data along to multiple pages… The weird issue here seems to be the break in flow even after I upload file and process it on the same page. I hope this clears the question a bit more. As soon the file is uploaded the page sort of disappears even after having the process logic for it immediately after the file uploader.

Will try submit_form and check once.