app.py

import gradio as gr

def respond(newVal, previous_val):
    if previous_val is None:
        previous_val = newVal
    return previous_val

with gr.Blocks() as demo:
    val = gr.State(None)
    input_text = gr.Textbox(label="Input")
    output_text = gr.Textbox(label="Output")
    submit_button = gr.Button("Submit")

    def on_submit(newVal, previous_val):
        updated_val = respond(newVal, previous_val)
        return updated_val, updated_val

    submit_button.click(on_submit, [input_text, val], [val, output_text])

demo.launch()