Dash button triggering without it being clicked

Dash Python
2

Hi @hrose33 I usually do this:

import dash
from dash import html, Input, Output, ctx, ALL
from dash.exceptions import PreventUpdate

app = dash.Dash(__name__)
app.layout = html.Div([
    html.Button('click', id='btn_0'),
    html.Button('click', id='btn_1'),
    html.Button('click', id={'type': 'btn', 'index': 0}),
    html.Button('click', id={'type': 'btn', 'index': 1}),
    html.Div(id='out')
])


@app.callback(
    Output('out', 'children'),
    Input({'type': 'btn', 'index': ALL}, 'n_clicks'),
    prevent_initial_call=True
)
def do_pattern_matching(_):
    if ctx.triggered_id.index == 0:
        raise PreventUpdate
    return ctx.triggered_id.index


@app.callback(
    Output('out', 'children', allow_duplicate=True),
    Input('btn_0', 'n_clicks'),
    Input('btn_1', 'n_clicks'),
    prevent_initial_call=True
)
def do(*_):
    if ctx.triggered_id == 'btn_0':
        raise PreventUpdate
    return ctx.triggered_id


if __name__ == '__main__':
    app.run(debug=True)

If creating content dynamically I usually do something like this:

import dash
from dash import html, Input, Output, ctx, ALL
from dash.exceptions import PreventUpdate

app = dash.Dash(__name__)
app.layout = html.Div([
    html.Button('create buttons', id='btn_0'),
    html.Div(id='button_container'),
    html.Div(id='out')
])


@app.callback(
    Output('out', 'children'),
    Input({'type': 'btn', 'index': ALL}, 'n_clicks'),
    prevent_initial_call=True
)
def do_pattern_matching(clicks):
    if not any(clicks):
        raise PreventUpdate

    if ctx.triggered_id.index == 0:
        return 'HELLO!'
    return 'HOLA!'


@app.callback(
    Output('button_container', 'children'),
    Input('btn_0', 'n_clicks'),
    prevent_initial_call=True
)
def do(_):
    return html.Div([
        html.Button('click', id={'type': 'btn', 'index': 0}),
        html.Button('click', id={'type': 'btn', 'index': 1}),
    ])


if __name__ == '__main__':
    app.run(debug=True)

mred pmcb