Check if Html element already exists? Or Check if Div has Children?

[newman_jumbalaya]

Is there a way to check if an html element with a given ID exists in Dash?

Or, is there a way to check if a Div with a given ID has Children?

I want to use a chart’s selectedData as an input, but only if that chart exists (i.e. has been created by other callbacks)

[chriddyp]

@newman_jumbalaya

only if that chart exists (i.e. has been created by other callbacks)

you might try out pattern matching callbacks - this pattern is well suited for callbacks that respond to with zero or more elements