Plotly grouped bar chart - start with one selected trace

Question

I want to show only one trace at the beginning of a grouped bar chart in Plotly for R and then progressively reveal more traces when clicking on the legend.

Here is an example:

df <- data.frame(
  Category = c("A", "B", "C", "D"),
  group1= c(10, 20, 15, 30),
  group2= c(15, 25, 20, 35)
)


bar_plot <- plot_ly(df, x = ~Category) %>%
  add_trace(y = ~group1, name = "Group 1", type = 'bar') %>%
  add_trace(y = ~group2, name = "Group 2", type = 'bar') %>%
  layout(barmode = 'group')

bar_plot

Now, it would be great to only have group1 shown at the beginning as default.

Is that possible?

Thanks a lot!

Got trough all possible specifications, was not able to figure it out.

Answer 1

change the second trace to

add_trace(y = ~group2, name = "Group 2", type = 'bar',
            visible="legendonly")