R Studio: Chained Dorpdown

Plotly R, MATLAB, Julia, Net Plotly R
1

Hi all,

I have a dataframe which contains the columns “country”, “continent” and “value”.

I would like to program two dropdown menues which display the respective graph (column “value”):

  1. dropdown: User can select the continent
    and in the 2. dropdown field are only the countries which have the same continent as selected in the first dropdown menue.

I am using R Studio, Rmarkdown and Plot_ly
Example:

  1. dropdown menue (continent): “Europe” selected
  2. dropdown menue: “Austria” selected
    Result: shows the graph of the “value” column for Austria.

I basically have the two dropdown menues (and the entries) but I can’t connect them with each other.

Can anyone help me?

My code is:

 continents <- c("Africa", "Asia", "Australia", "Europe", "North America", "South America")
 
 p2 <- Data_local_indices_m %>% 
  unnest(.sep = "_") %>%
  mutate(data_date=as.yearmon(data_date)) %>% 
  select(country,data_date,IS_data_turb) %>%
  plot_ly(
    mode = 'lines', 
    x = ~data_date, 
    y = ~IS_data_turb,
    transforms = list(
      list(
        type = 'filter', 
        target = ~country, 
        operation = '==', 
        value = unique(Data_local_indices_m$country)[1]))) %>% 
  layout(
    updatemenus = list(list(
      active = 3,
         y = 0.9,
         buttons = list(

           list(method = "restyle",
                args = list("visible", list(FALSE, TRUE)),
                label = continents[1]),

           list(method = "restyle",
                args = list("visible", list(FALSE, TRUE)),
                label = continents[2]), 
       
           list(method = "restyle",
                args = list("visible", list(FALSE, TRUE)),
                label = continents[3]),
                  
           list(method = "restyle",
                args = list("visible", list(TRUE, FALSE)),
                label = continents[4]),
       
           list(method = "restyle",
                args = list("visible", list(FALSE, TRUE)),
                label = continents[5]),
       
           list(method = "restyle",
                args = list("visible", list(FALSE, TRUE)),
                label = continents[6]))),
       
       list(
         #active = 0,
         y = 0.8,
         x = -0.101,
         buttons = list(
             list(
                method = "restyle",
                args = list("transforms[0].value", unique(Data_local_indices_m$country)[1]),
                label = unique(Data_local_indices_m$country)[1]),

           list(method = "restyle",
                args = list("transforms[0].value", unique(Data_local_indices_m$country)[2]),
                label = unique(Data_local_indices_m$country)[2]),
           
           list(method = "restyle",
                args = list("transforms[0].value", unique(Data_local_indices_m$country)[3]),
                label = unique(Data_local_indices_m$country)[3]),
           
           list(method = "restyle",
                args = list("transforms[0].value", unique(Data_local_indices_m$country)[4]),
                label = unique(Data_local_indices_m$country)[4])
           )
         )
     )
   )

Many thanks for your help!