multiple filter_select with subsetting choices

[micboat]

Hi

Am not sure how to ensure that muni_filter shows only "A" to "E" as choice to select from after selecting "North" in region_filter. Is that possible with crosstalk. Here is my example in R,

Sample data

df <- data.frame(
region = rep(c("North", "South", "East", "West"), each = 5),
muni = c("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T"),
value = runif(20, 10, 100)
)

Create shared data objects

sd <- SharedData$new(df, key = ~muni, group = "shared_group")

Region filter

region_filter <- filter_select(
id = "region",
label = "Select Region:",
sharedData = sd,
group = ~region,
multiple = FALSE
)

Municipality filter

muni_filter <- filter_select(
id = "muni",
label = "Select Municipality:",
sharedData = sd,
group = ~muni,
multiple = FALSE
)

Arrange the filters in a column layout

filter_panel <- bscols(
widths = c(4, 4),
region_filter,
muni_filter
)