updatePickerInput default select all choices - r

Question

I know that there is a very similar question on StackExchange (pickerInput default select all choices), however, the solution can not be applied to my problem.
I have a updatePickerInput which is based on two Inputs. on the updatePickerInput I have the selectAll and clearAll buttons from shinyWidgets. I want selectAll to be the default, but since it is dynamically, I dont know how to pass my choices into the selected option.
Here is my relevant ui code:
radioButtons(inputId = 'selected_group', label = 'group', choices = '')
This is my observeEvent code:
observeEvent(c(input$selected_tab,input$selected_group),{
req(input$selected_group)
updatePickerInput(
session,
'selected_subgroup',
choices = df %>%
filter(tab == input$selected_tab) %>%
filter(group == input$selected_group) %>%
select(subgroup) %>%
distinct(subgroup) %>%
arrange(subgroup) %>%
.[[1]]
)
})

Answer 1

To have all options selected dynamically you'll need to pass the same information to updatePickerInput's choices and selected arguments:
library(shiny)
library(datasets)
library(shinyWidgets)
statesDF <- data.frame(region = state.region, name = state.name, area = state.area, stringsAsFactors = FALSE)
ui <- fluidPage(
radioButtons(inputId = 'selected_group', label = 'group', choices = unique(statesDF$region)),
pickerInput(inputId = 'selected_subgroup', label = 'subgroup', choices = NULL, selected = NULL, multiple = TRUE)
)
server <- function(input, output, session) {
filteredChoices <- reactive({
statesDF$name[statesDF$region == input$selected_group]
})
observeEvent(filteredChoices(), {
updatePickerInput(session, inputId = 'selected_subgroup', label = 'subgroup', choices = filteredChoices(), selected = filteredChoices())
})
}
shinyApp(ui = ui, server = server)