Minimal nested select input with {shinyTree}

shinyTree_nested_select.R

library(shiny)
library(shinyTree)
library(highcharter)
library(dplyr)

pokemon_df <- highcharter::pokemon |> 
  select(primary = type_1, secondary = type_2, pokemon) |> 
  mutate(secondary = coalesce(secondary, primary))
  
pokemon_list <- shinyTree::dfToTree(pokemon_df)

ui <- fluidPage(
  titlePanel("Minimal nested select input with {shinyTree}"),
  sidebarLayout(
    sidebarPanel(
      actionButton("plot_button", "Plot:"),
      shinyTree("pokemon_tree", checkbox = TRUE, themeIcons = FALSE)
    ),
    mainPanel(
      highchartOutput("pokemon_treemap")
    )
  )
)

server <- function(input, output, session) {
  
  # Shiny Tree variable selection logic
  output$pokemon_tree <- renderTree({ list(All = structure(pokemon_list, stselected = TRUE, stopened = TRUE)) })

  # Reactive on tree state (incl. opened and closed subtrees) and terminal node selections
  pokemon_tree_selected <- reactive({
    unlist(get_selected(input$pokemon_tree), use.names = FALSE)
  })
  pokemon_selected <- reactive({
    intersect(pokemon_df$pokemon, pokemon_tree_selected())
  })
  
  # Highchart treemap render logic
  output$pokemon_treemap <- renderHighchart({
    
    input$plot_button
    
    pokemon_df |> 
      filter(pokemon %in% isolate(pokemon_selected())) |> 
      count(primary, secondary) |> 
      data_to_hierarchical(
        group_vars = c("primary", "secondary"), size_var = "n"
      ) |>
      hchart(type = "treemap")
  })
  
}

shinyApp(ui, server)