Shiny + DT: how to make datatable reactive?

Question

I have an issue while trying to make datatable reactive within a shiny app (from DT package). Here is my reproducible example:

ui.r

dashboardPage(

  dashboardHeader(title = "TEST reactive DT"),

  dashboardSidebar(
    sidebarMenu(
      menuItem("See data", tabName = "db"),
      menuItem("Test", tabName = "test")),
      radioButtons("rb1", label = "Select data", 
                 choices = list("IRIS" = "iris", "CARS" = "cars"),
                 selected = "iris")
    ),

  dashboardBody(
    tabItems(
      tabItem(tabName = "db",
              h4("Show selected dataset"),
              fluidRow(DT::dataTableOutput('tbl')) #THIS DOES NOT WORK (NOT REACTIVE)
              ),
      tabItem(tabName = "test",
              h4("Test tab"),
              fluidRow(column(3, verbatimTextOutput("value"))) #THIS WORKS
              )
      )
    )
)  

server.r

library(shiny)
library(shinydashboard)

server <- function(input, output, session) {

  output$value <- renderPrint({ input$rb1 })

  data <- reactive({
    switch(input$rb1,
           "iris" = iris,
           cars)
  })

  action <- dataTableAjax(session, cars)  # HOW SHOULD I SPECIFY? data() INSTEAD OF cars DOES NOT WORK
  widget <- datatable(cars,  # HOW SHOULD I SPECIFY? data() INSTEAD OF cars DOES NOT WORK
                     class = 'display cell-border compact',
                     filter = 'top',
                     server = TRUE,
                     options = list(ajax = list(url = action))
  )

  output$tbl <- DT::renderDataTable(widget)
}

As you can see in the 'Test tab', radiobutton selection is updated at change. However I can't understand how this should be integrated within the dataTableAjax and dataTable functions, can you explain/ help me solve this issue?

Many thanks in advance for your help!

Best regards

Answer 1

Solution found:

ui.R

## ui.R ##

dashboardPage(

  dashboardHeader(title = "TEST reactive DT"),

  dashboardSidebar(
    sidebarMenu(
      menuItem("See data", tabName = "db")
      ),
      radioButtons("rb1", label = "Select data", 
                 choices = list("IRIS" = "iris", "CARS" = "cars"),
                 selected = "iris")
    ),

  dashboardBody(
    tabItems(
      tabItem(tabName = "db",
              h4("Show selected dataset"),
              fluidRow(DT::dataTableOutput('tbl2'))
              )
      )
    )
)  

server.R

## server.R ##
library(shiny)
library(shinydashboard)

server <- function(input, output, session) {

  output$value <- renderPrint({ input$rb1 })

  data <- reactive({
    switch(input$rb1,
           "iris" = iris,
           cars)
  })

  action <- dataTableAjax(session, cars)
  widget <- datatable(cars, 
                     class = 'display cell-border compact',
                     filter = 'top',
                     server = TRUE,
                     options = list(ajax = list(url = action))
  )

  output$tbl2 <- DT::renderDataTable({
           DT::datatable(data())
  })
}