The ability to select all potential options in a Shiny input along with a dynamic table

I have the following code below that allows for three different "phases" of selection, each input dependent on the one before. Right now the code exists like this:

  ui <- fluidPage(
  titlePanel("Test Dashboard "),
  sidebarLayout(
    sidebarPanel(
      uiOutput("data1"),   ## uiOutput - gets the UI from the server
      uiOutput("data2"),
      uiOutput("data3")
    ),
    mainPanel()
  ))


server <- function(input, output){
  
  State <- c("NV", "NV","NV", "MD", "MD", "MD", "MD", "NY", "NY", "NY", "OH", "OH", "OH")
  County <- c("CLARK", "WASHOE", "EUREKA", "MONTGOMERY", "HOWARD", "BALTIMORE", "FREDERICK", "BRONX", "QUEENS", "WESTCHESTER", "FRANKLIN", "SUMMIT", "STARK" )
  City <- c("Las Vegas", "Reno", "Eureka", "Rockville", "Columbia", "Baltimore", "Thurmont", "Bronx", "Queens", "Yonkers", "Columbus", "Akron", "Canton")
  Rating<- c(1,2,3,4,5,6,7,8,9,10,11,12,13)
  df <- data.frame(State, County, City, Rating, stringsAsFactors = F)
  
  ## renderUI - renders a UI element on the server
  ## used when the UI element is dynamic/dependant on data
  output$data1 <- renderUI({
    selectInput("data1", "Select State", choices = c(df$State))
  })
  
  ## input dependant on the choices in `data1`
  output$data2 <- renderUI({
    selectInput("data2", "Select County", choices = c(df$County[df$State == input$data1]))
  })
  
  output$data3 <- renderUI({
    selectInput("data3", "select City", choices = c(df$City[df$County == input$data2]))
  })
  
  
}

shinyApp(ui, server)

You will notice the sample data is found in the server side code and binded together to form df.

But what if I didn't want to narrow my choice for each selection? Instead let's say I wanted to follow the following selection path: State = "MD", County = ALL, and City = ALL. While I would have the selection to choose just one or multiple selections, it would also include the selection to choose ALL.

Additionally, I would like to also include a dynamic table that is visible and adjusts itself based on the values selected. So if I were following the same selection path as listed above, it would return all the affiliated results for anything filed under State = "MD".

Whenever I try adding something like

DTOutput('table')

On the UI side and the following on the server side:

output$table <- renderDT(df,
                         options = list(
                           pageLength = 5
                         )
)

It just messes up the whole layout and also doesn't produce the table I need.

Solution

Here is something to try out. You can use updateSelectInput to change your inputs and make them dependent. A separate reactive expression can filter your data based on your inputs. See if this gives you the intended behavior.

library(shiny)
library(DT)

State <- c("NV", "NV","NV", "MD", "MD", "MD", "MD", "NY", "NY", "NY", "OH", "OH", "OH")
County <- c("CLARK", "WASHOE", "EUREKA", "MONTGOMERY", "HOWARD", "BALTIMORE", "FREDERICK", "BRONX", "QUEENS", "WESTCHESTER", "FRANKLIN", "SUMMIT", "STARK" )
City <- c("Las Vegas", "Reno", "Eureka", "Rockville", "Columbia", "Baltimore", "Thurmont", "Bronx", "Queens", "Yonkers", "Columbus", "Akron", "Canton")
Rating<- c(1,2,3,4,5,6,7,8,9,10,11,12,13)
df <- data.frame(State, County, City, Rating, stringsAsFactors = F)

ui <- fluidPage(
  titlePanel("Test Dashboard "),
  sidebarLayout(
    sidebarPanel(
      selectInput("data1", "Select State", choices = c("All", unique(df$State))),
      selectInput("data2", "Select County", choices = NULL),
      selectInput("data3", "select City", choices = NULL)
    ),
    mainPanel(
      DTOutput("table")
    )
  ))

server <- function(input, output, session){
  
  observeEvent(input$data1, {
    if (input$data1 != "All") {
      updateSelectInput(session, "data2", "Select County", choices = c("All", unique(df$County[df$State == input$data1])))
    } else {
      updateSelectInput(session, "data2", "Select County", choices = c("All", unique(df$County)))
    }
  }, priority = 2)
  
  observeEvent(c(input$data1, input$data2), {
    if (input$data2 != "All") {
      updateSelectInput(session, "data3", "Select City", choices = c("All", unique(df$City[df$County == input$data2])))
    } else {
      if (input$data1 != "All") {
        updateSelectInput(session, "data3", "Select City", choices = c("All", unique(df$City[df$State == input$data1])))
      } else {
        updateSelectInput(session, "data3", "Select City", choices = c("All", unique(df$City)))
      }
    }
  }, priority = 1)
  
  filtered_data <- reactive({
    temp_data <- df
    if (input$data1 != "All") {
      temp_data <- temp_data[temp_data$State == input$data1, ]
    }
    if (input$data2 != "All") {
      temp_data <- temp_data[temp_data$County == input$data2, ]
    }
    if (input$data3 != "All") {
      temp_data <- temp_data[temp_data$City == input$data3, ]
    }
    temp_data
  })
  
  output$table <- renderDT(
    filtered_data()
  )
  
}

shinyApp(ui, server)