Shiny R: Reset other input values when selectInput value changes

Question

I have a simple app where a user selects a player's name from a selectInput (player_name) dropdown, and then you can choose other filters from selectInputs (season) and radioButtons (contested) which displays a table. Without using a submit or action button, is there anyway to observe that the player_name value has changed, which would then reset the season and contested inputs to their default values? Normally, I'd use a conditionalPanel for input changes, but in this situation, player_name has thousands of players.

Geovany Geovany · Accepted Answer · 2016-08-11T03:30:13

The basic solution for this is to use an extra uiOutput "filters_UI" to put the second selectInput and radioButtons and also add input$player_name to it, so any time that the player name changes, the complete uiOutput will be created again with the initial values. See the example below.

library(shiny)

ui <- fluidPage(
  fluidRow(
    column(6, uiOutput('controls_UI')),
    column(6, DT::dataTableOutput("table_DT"))
  )
)

server <- shinyServer(function(input, output, session) {
  # to simulate players
  dat <- USJudgeRatings
  players <- row.names(dat)
  seasons <-  names(dat)

  output$controls_UI <- renderUI({
    fluidRow(
      column(6, 
        selectInput("player_name", "Players", players, selected = players[1])
      ),
      column(6, 
        uiOutput("filters_UI"))
    )
  })

  # render again if input$player_name changes
  output$filters_UI <- renderUI({
    input$player_name
    fluidRow(
      column(6, 
        selectInput("season", "Season", seasons, selected = seasons[1])
      ),
      column(6, 
        radioButtons("contested", label = "Contested",
          choices = list("Choice 1" = 1, "Choice 2" = 2, "Choice 3" = 3), 
          selected = 1)
      )
    )
  })

  output$table_DT <- DT::renderDataTable(
    datR(),
    options = list(
      scrollX = TRUE, 
      paging = TRUE,
      lengthMenu = c(10, 20, 50)
    ),
    selection = "single",
    rownames = TRUE
  )

  # creates a table based on the sliders and radio buttons
  datR <- reactive({
    input$player_name
    varName <- input$season
    contested <- ifelse(is.null(input$contested),1,as.integer(input$contested))
    dat0 <- data.frame( dat[sample(2:length(players),contested*3), varName] )   
    names(dat0) <- varName
    dat0
  })

})

shinyApp(ui, server)

I hope it could help you.

Shiny R: Reset other input values when selectInput value changes

1 Answers