Change Plot Output Based on checkboxInput Selection Shiny

Question

Overview
Hello, I am trying to work with displaying different plots using checkboxes within tabsetPanels. I am working with a dynamic amount number of panels, so that is the reason for creating the UI contents within the server portion.

Ideal Output
For each tabPanel:
iris plot outputs if no checkboxes are selected
mtcars plot outputs if Box One is selected
islands plot outputs if Box Two is selected
sleep plot outputs if both Box One and Box Two are selected

What I have tried
-I have tried to use condtionalPanels to try to & capture the cases. I was under the impression that the value returns 'TRUE' if checked & 'FALSE' if unchecked, however I receive NULL for each of the boxed values, even if I set the default value to be checked.
-I believe my underlying issue is my lack of ability to trigger the dynamic checkboxes for each tabPanel

Disclaimer
This is a reproducible example, the default values of originally created tabPanels is set to 5. I did not accommodate proper code if the value were to change for the sake of simplicity.

Sample Code:

ui <- navbarPage(title="Dynamic tabsetPanels",id="navbar",
                 tabPanel("Home",
                          textInput(inputId = "numPanels",
                                    label = "Enter # of Panels to produce",
                                    value = 5)
                 ),tabPanel("Analysis",
                            tabsetPanel(id = "tabs"))
) 
  server <- function(input, output) {
    plotOne = renderPlot({plot(iris)})
    plotTwo = renderPlot({plot(mtcars)})
    plotThree = renderPlot({plot(islands)})
    plotFour = renderPlot({plot(sleep)})
    observe({
      req(input$numPanels)
      lapply(1:input$numPanels,function(i){
        tabName = paste("Tab",i,sep=" ")
        first = paste0("first",i)
        second = paste0("second",i)
        appendTab(inputId = "tabs",
                  tab = tabPanel(
                    tabName,
                    fluidPage(
                      sidebarLayout(
                        sidebarPanel(
                          #side-panel code
                          h2("Features"),
                          checkboxInput(inputId=first,label="Box One"),
                          checkboxInput(inputId=second,label="Box Two")
                        ),mainPanel(
                          #output when nothing clicked
                          conditionalPanel(
                            condition = "!glue(input.{first} && !glue(input.{second})",
                            plotOutput(iris)
                          ),
                          #output when box one is clicked
                          conditionalPanel(
                            condition = "glue(input.{first})",
                            plotOutput(mtcars)
                          ),
                          #output when box two is clicked
                          conditionalPanel(
                            condition = "glue(input.{second})",
                            plotOutput(islands)
                          ),
                          #output when box one and two are clicked
                          conditionalPanel(
                            condition = "glue(input.{first}) && glue(input.{second})",
                            plotOutput(sleep)
                          )
                        )
                      )
                    )
                  )
                  )
      })
    })
  }
  shinyApp(ui=ui, server=server)

Any suggestions would be greatly appreciated!

Answer 1

First issue with your code is the use of glue to create your conditions, i.e. you have to do e.g. condition = glue("input.{first}") instead of condition = "glue(input.{first})" to evaluate the glue string. Second issue is that in the plotOutputs you have to use the names of the outputs, e.g. plotOutput("plotOne") instead of plotOutput(iris). Finally, even after fixing these issues your app will not work as desired as you can't use outputs with the same id in several places or tabs, i.e. you get a duplicated id error. To fix that you also have to create a dynamic list of outputs so that the ids are unique.

library(shiny)
library(glue)

ui <- navbarPage(
  title = "Dynamic tabsetPanels", id = "navbar",
  tabPanel(
    "Home",
    textInput(
      inputId = "numPanels",
      label = "Enter # of Panels to produce",
      value = 5
    )
  ), tabPanel(
    "Analysis",
    tabsetPanel(id = "tabs")
  )
)
server <- function(input, output) {
  observe({
    req(input$numPanels)
    lapply(1:input$numPanels, function(i) {
      output[[paste0("plotOne", i)]] <- renderPlot(plot(iris))
      output[[paste0("plotTwo", i)]] <- renderPlot(plot(mtcars))
      output[[paste0("plotThree", i)]] <- renderPlot(plot(islands))
      output[[paste0("plotFour", i)]] <- renderPlot(plot(sleep))
    })
  })
  
  observe({
    req(input$numPanels)
    lapply(1:input$numPanels, function(i) {
      tabName <- paste("Tab", i, sep = " ")
      first <- paste0("first", i)
      second <- paste0("second", i)
      appendTab(
        inputId = "tabs",
        tab = tabPanel(
          tabName,
          fluidPage(
            sidebarLayout(
              sidebarPanel(
                # side-panel code
                h2("Features"),
                checkboxInput(inputId = first, label = "Box One"),
                checkboxInput(inputId = second, label = "Box Two")
              ), mainPanel(
                # output when nothing clicked
                conditionalPanel(
                  condition = glue("!input.{first} && !input.{second}"),
                  plotOutput(paste0("plotOne", i))
                ),
                # output when box one is clicked
                conditionalPanel(
                  condition = glue("input.{first}"),
                  plotOutput(paste0("plotTwo", i))
                ),
                # output when box two is clicked
                conditionalPanel(
                  condition = glue("input.{second}"),
                  plotOutput(paste0("plotThree", i))
                ),
                # output when box one and two are clicked
                conditionalPanel(
                  condition = glue("input.{first} && input.{second}"),
                  plotOutput(paste0("plotFour", i))
                )
              )
            )
          )
        )
      )
    })
  })
}
shinyApp(ui = ui, server = server)