My project would be to create a shiny app that does the following:

1. ask the user how many strings he would like to insert (a number between 1 and 6)
2. based on the number I would like to obtain, with a for or while loop, enter the strings to the user.

The first point I succeeded, the problem lies in the second. I don't understand how to save the value obtained in the first point as a number so that I can use it in a while (or for) loop. I enter my attempt wrong.

library(shiny)

ui <- fluidPage(
        radioButtons(
            "radio", 
            label = HTML(
                '<FONT>Conjoint analysis</FONT>
                <b> How many attributes do you want to insert??</b>'),
            choices = list("1" = 1, "2" = 2, "3"=3, "4"=4, "5"=5, "6"=6),
            inline = T)
      ),

   
server <- function(input, output){
              output$value <- renderPrint({
                  i<-input$radio,
                  while(i>=0){
                      return(textInput(
                          inputId="title",
                          label= "Scrivi:")),
                      i=i-1
                  }
              })
          } 


shinyApp(ui = ui, server = server)

CodePudding user response：

Here is an example that may be helpful. Add generic uiOutput to your ui and then renderUI (as mentioned in comments) that can dynamically create the textInput fields you need. I would use lapply instead of a loop.

In addition, I added renderTable that will display the entered values taken from the inputs for demonstration.

library(shiny)

ui <- fluidPage(
  radioButtons(
    "radio", 
    label = HTML(
      '<FONT>Conjoint analysis</FONT>
       <b>How many attributes do you want to insert?</b>'),
    choices = 1:6,
    inline = T),
  uiOutput("input_ui"),
  tableOutput("table")
)

server <- function(input, output){
  
  output$input_ui <- renderUI({
    lapply(1:input$radio, function(i) {
      textInput(paste0("title_", i), label = paste0("Scrivi:", i))
    })
  })
  
  output$table <- renderTable({
    data.frame(lapply(1:input$radio, function(i) {
      input[[paste0("title_", i)]]
    }))
  })
  
}

shinyApp(ui = ui, server = server)

Edit: Here is an example with side-by-side inputs. Here I used verbatimTextOutput paired with renderPrint to show the input values as an alternative for demonstration.

library(shiny)

ui <- fluidPage(
  radioButtons(
    "radio", 
    label = HTML(
      '<FONT>Conjoint analysis</FONT>
       <b>How many attributes do you want to insert?</b>'),
    choices = 1:6,
    inline = T
  ),
  uiOutput("input_ui"),
  verbatimTextOutput("text")
)

server <- function(input, output){
  
  output$input_ui <- renderUI({
    lapply(1:input$radio, function(i) {
      splitLayout(
        textInput(paste0("title_", i), label = paste0("Scrivi:", i)),
        selectInput(paste0("lis_", i), label = paste0("Inserisci il numero di livelli:", i), choices = 1:5),
        tags$head(tags$style(HTML("
          .shiny-split-layout > div {
            overflow: visible;
          }
        ")))
      )
    })
  })
  
  output$text <- renderPrint({
    lapply(1:input$radio, function(i) {
      paste(input[[paste0("title_", i)]], input[[paste0("lis_", i)]])
    })
  })
  
}

shinyApp(ui = ui, server = server)

CodePudding user response：

This is my code

library(shiny)

ui <- fluidPage(
   radioButtons(
     "num", 
    label = HTML(
       '<b>Quanti attributi vuoi inserire?</b>'),
    choices = 1:6,
    ),
  uiOutput("input_ui"))

server <- function(input, output){
 
 output$input_ui <- renderUI({                                     
    lapply(1:input$num, function(i) { 
                                      
      splitLayout(
         textInput(paste0("att", i), label = paste0("Attributo ", i)),
        
         radioButtons(
          paste0("liv", i), 
          label = paste0("Inserisci il numero di livelli "),
          choices = 1:5,
          inline = F),
          tags$head(tags$style(HTML(" .shiny-split-layout > div {overflow: visible;} "))),
        )
      
       r<- as.integer(output$liv),
       lapply(1:liv, function(l) {
         textInput(paste0("livello", l), label = paste0("Livello ", l))
       }})})}

shinyApp(ui = ui, server = server)