Access input$ at ui.R, possible?

[tanthiamhuat]

I know input$radiobutton1 is supposed to be on the server side, and not ui.R.

Say for my case, if I have a radiobutton to choose different languages, e.g English or French.
What I need is when user toggle between those radiobutton, I need the texts to be changed on the ui.R. So how should code for this case?
Thanks.

[nirgrahamuk]

if the ui is dynamic not static/fixed, use uiOutput as its placeholder, and provide renderUI code that dynamically constructs it, you can place a radiobutton in such a way.
https://shiny.rstudio.com/articles/dynamic-ui.html

[nirgrahamuk]

alternatively, you can have a static initial radiobutton, in the normal way, but use an observeEvent that you use to call an updateRadioButtons() function call, to redefine something about the radiobutton

[tanthiamhuat]

hmmm.. interesting.. say for my case, I need to toggle the text below:

fluidRow(column(2,h1('TexttobeToggled')))

how should I use that uiOutput?

[nirgrahamuk]

library(shiny)

ui <- fluidPage(
  fluidRow(column(2,uiOutput("myheader")))
)

server <- function(input, output, session) {
  
  headertext <- reactive('TexttobeToggled')
  
  output$myheader <- renderUI({
    h1(headertext())
  })
}

shinyApp(ui, server)

[tanthiamhuat]

Thanks for the code. Say I am using some kind of translation from https://appsilon.com/internationalization-of-shiny-apps-i18n/, so I would have something like this? But it seems to break the application.

library(shiny.i18n)
ui <- fluidPage(
  fluidRow(column(2,uiOutput("myheader")),
           column(2,column(2,radioButtons('language',"",choices = c("English"="english","Spanish"="spanish"),inline = TRUE)))
  )
)
server <- function(input, output, session) {
  i18n <- Translator$new(translation_json_path = "C:\\xxx\\JSON\\translation.json")
  headertext <- reactive(){
    if (input$language=="english"){
      i18n$set_translation_language("en")
    } else {
      i18n$set_translation_language("sp")
    }
    Test_translated <- i18n$t('Test')
  }
  
  output$myheader <- renderUI({
    h1(headertext())
  })
}
shinyApp(ui, server)

[nirgrahamuk]

You can study https://shiny.rstudio.com/tutorial/written-tutorial/lesson6/ if you aren't familiar with reactives
The following is incorrect syntax

headertext <- reactive(){
         if (input$language=="english"){
               i18n$set_translation_language("en")
         } else {
              i18n$set_translation_language("sp")
         }
         Test_translated <- i18n$t('Test')
     }

rather

headertext <- reactive({
        if (input$language=="english"){
               i18n$set_translation_language("en")
         } else {
              i18n$set_translation_language("sp")
         }
         i18n$t('Test')
     })

Though this assumes you are using Translator correctly , which I'm not familiar with..

[tanthiamhuat]

It is working now, thank you very much for your help.