How do i send information from R to JS (Shiny) and use this information as UI?-CodePudding

I want to integrate a button in the header of my shinyapp (which acts as a news button). I want this button to contain information from my then used dataset, so that the user knows there is so-and-so's news (inspired by the way shinyDashboard::notificationItem() does this; just more customized). So I'm looking for a way to output the '5' in my app example as a character in the button, so that the button contains the text: 'News (5)'. Iam very new to JS so i dont know how to even paste 'News' '5'.

The button would then render some new UI with the actuall news, but that is for later.

Thanks for any help!


library(shiny)

ui = navbarPage(title = "Dashboard", 

  tags$script(
    HTML(
      "Shiny.addCustomMessageHandler(
        type = 'num', function(message) {
          var ok = message
          var header = $('.navbar > .container-fluid');
          header.append('<div><input value = ok type = \"button\" class = \"btn action-button\"></div>');
        });"
      
    )
  )
  
)
server = function(input, output, session){
  
  session$sendCustomMessage(type = "num", message = 5)
 
  

}
shinyApp(ui, server)

CodePudding user response：

In JavaScript, one concatenates strings with .

  tags$script(
    HTML(
      "Shiny.addCustomMessageHandler(
        type = 'num', function(message) {
          var ok = 'News ('   message   ')';
          var header = $('.navbar > .container-fluid');
          header.append('<div><button class = \"btn btn-primary action-button\">'   ok   '</button></div>');
        });"
    )
  )

CodePudding user response：

you can also try something like this

ui <- navbarPage("Dashboard",
                 header = tags$script(
                   HTML("var header = $('.navbar > .container-fluid');
                        header.append('<div style=\"float:right; padding-top: 8px\"><button id=\"btn_top\" type=\"button\" class=\"btn btn-primary action-button\" onclick=\"signIn()\">Show me</button></div>')")
                 ),
                tabPanel("Data",
                         radioButtons("select", "choose label", choices = 1:3, inline = T))
)



server <- function(input, output, session) {
  
  observeEvent(input$select, {
    updateActionButton(session,"btn_top", label = paste0("News (", input$select, ")"))
  }, ignoreInit = T)

}

shinyApp(ui, server)