Enable/Disable Radio Buttons

[Alex P]

Dear all,
I am building an app that depends a lot on radion buttons and sliders. I would like to be able to enable disable (grey out?) those based on the current step of the user.

Do you have any idea how I can do that in Shiny?

An example of how my radion buttons and sliders look like below

I would like to thank you for your reply
Regards
Alex
 sidebarLayout(
    sidebarPanel(
   
      radioButtons("FreqRadio", label = h3("Frequency"),
        choices = list("485" = 485, "2600" = 2600,
                       "60000" = 3),selected = 2600),
    
      radioButtons("EnvRadio", label = h3("Environment"),
        choices = list("Urban" = "urban", "Suburban" = "suburban",
                       "Space" = 3),selected = "urban"),
   
    selectInput("PropModel",
          label = "Choose a Propagation Model",
          choices = c("Log Distance", "Erceg HL/FM","Walfish-Ikegami", "Okumura-Hata", "COST 231", "Load"),
          selected = "Percent White"),
    sliderInput("maxDist",
                  "Maximum Distance [m]",
                  min = 10,
                  max = 400,
                  value = 300),   
   

   
conditionalPanel(
      condition = "input.EnvRadio == 'suburban' && input.FreqRadio == '485'",
      sliderInput(
         "TrainingPoints", "Number of Training Points",min=2,max=474,value=100,step=20
        )),

      # Only show this panel if Custom is selected
      conditionalPanel(
         condition = "input.EnvRadio == 'urban'|| input.FreqRadio == '2600'",
         sliderInput("TrainingPoints", "Number of Training Points", min=2, max=924, value=200,step=20)
      )

    ),

[Dean Attali]

Hi Alex, since this is a very common question, I built a package called shinyjs that can disable/enable buttons.

Here's how to use it to disable/enable a radio 

library(shiny)

library(shinyjs)

runApp(shinyApp(

  ui = fluidPage(

    useShinyjs(),

    radioButtons("radios", "Options", 1:5),

    actionButton("off", "Disable"),

    actionButton("on", "Enable")

  ),

  server = function(input, output, session) {

    observeEvent(input$off, {

      disable("radios")

    })

    observeEvent(input$on, {

      enable("radios")

    })

  }

))

Or if you want to enable/disable based on a condition, you can use something like this

library(shiny)

library(shinyjs)

runApp(shinyApp(

  ui = fluidPage(

    useShinyjs(),

    radioButtons("radios", "Options", 1:5),

    textInput("text", "Buttons will be enabled when more than 3 characters are typed")

  ),

  server = function(input, output, session) {

    observeEvent(input$text, {

      toggleState("radios", nchar(input$text) > 3)

    })

  }

))

I apologize I didn't read your specific code but I hope you can use these simple examples to make it work on your code

[Alex P]

Thanks.
This has helped considerably.
The problem is how to add the events that enable disable components.
For example the following gives me a syntax error

 tabPanel("All_Data", fluidRow(
                     column(12,
               observeEvent(input$off, {
                disable("radios")
                }),
                           plotOutput("ShadowDistPlot",height=900,width=900), tableOutput('table'),
                           plotOutput("Variog",height=900), actionButton('goTable', 'Go table')))),


I wanted when the user clicks on the specific tabPanel that action to disable me specific options from my left panel.
Is that possible?
Regards
Alex

[Dean Attali]

The code to enable/disable the buttons is server-side logic, it should be in the server function, not in the UI.

I don't remember the code off the top of my head, but for you case you just need to write a reactive that gets fired when the tab changes. I'm sure there are many examples of people doing that.  Something like "observe({ if(input$all_tabs == "All_Data") disable("radios") }). That code won't work, you have to find out how to perform an action when a tab changes, there should be plenty online