ShinyJS toggle applied to shinydashboard box

Question

I'm having issues using shinyjs::toggle.

I have a box displaying selected inputs which I want to show when the user has selected an input and hide when they haven't selected an input.

shinyUI <- function(id) {
checkBoxGroupInput(inputId = "foo",  ......),

div(id=ns("selected_box"),
                    box(
                     width = 24,
                     title = "Selected Foo",
                     textOutput(ns('selected_foo'))))
}

From my understanding, this server code:

shinyjs::toggle(id='selected_box', isTruthy(input$foo)})

Should have an identical effect as this code:

    if(isTruthy(input$foo)) {
      shinyjs::show(id='selected_box', anim = TRUE)
    }
    else {
      shinyjs::hide(id='selected_box', anim = TRUE)
    }
  })

However when I use shinyjs::toggle the selected_box div shows/hides every time the input$foo changes, instead of only when input$foo is empty.

Answer 1

You may want to try conditionalPanel instead

library(shiny)

ui <- fluidPage(
  checkboxGroupInput('foo', "foo", c('a', 'b', 'c')),
  conditionalPanel(
      'typeof input.foo !== "undefined" && input.foo.length > 0',
      textOutput('text')
  )
)

server <- function(input, output, session) {
  output$text <- renderText({"abc"})
}

shinyApp(ui, server)

Alternatively, if you want to use shinyjs, here is the working code

library(shiny)
library(shinyjs)
ui <- fluidPage(
  useShinyjs(),
  checkboxGroupInput('foo', "foo", c('a', 'b', 'c')),
  textOutput('text')
)

server <- function(input, output, session) {
  observeEvent(input$foo, {
      print(is.null(input$foo))
      toggle(id='text', condition = !is.null(input$foo))
  }, ignoreNULL = FALSE)

  output$text <- renderText({"abc"})
}

shinyApp(ui, server)

The problem you have is you need to specify condition = xx argument, the second positional argument is anim not condition, can't be lazy here. Had this same mistake before xD.