Show all object with renderUI - r

Question

I'm working on a shiny app with dynamic rendering. When the user uncheck the box, he must have an output with 8 wellPanel and when the box is checked, he must have two wellPanel. I used the function renderUI to generate output but when the box is unchecked, I only have 4 wellPanel instead of 8. This is what I did :
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
body <- dashboardBody(
tabItems(
tabItem(tabName = "menutab1",
checkboxInput(inputId = "my_id", "check the box", value = TRUE),
####### renderUI #####
uiOutput("results")
)
)
)
ui <- dashboardPage(
title = "test",
options = list(sidebarExpandOnHover = TRUE),
header = dashboardHeader(disable = FALSE),
sidebar = dashboardSidebar(
minified = TRUE, collapsed = TRUE,
sidebarMenu(id="mymenu",
menuItem("first", tabName = "tab1", icon = icon("fas fa-acorn"),
menuSubItem('menu 1',
tabName = 'menutab1',
icon = icon('fas fa-hand-point-right'))
)
)
),
body
)
############# SERVER ############
server <- function(input, output) {
output$results <- renderUI({
if(input$my_id){
# object 1
fluidRow(
column(6,
wellPanel(
h1("A")
),
br(),
wellPanel(
h1("B")
)
)
)
} else {
# object 2 : doesnt show, why ?
fluidRow(
column(6,
wellPanel(
h1("C")
),
br(),
wellPanel(
h1("D")
)
),
column(6,
wellPanel(
h1("E")
),
br(),
wellPanel(
h1("F")
)
)
)
# object 3 : I only got this
fluidRow(
column(6,
wellPanel(
h1("H")
),
br(),
wellPanel(
h1("I")
)
),
column(6,
wellPanel(
h1("J")
),
br(),
wellPanel(
h1("K")
)
)
)
}
})
}
############# RUN #############
shinyApp(ui = ui, server = server)
How can we fix that ?
Some help would be appreciated

Answer 1

The problem with your above code is, that only the last object of the else statement is returned. You can wrap both fluidRows in a tagList to get the desired output.
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
body <- dashboardBody(tabItems(tabItem(
tabName = "menutab1",
checkboxInput(inputId = "my_id", "check the box", value = TRUE),
uiOutput("results")
)))
ui <- dashboardPage(
title = "test",
options = list(sidebarExpandOnHover = TRUE),
header = dashboardHeader(disable = FALSE),
sidebar = dashboardSidebar(
minified = TRUE,
collapsed = TRUE,
sidebarMenu(
id = "mymenu",
menuItem(
"first",
tabName = "tab1",
icon = icon("fas fa-acorn"),
menuSubItem(
'menu 1',
tabName = 'menutab1',
icon = icon('fas fa-hand-point-right')
)
)
)
),
body
)
server <- function(input, output) {
output$results <- renderUI({
if (input$my_id) {
fluidRow(column(6,
wellPanel(h1("A")),
br(),
wellPanel(h1("B"))
)
)
} else {
tagList(
fluidRow(
column(6,
wellPanel(h1("C")),
br(),
wellPanel(h1("D"))),
column(6,
wellPanel(h1("E")),
br(),
wellPanel(h1("F")))
),
fluidRow(
column(6,
wellPanel(h1("H")),
br(),
wellPanel(h1("I"))),
column(6,
wellPanel(h1("J")),
br(),
wellPanel(h1("K")))
)
)
}
})
}
shinyApp(ui = ui, server = server)