Why is the sidebar not disappearing when I click the sidebar toggle button?

Question

I changed the width of the sidebar on my Shiny dashboard but when I press the sidebar toggle button, the sidebar doesn't disappear completely.

This is how it looks like after pressing the button:

I am using a .css file and I would like to include a line in this file to solve the problem.

Answer 1

This has to do with shinydashboard passing any custom width parameters provided by the user in the dashboardSidebar() function into some custom CSS. If we provide a minimal reproducible example like so, we can see this in the app if we right click > Inspect.

library(shiny)
library(shinydashboard)

ui <- dashboardPage(
  header = dashboardHeader(),
  body = dashboardBody(),
  sidebar = dashboardSidebar(
    sidebarMenu(),
    width = "10%"
  )
)

server <- function(input, output, session) {}

shinyApp(ui, server)

The red box in the screenshot shows the HTML elements corresponding to the sidebar (note the data-collapsed="true" to indicate the sidebar is currently in its collapsed form). The yellow box shows the CSS styles that control its appearance when collapsed. In this example, we've specified width = "10%" so that is passed to transform: translate(-10%, 0); in the CSS. If we instead add some custom CSS to override this behavior, then the sidebar collapses as normal:

ui <- dashboardPage(
  header = dashboardHeader(),
  body = dashboardBody(),
  sidebar = dashboardSidebar(
    sidebarMenu(),
    width = "10%",
    tags$style(
      "@media (min-width: 768px) {
        .sidebar-collapse .main-sidebar,
        .sidebar-collapse .left-side {
          transform: translate(-100%, 0) !important;
        }
      }"
    )
  )
)

Then the sidebar always fully collapses, e.g., because we've now hard-coded transform: translate(-100%, 0). Again, note the data-collapsed="true" indicating the sidebar has been collapsed. Hope this helps!