Server logic for glass tabs

Tracks the active tab and exposes it as a reactive value. Optionally integrates with Shiny's bookmarking system so the active tab is preserved in bookmarked URLs.

Usage

glassTabsServer(id, bookmark = TRUE)

Arguments

id

Module id matching the id passed to glassTabsUI(). Do not wrap this in ns() — glassTabsServer() handles namespacing internally via shiny::moduleServer().

bookmark

Logical. When TRUE (default), registers shiny::onBookmark() and shiny::onRestored() hooks so the active tab is saved and restored automatically when Shiny bookmarking is enabled. Set to FALSE to opt out.

Value

A reactive expression returning the active tab value.

Details

glassTabsServer() follows the same calling convention as all Shiny module server functions: pass the bare module id, not a namespaced one. Inside a parent module, pair it with glassTabsUI(ns("tabs"), ...) in the UI, and call glassTabsServer("tabs") (without ns()) in the server.

Examples

# --- Standalone app ---
if (interactive()) {
  library(shiny)
  ui <- fluidPage(
    useGlassTabs(),
    glassTabsUI(
      "tabs",
      glassTabPanel("a", "A", p("Tab A"), selected = TRUE),
      glassTabPanel("b", "B", p("Tab B"))
    )
  )
  server <- function(input, output, session) {
    active <- glassTabsServer("tabs")
    observe(print(active()))
  }
  shinyApp(ui, server)
}

# --- Bookmarking ---
if (interactive()) {
  library(shiny)
  ui <- function(request) {
    fluidPage(
      useGlassTabs(),
      bookmarkButton(),
      glassTabsUI(
        "tabs",
        glassTabPanel("a", "A", p("Tab A"), selected = TRUE),
        glassTabPanel("b", "B", p("Tab B"))
      )
    )
  }
  server <- function(input, output, session) {
    active <- glassTabsServer("tabs", bookmark = TRUE)
  }
  shinyApp(ui, server, enableBookmarking = "url")
}

# --- Inside a Shiny module ---
# UI side: use ns() to namespace the widget id
my_module_ui <- function(id) {
  ns <- shiny::NS(id)
  shiny::tagList(
    useGlassTabs(),
    glassTabsUI(
      ns("tabs"),                          # <-- ns() wraps the id here
      glassTabPanel("a", "A", p("Tab A"), selected = TRUE),
      glassTabPanel("b", "B", p("Tab B"))
    )
  )
}

# Server side: pass the bare id — NOT ns("tabs")
my_module_server <- function(id) {
  shiny::moduleServer(id, function(input, output, session) {
    active <- glassTabsServer("tabs")     # <-- bare id, no ns()
    shiny::observe(print(active()))
  })
}