Navbar items

The navbar of a dock board is drawn from a navbar_items collection, the dock's own controls included. An item is created by navbar_item(), items are combined with c(), [ reorders or drops them by id and [[ extracts one. An app hands the navbar to blockr.core::serve() as navbar, a function of the board and its plugins that returns the items, as it does plugins and options.

Usage

navbar_item(id, ui, server = NULL, fill = FALSE, shrink = FALSE)

is_navbar_item(x)

is_navbar_items(x)

plugin_navbar_item(plugin)

default_navbar_items(x, plugins)

blockr_app_navbar(x, plugins)

custom_navbar(x)

Arguments

id

Item id, unique within the navbar

ui

A function called as ui(id, board) with id as NS(board_id, item_id) and the board, returning the item's UI, or NULL to leave the item out of the bar

server

NULL or a function called as server(id, board) with the item id and the board's reactive values, once per session, from the board server, so that a shiny::moduleServer() it starts shares the UI's namespace

fill

Whether the item takes up the free space of the bar

shrink

Whether the item gives way first on a narrow bar. The items with neither fill nor shrink keep their width.

x

Object. For default_navbar_items() and blockr_app_navbar(), the board, and for custom_navbar(), the items to append: a navbar_item, a navbar_items collection or a list of items.

plugin

A board plugin, or NULL

plugins

Board plugins

Value

The constructor navbar_item() returns a navbar_item object, and so does plugin_navbar_item(), unless its plugin is NULL, which returns NULL. The functions default_navbar_items() and blockr_app_navbar() return a navbar_items collection, as do c() and [ on items, and custom_navbar() returns a function of the board and its plugins that returns one. The checks is_navbar_item() and is_navbar_items() return a boolean.

Details

The default items, returned by default_navbar_items(), are, in order: the piece the preserve_board plugin draws (id "preserve_board"), a spacer ("spacer"), the busy indicator ("busy"), the view menu ("views"), the read-only indicator ("read_only"), drawn only on a locked board, and the board options ("options"). The generic blockr_app_navbar() gives the default by board class, and custom_navbar() returns a navbar function that appends a fixed set of items to it, dropping any default item that shares an id with one of them. A plugin's piece is placed by plugin_navbar_item(), which the defaults use for the preserve_board plugin.

An item whose ui draws a single shiny::uiOutput() or shiny::textOutput() takes no room in the bar while that output is empty, as an avatar would with nobody signed in.

Examples

help <- navbar_item(
  "help",
  function(id, board) {
    shiny::tags$a(
      href = "https://bristolmyerssquibb.github.io/blockr.dock/",
      "Help"
    )
  }
)

brd <- new_dock_board()
items <- c(default_navbar_items(brd, blockr.core::board_plugins(brd)), help)
names(items)
#> [1] "preserve_board" "spacer"         "busy"           "views"         
#> [5] "read_only"      "options"        "help"          
names(items[c("help", "options")])
#> [1] "help"    "options"

if (interactive()) {
  blockr.core::serve(brd, navbar = custom_navbar(help))
}