是否可以根据用户的Internet连接状态启用或禁用整体输入（即开或关）？

Question

我们可以与

RequiredLibraries <- c("shiny", "shinyjs")

RequiredLibraries2Install <- RequiredLibraries[!(RequiredLibraries %in% installed.packages()[, "Package"])]

if(length(RequiredLibraries2Install))   install.packages(RequiredLibraries2Install, dependencies = TRUE)

lapply(RequiredLibraries, library, character.only = TRUE)

is_online <- function(site = "http://www.google.com/")
{
    tryCatch(
    {
        readLines(site,n=1)
        TRUE
    },
    warning = function(w) invokeRestart("muffleWarning"),
    error = function(e) FALSE)
}

ui <- fluidPage(
    useShinyjs(),
    mainPanel(
        tabsetPanel(type = "tabs",
            tabPanel("Reprex",
                checkboxInput(inputId = "Download_Some_Data", label = "Download some data only if there is an Internet connection", value = FALSE, width = '100%')
            )
        ),
        width = 12
    )
)

server <- function(input, output, session)
{
    observeEvent(input[["Download_Some_Data"]],
    {
        toggleState(id = "Download_Some_Data", condition = is_online())
    })
    
    # observe(is_online(),
    # {
        # toggleState(id = "Download_Some_Data", condition = is_online())
    # })
}

runApp(list(ui = ui, server = server), launch.browser = TRUE)

一起使用

httr2::is_online()

来检查互联网：

invalidateLater

Answer 1