为了完整起见,这是我编写的代码。这是从引用的猪排链接中收集到的。它有效,尽管有些部分我仍然不明白。
library(shiny)
Logged = FALSE;
ui1 <- function(){
tagList(
div(id = "login",
wellPanel(textInput("name", "Name"),
br(),actionButton("submit", "Submit"))),
tags$style(type="text/css", "#login {font-size:10px; text-align: left;position:absolute;top: 40%;left: 50%;margin-top: -100px;margin-left: -150px;}")
)}
ui2 <- function(){fluidPage(
# Application title
titlePanel({
fluidRow(column(12,
textOutput("greeting")))
})
)}
ui = (htmlOutput("page"))
server = (function(input, output,session) {
USER <- reactiveValues(Logged = Logged)
observe({
if (USER$Logged == FALSE) {
if (!is.null(input$submit)) {
if (input$submit > 0) {
Username <- isolate(input$name)
if (length(Username) > 0 ) {
USER$Logged <- TRUE
}
}
}
}
})
observe({
if (USER$Logged == FALSE) {
output$page <- renderUI({
div(class="outer",do.call(bootstrapPage,c("",ui1())))
})
}
if (USER$Logged == TRUE)
{
output$page <- renderUI({
div(class="outer",do.call(fluidPage,ui2()))
})
print(ui)
}
})
output$greeting <- renderText({
print(paste("Hello, how are you", " ", input$name,"?", sep = ""))
})
})
runApp(list(ui = ui, server = server))