Javascript 什么'；我在Shiny中调用message-handler.js有什么问题？

除了通过

messagehandler.js

添加消息框失败之外，我有一个闪亮的应用程序，运行良好

我可以想到一个明显的解释，那就是如果我需要先从某处下载这个message-handler.js文件，但我下面的指南没有提到这一点，当我在谷歌上搜索该文件时，我不知道从哪里下载它。因此，现在我假设它是内置的闪亮

我下面的例子是（模式1）

我的服务器.R脚本是：

# Set options
setwd("tableau_self_serve_portal")

# Connect to Access db
channel <- odbcConnectAccess2007("AD_Users.accdb")

shinyServer(function(input, output, session) {
  # Value of user id
  output$userid <- renderPrint({ input$userid})

  # Value of workbook selection
  output$value <- renderPrint({ input$select })

  observeEvent(input$submission, {
    session$sendCustomMessage(type = 'testmessage', message = 'Thank you for clicking')
    sql <- paste("insert into self_serve_requests (user_name, workbook_to_access, request_date) values(",
                 input$userid,",", input$select,",", Sys.time(),");", sep ="'") 
    cat(sql)
    sqlQuery(channel, sql)
  })  
})

refresh <- F # T = re-pull the AD / Workbook lists from Access DB

# Load libraries
pacman::p_load(RODBC, shiny, shinythemes)

if(refresh){
  users      <- sqlQuery(channel , paste ("select * from aduserlist"))
  workbooks  <- sqlQuery(channel , paste ("select * from public__workbooks"))
  saveRDS(users, "users.RDS")
  saveRDS(workbooks, "workbooks.RDS")
} else{
  users     <- readRDS("users.RDS")
  workbooks <- readRDS("workbooks.RDS")
}

# User Interface
shinyUI(
  fluidRow(
  tags$head(tags$script(src = "message-handler.js")),
  column(4,img(src="leaf-icon.png", align = "top", width = 80)),
  column(8,headerPanel("Tableau Self-serve Portal")),
  fluidPage(
    theme = shinytheme("united"), #"www/bootstrap.css",
  # Copy the line below to make a select box 
  selectizeInput("userid", label = h4("Name of the Requestor"), 
              choices = paste(users$DisplayName), options = list(create = TRUE)
  ),

  # Copy the line below to make a select box 
  selectizeInput("select", label = h4("Workbook(s) to Access"), 
              choices = paste(workbooks$name),
              multiple = T
  ),
  actionButton("submission", "Send Request", style="color: #fff; background-color: #F15C22; border-color: #2e6da4"),
  hr(),
  fluidRow(column(3, verbatimTextOutput("userid"))),
  fluidRow(column(3, verbatimTextOutput("value")))
  )
))

#设置选项
setwd（“表格、自助服务、门户”）
#连接到Access数据库
通道这是找到消息句柄的链接。js@哦，好的，太棒了，谢谢！我把它放在我的www文件夹中，但当我运行应用程序时，仍然没有弹出窗口。