R, Shiny, 应用前弹出窗口 [英] R, Shiny, Popup Window before App

问题描述

我正在开发一个闪亮的应用程序，它在启动时访问 MySQL 服务器并从中提取大量数据.这些数据稍后会在应用程序的使用过程中进行过滤.

i am developing a shiny App that accesses a MySQL Server on Launch and pulls a large amount of data from it. This data is later filtered during the use of the App.

由于传输的数据量相当大，第一个查询需要很多时间，这就是为什么我想创建一个对话框/弹出窗口或在应用程序启动时打开的类似内容，并让用户选择预过滤器"的设置，例如仅 2017 年 3 月的数据.

Because of the rather large amounts of data transferred the first query takes a lot of time, this is why i would like to create a Dialog / Popup or something similar that opens at the Launch of the App, and lets the user select Settings for a "pre-filter" e.g. only Data from March 2017.

这可能吗，如果是，怎么做?到目前为止我没有找到任何关于它的信息.

Is this possible and if yes, how to do it? I did not find any info about it so far.

推荐答案

这是实现您想要的一种方法.您只需在服务器函数中执行 showModal(modalDialog()) 即可在启动时显示弹出窗口.有了这些知识，通过使用 reactiveVal 和 observeEvent 来获得你想要的结果是相当简单的.

Here is one way to achieve what you want. You can show a pop-up on startup by simply doing showModal(modalDialog()) in your server function. With this knowledge, it is fairly straightforward to get the result you want by using a reactiveVal and an observeEvent.

我希望这会有所帮助！

library(shiny)
library(dplyr)

ui <- fluidPage(
      dataTableOutput('my_table'),
      actionButton('change','Change query')
)

server <- function(input,output,session)
{
  # the modal dialog where the user can enter the query details.
  query_modal <- modalDialog(
    title = "Important message",
    selectInput('input_query','Select # cyl:',unique(mtcars$cyl)),
    easyClose = F,
    footer = tagList(
      actionButton("run", "Run query")
    )
  )

  # Show the model on start up ...
  showModal(query_modal)

  # ... or when user wants to change query
  observeEvent(input$change,
               {
                 showModal(query_modal)
               })

  # reactiveVal to store the dataset
  my_dataset <- reactiveVal()

  observeEvent(input$run, {
    removeModal()

    # Your query here
    my_data <- mtcars %>% filter(cyl %in% input$input_query)
    my_dataset(my_data)

  })

  # render the output
  output$my_table <- renderDataTable(my_dataset())

}

shinyApp(ui,server)

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