Question

我下面有一个简单的闪亮应用程序。在此应用程序中，我希望用户能够上载自己的csv，然后自动将其添加为另一个数据集“ D.B”（由我在原始应用程序中创建）下方的复选框组中。然后，当用户选择文件时，该文件将显示为表格。

在这里，我设法重命名了上载的文件。但是，在保持“更改名称”功能的同时，我无法随后将重命名的表与renderTable()连接。

# Define UI for data upload app ----
    ui <- fluidPage(

      # App title ----
      titlePanel("Uploading Files"),

       # Sidebar layout with input and output definitions ----
      sidebarLayout(

        # Sidebar panel for inputs ----
        sidebarPanel(

           # Input: Select a file ----
           fileInput("file1", "Choose CSV File",
                    multiple = FALSE,
                    accept = c("text/csv",
                           "text/comma-separated-values,text/plain",
                           ".csv")),
          checkboxGroupInput("datasetSelector","Data Files", choices=c("D.B")),
          textInput("filename","Set Filename",value = "Set Name")

        ),

        # Main panel for displaying outputs ----
          mainPanel(

          # Output: Data file ----
          tableOutput("contents")

        ) 
      )
    )
    #server.r
    server <- function(input, output, session) {

      observeEvent(input$filename, {

      req(input$file1)
      Name<-input$filename
      updateCheckboxGroupInput(session,"datasetSelector", choices=c("D.B",Name))
      })

      observeEvent(input$file1, {

        Data<-input$file1$datapath
        Name<-input$filename
        New <- read.csv(Data)
        updateCheckboxGroupInput(session,"datasetSelector", 
          choices=c("D.B",input$file1$name))
      })

      D.B <- reactive({
        if("D.B"%in% input$datasetSelector){
          x <- read.csv("something.csv", stringsAsFactors = F)
        }
      })

      output$contents <- renderTable({
        New
       })
    }

Answer 1

这是一种解决方法。

此解决方案使用闪亮的输入功能来命名列表。在命名列表中，标签是显示名称，而值是返回值。例如。 c("a" = 1, "b" = 2)将在用户界面中显示标签a和b，但将在服务器中返回1和2的值。

由于您希望标签中的一个来自输入，因此有必要分两部分构建有序列表。首先是值，然后是标签。例如。 mylist = c(1,2)设置值，然后names(mylist) = c("a","b")分配标签。

这是我工作的代码：

library(shiny)

# Define UI for data upload app ----
ui <- fluidPage(

  # App title ----
  titlePanel("Uploading Files"),

  # Sidebar layout with input and output definitions ----
  sidebarLayout(

    # Sidebar panel for inputs ----
    sidebarPanel(

      # Input: Select a file ----
      fileInput("file1", "Choose CSV File",
                multiple = FALSE,
                accept = c("text/csv",
                           "text/comma-separated-values,text/plain",
                           ".csv")),
      checkboxGroupInput("datasetSelector","Data Files", choices=c("D.B" = "original")),
      textInput("filename","Set Filename",value = "Set Name")

    ),

    # Main panel for displaying outputs ----
    mainPanel(

      # Output: Data file ----
      tableOutput("contents")

    ) 
  )
)
#server.r
server <- function(input, output, session) {

  observeEvent(input$filename, {

    req(input$file1)
    Name<-input$filename
    # make list
    choices = c("original", "loaded")
    # assign labels to list
    names(choices) = c("D.B", Name)
    updateCheckboxGroupInput(session,"datasetSelector", choices=choices)
  })

  observeEvent(input$file1, {

    Data<-input$file1$datapath
    Name<-input$filename
    New <- read.csv(Data)
    # make list
    choices = c("original", "loaded")
    # assign labels to list
    names(choices) = c("D.B", Name)
    updateCheckboxGroupInput(session,"datasetSelector", choices=choices)
  })

  D.B <- reactive({
    if("D.B"%in% input$datasetSelector){
      x <- read.csv("something.csv", stringsAsFactors = F)
    }
  })

  output_table = reactive({
    if("original" %in% input$datasetSelector)
      return(D.B())
    if("loaded" %in% input$datasetSelector)
      return(read.csv(input$file1$datapath))
  })


  output$contents <- renderTable({
    output_table()
  })
}

# Run the app ----
shinyApp(ui = ui, server = server)

如何处理在闪亮的应用程序中上载和重命名的文件

1 个答案: