如何在上传另一数据时从闪亮中删除一个数据

Question

为了通过最小的示例来说明我的问题，让我们考虑下面的代码（作为完全可重现的示例）。

library(shiny)

ui <- fluidPage(
  fileInput("upload", NULL, accept = c(".csv", ".tsv")),
  numericInput("n", "Rows", value = 5, min = 1, step = 1),
  tableOutput("head"),
  fileInput("upload2", NULL, accept = c(".csv", ".tsv")),
  numericInput("n2", "Rows", value = 5, min = 1, step = 1),
  tableOutput("head2")
)

server <- function(input, output, session) {
  data <- reactive({
    req(input$upload)
    
    ext <- tools::file_ext(input$upload$name)
    switch(ext,
           csv = vroom::vroom(input$upload$datapath, delim = ","),
           tsv = vroom::vroom(input$upload$datapath, delim = "\t"),
           validate("Invalid file; Please upload a .csv or .tsv file")
    )
  })
  
  output$head <- renderTable({
    head(data(), input$n)
  })
  
  data2 <- reactive({
    
    req(input$upload2)
    
    ext <- tools::file_ext(input$upload2$name)
    switch(ext,
           csv = vroom::vroom(input$upload2$datapath, delim = ","),
           tsv = vroom::vroom(input$upload2$datapath, delim = "\t"),
           validate("Invalid file; Please upload a .csv or .tsv file")
    )
  })
  
  output$head2 <- renderTable({
    head(data2(), input$n2)
  })
  
}

shinyApp(ui, server)

应用程序要求用户上传数据集，然后询问行数并显示上传数据的

head()

。还有一个类似的界面。

现在我的要求是，每当闪亮的应用程序用户上传

data2

时，应将

data

从环境中删除，并且摘要也应删除；如果显示

data2

信息，则数据反之亦然。

我尝试了很多方法，例如使用

observeEvent

，

eventReactive

等，但我无法做到。请推荐。

Answer 1

试试这个

library(shiny)
library(shinyjs)

ui <- fluidPage(
  useShinyjs(),
  fileInput("upload", NULL, accept = c(".csv", ".tsv")),
  numericInput("n", "Rows", value = 5, min = 1, step = 1),
  tableOutput("head"),
  fileInput("upload2", NULL, accept = c(".csv", ".tsv")),
  numericInput("n2", "Rows", value = 5, min = 1, step = 1),
  tableOutput("head2")
)

server <- function(input, output, session) {
  data <- reactive({
    req(input$upload)
    
    ext <- tools::file_ext(input$upload$name)
    switch(ext,
           csv = vroom::vroom(input$upload$datapath, delim = ","),
           tsv = vroom::vroom(input$upload$datapath, delim = "\t"),
           validate("Invalid file; Please upload a .csv or .tsv file")
    )
  })
  
  output$head <- renderTable({
    head(data(), input$n)
  })
  
  data2 <- reactive({
    
    req(input$upload2)
    
    ext <- tools::file_ext(input$upload2$name)
    switch(ext,
           csv = vroom::vroom(input$upload2$datapath, delim = ","),
           tsv = vroom::vroom(input$upload2$datapath, delim = "\t"),
           validate("Invalid file; Please upload a .csv or .tsv file")
    )
  })
  
  observeEvent(input$upload, {
    shinyjs::hide("head2")
    shinyjs::show("head")
  })

  observeEvent(input$upload2, {
    shinyjs::hide("head")
    shinyjs::show("head2")
  })
  
  output$head2 <- renderTable({
    head(data2(), input$n2)
  })
  
}

shinyApp(ui, server)