Question

我的代码能够上传csv /文本文件，但是当我按下“清理”操作按钮时却无法清理数据。我不确定是什么问题，当我在数据表和数据帧形式中都无法正常工作时。我的代码的目的是让用户：

上传文件
按清理以清理数据
下载已清理的文件

我们将不胜感激！

数据表形式：

library(data.table)
library(DT)
runApp(shinyApp(

  ui=(fluidPage(
  titlePanel("Clean your data!"),

  mainPanel(
    fileInput("file", "Upload file"),
    actionButton("Go", "Clean!"),

    DT::dataTableOutput("df_data_out"),
    downloadButton("downloadData","Download")
  )
)),
server <- function(input, output){
  myData <- reactive({
    inFile <- input$file
    if (is.null(inFile)) return(NULL)
    data <- read.csv(inFile$datapath, header = TRUE)
    data <- as.data.table(data)
  })
  eventReactive(input$Go, {
    dt <- myData()
    dt <- as.data.table(dt)
    dt1 <- dt[, splitletter:=substr(DocRef,1,1)]
    dt2 <- dt1[splitletter == "B" | splitletter == "I"]
    dt3 <- dt2[DocDate <= 20171231 & DocDate >= 20160101]
    dt3 <- dt3[AcCurWTaxAmt>0 & HomeWTaxAmt<0, 
    HomeWTaxAmt:=abs(HomeWTaxAmt)]
    dt3 <- dt3[AcCurWTaxAmt<0 & HomeWTaxAmt>0, HomeWTaxAmt:=HomeWTaxAmt* 
(-1)]
    dt3 <- dt3[AcCurWTaxAmt==0 & HomeWTaxAmt!=0, HomeWTaxAmt:=0]
    dt3 <- dt3[AcCurWTaxAmt!=0 & HomeWTaxAmt==0, HomeWTaxAmt:=NA]
    dt4 <- na.omit(dt3)
    dt4 <- dt4[, AcCrAmt := AcCrIsMinus1 * AcCurWTaxAmt]
    dt4 <- dt4[, splitletter:= NULL]
  })
  output$df_data_out <- DT::renderDataTable({
    DT::datatable(myData())})
  output$downloadData <- downloadHandler(

    filename = function() { 
      paste("data-", Sys.Date(), ".csv", sep="")
    },
    content = function(file) {
      write.csv(myData(), file)
    })

}))

数据框形式：

runApp(shinyApp(
  ui=(fluidPage(
    titlePanel("Clean your data!"),

    mainPanel(
      fileInput("file", "Upload file"),
      actionButton("Go", "Clean!"),

      tableOutput("df_data_out"),
      downloadButton("downloadData","Download")
    )
  )),
  server <- function(input, output){
    myData <- reactive({
      inFile <- input$file
      if (is.null(inFile)) return(NULL)
      df_data <- read.csv(inFile$datapath, header = TRUE)
      df_data <- as.data.frame(df_data)
    })     
    eventReactive(input$Go, {
      dt <- myData()
      dt <- as.data.frame(data)
      dt1[, splitletter] <- substr(dt$DocRef,1,1)
      dt2 <- (dt1$splitletter == "B" | dt1$splitletter == "I")
      dt3 <- (dt2$DocDate <= 20171231 & dt2$DocDate >= 20160101)
      while(dt3$AcCurWTaxAmt>0 & dt$HomeWTaxAmt<0){
        dt3$HomeWTaxAmt <- abs(dt3$HomeWTaxAmt)   
      }
      while(dt3$AcCurWTaxAmt<0 & HomeWTaxAmt>0){
        dt3$HomeWTaxAmt <- dt3$HomeWTaxAmt*(-1)
      }
      while(dt3$AcCurWTaxAmt==0 & HomeWTaxAmt!=0){
        dt3$HomeWTaxAmt <- 0
      } 
      while(dt3$AcCurWTaxAmt!=0 & HomeWTaxAmt==0){
        dt3$HomeWTaxAmt<- NA
      } 
      dt3 <- na.omit(dt3)
      dt3[,AcCrAmt] <- dt3$AcCrIsMinus1 * dt3$HomeWTaxAmt
      dt3$splitletter <- NULL
    })

   output$df_data_out <- renderTable({
     myData()
   })
   output$downloadData <- downloadHandler(

      filename = function() { 
        paste("data-", Sys.Date(), ".csv", sep="")
      },
      content = function(file) {
        write.csv(myData(), file)
      })
}))

Answer 1

下面是一个有效的示例。使用CSV作为输入来复制内容非常困难，因为我们不知道您喜欢什么。此外，您在eventReactive中按名称引用列，因此我假设您始终向其传递特定的CSV。

eventReactive很好，它是一个反应函数，只需要它也需要一个触发它的表达式。因此，它会像reactive一样返回反应式表达式。您正在尝试像eventReactive那样使用observeEvent。

当人们单击按钮eventReactive时，将触发该按钮并返回您不使用的reactive。 reactive表达式对象myData保持不变。如果您未在任何输出中使用eventReactive的输出（即output$df_data_out），则反应式将永远不会运行...

还请注意，您的reactive表达式没有明确的return。

library(shiny)

ui <- fluidPage(
  selectInput("select", "select data", choices = c("cars", "iris")),
  actionButton("clean", "Clean data"),
  fluidRow(
    column(6, tableOutput("original")),
    column(6, tableOutput("cleaned"))
  )
)

server <- function(input, output, session) {

  orig_data <- reactive({
    if(input$select == "cars")
      return(cars)
    else
      return(iris)
  })

  cleaned_data <- eventReactive(input$clean, {
    orig_data() %>% 
      head(5)
  })

  output$original <- renderTable({
    orig_data()
  })

  output$cleaned <- renderTable({
    cleaned_data()
  })

}

shinyApp(ui, server)

Shiny App中的数据清理操作按钮不起作用

1 个答案: