将输出对象从Server.R传递到.rmd文件

我正在尝试一个Shinyapp，它以.csv作为输入，计算列的

平均值

，并显示输出。另外，我需要下载

pdf

格式的结果作为报告

问题是，当我运行应用程序时，它工作正常，并在屏幕上显示结果，但当我尝试下载报告时，将抛出错误，说明

不允许Shinyoutput对象。

我遇到的帖子很少，因此无法找到合适的解决方案

下面是我的app.R和report.rmd文件

App.R

library(shiny)
ui <- fluidPage(

sidebarLayout(
  sidebarPanel(
    fileInput("file1", label = (" Choose Data "),multiple = F),
    actionButton("button", "Calculate Mean",style = "background-color : skyblue", 

                 icon = icon("stats", lib = "glyphicon"),width = 250 )

  ),

  # Show a plot of the generated distribution
  mainPanel(
    verbatimTextOutput("avg", placeholder = TRUE),

    downloadButton("reportpdf", label = 'Download Report', 
                   style = "background-color : orange", width = 250)

  )
 )
)


server <- function(input, output) {

  dataframe <- reactive( {

###  Create a data frame reading data file to be used by other functions..
inFile <- input$file1


if (is.null(inFile)){
  createAlert(session, "alert", "exampleAlert", title = "Oops!!!",
              content = "Please select the input file.", append = FALSE)}
else{closeAlert(session, "exampleAlert")}


data <- read.csv(inFile$datapath, header = TRUE)


 })

 avg <- eventReactive(input$button, {mean(dataframe()$A)})
 output$avg <- renderText({avg()})

  output$reportpdf <- downloadHandler(
    filename = function() {
     paste('my-report', sep = '.', 'pdf')
    },


content = function(file) {
  src <- normalizePath('report.Rmd')

  # temporarily switch to the temp dir, in case you do not have write
  # permission to the current working directory
  owd <- setwd(tempdir())
  on.exit(setwd(owd))
  file.copy(src, 'report.Rmd', overwrite = TRUE)

  library(rmarkdown)
  out <- render('report.Rmd', pdf_document())
  file.rename(out, file)
  params <- list(mean = output$avg)
}
 )

 }

 shinyApp(ui = ui, server = server)

---

解决此问题的方法是调用被动函数而不是变量名：

library(shiny)
ui <- fluidPage(

  sidebarLayout(
    sidebarPanel(
      fileInput("file1", label = (" Choose Data "),multiple = F),
      actionButton("button", "Calculate Mean",style = "background-color : skyblue", 

                   icon = icon("stats", lib = "glyphicon"),width = 250 )

    ),

    # Show a plot of the generated distribution
    mainPanel(
      verbatimTextOutput("avg", placeholder = TRUE),

      downloadButton("reportpdf", label = 'Download Report', 
                     style = "background-color : orange", width = 250)

    )
  )
)


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

  dataframe <- reactive( {

    ###  Create a data frame reading data file to be used by other functions..
    inFile <- input$file1


    if (is.null(inFile)){
      createAlert(session, "alert", "exampleAlert", title = "Oops!!!",
                  content = "Please select the input file.", append = FALSE)}
    else{closeAlert(session, "exampleAlert")}


    data <- read.csv(inFile$datapath, header = TRUE)


  })

  avg <- eventReactive(input$button, {mean(dataframe()$A)})

   output$avg <- renderText({avg()})

  output$reportpdf <- downloadHandler(
    filename = function() {
      paste('my-report', sep = '.', 'pdf')
    },


    content = function(file) {
      src <- normalizePath('report.Rmd')

      # temporarily switch to the temp dir, in case you do not have write
      # permission to the current working directory
      owd <- setwd(tempdir())
      on.exit(setwd(owd))
      file.copy(src, 'report.Rmd', overwrite = TRUE)

      library(rmarkdown)
      out <- render('report.Rmd', pdf_document())
      file.rename(out, file)
      params <- list(mean = avg())
    }
  )

}

shinyApp(ui = ui, server = server)

---

相反，您可以使用内联代码

应用程序R

---

希望有帮助

谢谢！！现在我没有得到错误，但是

params$mean

被打印为字符而不是值。我是否必须在

Report.rmd

文件中进行任何更改？再次感谢，它没有打印值，而是打印为

##NULL

，这可能是因为您的平均值计算不正确。如果数据集的平均值是计算出来的，请检查这一部分好吗？屏幕上显示的是平均值，这意味着数据集或计算部分没有问题，我无法确定打印

##NULL

的原因。实际上代码没有变化，我已经从您的答案中复制了相同的代码。最后，非常感谢，它按预期工作。该文件是初学者的综合备忘单。非常感谢。@SBS快乐学习：）

library(shiny)
ui <- fluidPage(

  sidebarLayout(
    sidebarPanel(
      fileInput("file1", label = (" Choose Data "),multiple = F),
      actionButton("button", "Calculate Mean",style = "background-color : skyblue", 

                   icon = icon("stats", lib = "glyphicon"),width = 250 )

    ),

    # Show a plot of the generated distribution
    mainPanel(
      verbatimTextOutput("avg", placeholder = TRUE),

      downloadButton("reportpdf", label = 'Download Report', 
                     style = "background-color : orange", width = 250)

    )
  )
)


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

  dataframe <- reactive( {

    ###  Create a data frame reading data file to be used by other functions..
    inFile <- input$file1


    if (is.null(inFile)){
      createAlert(session, "alert", "exampleAlert", title = "Oops!!!",
                  content = "Please select the input file.", append = FALSE)}
    else{closeAlert(session, "exampleAlert")}


    data <- read.csv(inFile$datapath, header = TRUE)


  })

  avg <- eventReactive(input$button, {mean(dataframe()$A)})

   output$avg <- renderText({avg()})

  output$reportpdf <- downloadHandler(
    filename = function() {
      paste('my-report', sep = '.', 'pdf')
    },


    content = function(file) {
      src <- normalizePath('report.Rmd')

      # temporarily switch to the temp dir, in case you do not have write
      # permission to the current working directory
      owd <- setwd(tempdir())
      on.exit(setwd(owd))
      file.copy(src, 'report.Rmd', overwrite = TRUE)

      library(rmarkdown)
      out <- render('report.Rmd', pdf_document())
      file.rename(out, file)
      params <- list(mean = avg())
    }
  )

}

shinyApp(ui = ui, server = server)

---
 title: " Analysis Report"
 output: pdf_document
 params: mean
  ---
##Analysis Result
Percentage of data points spread: 

```{r}
params$mean
```

library(shiny)
ui <- fluidPage(

sidebarLayout(
sidebarPanel(
  fileInput("file1", label = (" Choose Data "),multiple = F),
  actionButton("button", "Calculate Mean",style = "background-color : skyblue", 

               icon = icon("stats", lib = "glyphicon"),width = 250 )

),

# Show a plot of the generated distribution
mainPanel(
  verbatimTextOutput("avg", placeholder = TRUE),

  downloadButton("reportpdf", label = 'Download Report', 
                 style = "background-color : orange", width = 250)

)
)
)


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

dataframe <- reactive( {

###  Create a data frame reading data file to be used by other functions..
inFile <- input$file1


if (is.null(inFile)){
  createAlert(session, "alert", "exampleAlert", title = "Oops!!!",
              content = "Please select the input file.", append = FALSE)}
else{closeAlert(session, "exampleAlert")}


data <- read.csv(inFile$datapath, header = TRUE)


 })

  avg <- eventReactive(input$button, {mean(dataframe()$A)})

  output$avg <- renderText({avg()})

  output$reportpdf <- downloadHandler(
filename = function() {
  paste('my-report', sep = '.', 'pdf')
},


content = function(file) {
  src <- normalizePath('report.Rmd')

  # temporarily switch to the temp dir, in case you do not have write
  # permission to the current working directory
  owd <- setwd(tempdir())
  on.exit(setwd(owd))
  file.copy(src, 'report.Rmd', overwrite = TRUE)

  library(rmarkdown)
  out <- render('report.Rmd', pdf_document())
  file.rename(out, file)

  }
 )

}

shinyApp(ui = ui, server = server)

---
title: " Analysis Report"
output: pdf_document
params: mean
---
##Analysis Result
Percentage of data points spread: `r mean(dataframe()$A) `