R 使用反应性生成的闪亮对象作为另一个反应性事件的输入

我的闪亮应用程序使用

DT

库呈现动态数据帧。用户可以通过单击来选择所需的行。选择行后，应用程序将以数据帧的形式显示并下载转置的行。但是，在这样做（显示和下载）时，我遇到了如下错误-

错误

警告：[.data.frame:选择了未定义的列[No stack trace available]时出错。

下面是详细的步骤

获取的数据（比如从某个网站获取的数据）

用户通过单击行来选择行，然后单击

actionButton（）

将它们标记为“第一组”

用户清除之前的选择并重复与“步骤-2”相同的步骤来创建第二个组

clean（）函数将转换数据框（行名将变为列名），然后根据用户选择的

row.names（）

对数据框进行子集化

添加注释的可复制代码

库（闪亮）
图书馆（DT）
temp_func您的子集设置错误；
g1
和
g2
是行名，但您在需要列名的
子集中使用了它（因此您得到了错误消息）。因此，我更改了
clean
函数。由于没有堆栈跟踪，因此您的错误消息信息量不大。如果您想获取堆栈跟踪，应使用RStudio中的闪亮应用程序模板（请参见6.2.1末尾）。这样，我就可以

Warnung: Error in [.data.frame: undefined columns selected
  78: stop
  77: [.data.frame
  75: subset.data.frame
  73: clean [C:\Users\jhage\Documents\Programmierung\Shiny_tests\app_2\shinytest7/app.R#12]
  72: observeEventHandler [C:\Users\jhage\Documents\Programmierung\Shiny_tests\app_2\shinytest7/app.R#63]
   1: runApp

因此，调试更容易

更正后的代码：

library(shiny)
library(DT)

temp_func <- function(){
  x <- mtcars
  y = x[,1]
  return(list(complete_df = as.data.frame(x), column1 = as.data.frame(y)))
}

clean <- function(df, g1, g2){
  df_selection <- df[c(which(rownames(df) == g1), which(rownames(df) == g2)),  ]
  df_new <- t(df_selection)
  return(as.data.frame(df_new))
}

# UI
ui <- shinyUI({
  fluidPage(
    actionButton("fetch", label = "Step1-Fetch data first"),
    DT::dataTableOutput("table"),br(),
    tags$h5("Selected for Group-1"), verbatimTextOutput("Group1"),br(),
    tags$h5("Selected for Group-2"),verbatimTextOutput("Group2"),hr(),br(),
    tags$h4("Follow Steps: "),
    actionButton("selG1", label = "Step-2: Mark as  Group-1"),
    actionButton("clear", label = "Step-3: Clear Selection"),
    actionButton("selG2", label = "Step-4: Mark as Group-2"),
    actionButton("cleanIt", "Step-5: Clean Dataframe"),
    DT::dataTableOutput("table2"),
    downloadButton("down", "Step-6: Download cleaned dataframe")
  )})

# Server
server <- Main_Server <- function(input,output,session){
  
  # Reactive Values
  values <- reactiveValues(table = NULL)
  group1 <- reactiveValues(Group1 = NULL)
  group2 <- reactiveValues(Group2 = NULL)
  clean_df <- reactiveValues(df = NULL)
  
  # fetchEvent (Consider temp_func() is fetching data from website)
  observeEvent(input$fetch, {values$table <- temp_func()})
  
  # Rendering table for display
  output$table <- renderDT({datatable(values$table$complete_df)})
  
  # Selection Event (Gorup1)
  observeEvent(input$selG1, {group1$Group1 <- rownames(values$table$complete_df[as.numeric(input$table_rows_selected),])})
  
  # Reset selections
  observeEvent(input$clear, {output$table <- renderDT({datatable(values$table$complete_df)})})
  
  # Selection Event (Gorup1)
  observeEvent(input$selG2, {group2$Group2 <- rownames(values$table$complete_df[as.numeric(input$table_rows_selected),])})
  
  # Print Events
  output$Group1 <- renderPrint({group1$Group1})
  output$Group2 <- renderPrint({group2$Group2})
  
  # observeEvent
  observeEvent(input$cleanIt, {clean_df$df <- clean(values$table$complete_df, group1$Group1, group2$Group2)
  })
  
  # Rendering table for display
  output$table2 <- renderDT({datatable(clean_df$df$df_new)})
  
  # Combined Download
  output$down <- downloadHandler(
    filename = function() { "File.csv"},
    content = function(file) {write.csv(clean_df$df$df_new, file)})
  
}

# Run-app
shinyApp(ui, server)

库（闪亮）
图书馆（DT）
临时函数
library(shiny)
library(DT)

temp_func <- function(){
  x <- mtcars
  y = x[,1]
  return(list(complete_df = as.data.frame(x), column1 = as.data.frame(y)))
}

clean <- function(df, g1, g2){
  df_selection <- df[c(which(rownames(df) == g1), which(rownames(df) == g2)),  ]
  df_new <- t(df_selection)
  return(as.data.frame(df_new))
}

# UI
ui <- shinyUI({
  fluidPage(
    actionButton("fetch", label = "Step1-Fetch data first"),
    DT::dataTableOutput("table"),br(),
    tags$h5("Selected for Group-1"), verbatimTextOutput("Group1"),br(),
    tags$h5("Selected for Group-2"),verbatimTextOutput("Group2"),hr(),br(),
    tags$h4("Follow Steps: "),
    actionButton("selG1", label = "Step-2: Mark as  Group-1"),
    actionButton("clear", label = "Step-3: Clear Selection"),
    actionButton("selG2", label = "Step-4: Mark as Group-2"),
    actionButton("cleanIt", "Step-5: Clean Dataframe"),
    DT::dataTableOutput("table2"),
    downloadButton("down", "Step-6: Download cleaned dataframe")
  )})

# Server
server <- Main_Server <- function(input,output,session){
  
  # Reactive Values
  values <- reactiveValues(table = NULL)
  group1 <- reactiveValues(Group1 = NULL)
  group2 <- reactiveValues(Group2 = NULL)
  clean_df <- reactiveValues(df = NULL)
  
  # fetchEvent (Consider temp_func() is fetching data from website)
  observeEvent(input$fetch, {values$table <- temp_func()})
  
  # Rendering table for display
  output$table <- renderDT({datatable(values$table$complete_df)})
  
  # Selection Event (Gorup1)
  observeEvent(input$selG1, {group1$Group1 <- rownames(values$table$complete_df[as.numeric(input$table_rows_selected),])})
  
  # Reset selections
  observeEvent(input$clear, {output$table <- renderDT({datatable(values$table$complete_df)})})
  
  # Selection Event (Gorup1)
  observeEvent(input$selG2, {group2$Group2 <- rownames(values$table$complete_df[as.numeric(input$table_rows_selected),])})
  
  # Print Events
  output$Group1 <- renderPrint({group1$Group1})
  output$Group2 <- renderPrint({group2$Group2})
  
  # observeEvent
  observeEvent(input$cleanIt, {clean_df$df <- clean(values$table$complete_df, group1$Group1, group2$Group2)
  })
  
  # Rendering table for display
  output$table2 <- renderDT({datatable(clean_df$df$df_new)})
  
  # Combined Download
  output$down <- downloadHandler(
    filename = function() { "File.csv"},
    content = function(file) {write.csv(clean_df$df$df_new, file)})
  
}

# Run-app
shinyApp(ui, server)