Question

在一个闪亮的应用程序的数据表中，我有大约2万张图像。我想删除不喜欢的图像，然后下载生成的数据表（仅包含我想要的图像的路径名）。

我设法看到一个数据框，每一行都显示一张图像。我可以删除不喜欢的行。我现在希望能够将数据框（仅包含文件路径而不是实际图像）下载到csv中。我似乎无法使用downloadHandler做到这一点。我想念什么？

这是我的代码：

server.R

library(shiny)
library(shinydashboard)
library(data.table)
library(DT)
server<-shinyServer(function(input, output) {
  vals<-reactiveValues()
  vals$Data<-data.table(
    df
  )

  output$MainBody<-renderUI({
    fluidPage(
      box(width=12,
          hr(),

          column(12,dataTableOutput("Main_table")),
          tags$script(HTML('$(document).on("click", "input", function () {
                           var checkboxes = document.getElementsByName("row_selected");
                           var checkboxesChecked = [];
                           for (var i=0; i<checkboxes.length; i++) {
                           if (checkboxes[i].checked) {
                           checkboxesChecked.push(checkboxes[i].value);
                           }
                           }
                           Shiny.onInputChange("checked_rows",checkboxesChecked);
  })')),
      tags$script("$(document).on('click', '#Main_table button', function () {
                  Shiny.onInputChange('lastClickId',this.id);
                  Shiny.onInputChange('lastClick', Math.random())
});")

      )
      )
    })



  output$downloadData <- downloadHandler(
    filename = function() {
      paste(input$Main_table, ".csv", sep = "")
    },
    content = function(file) {
      write.csv(vals$Data, file, row.names = FALSE)
    }
  )

  output$Main_table<-renderDataTable({
    DT=vals$Data
    datatable(DT,
              escape=F)}
      )


})

ui.R

ui<-fluidPage(dashboardHeader(disable = T),
                  dashboardSidebar(disable = T),
                  downloadLink("downloadData", "Download"),
                  dashboardBody(uiOutput("MainBody")

                  )
)
# Run the application
shinyApp(ui = ui, server = server)

Answer 1

问题在于def parse_file(filepath): data = [] with open(filepath, 'r') as file_object: row = {} # prepare an empty row for line in file_object: key, match = _parse_line(line) # search for keys in the line if key == 'value_one': value_one = match.group('value_one') value_one = int(value_one) if 'value one' in row: # we always have a full row data.append(row) # append it to the data liest row = {} # and reset it row['value one'] = value_one # we have a match: store the value in row if key == 'value_two': value_two = match.group('value_two') value_two = int(value_two) if 'value two' in row: data.append(row) row = {} row['value two'] = value_two if key == 'value_three': value_three = match.group('value_three') value_three = int(value_three) if 'value three' in row: data.append(row) row = {} row['value three'] = value_three if row != {}: # do not forget the last row data.append(row) data = pd.DataFrame(data) return data是df中的函数。请参阅library(stats)。请不要将?df用作变量名-这只会引起混乱；取df代替。您将此函数包装到DF中，并将其传递到data.table()中（请参阅我添加的reactiveValue）。

此构造被print()视为list()，并且不知道如何处理write.csv()并导致以下错误：

write.table中的错误：'EncodeElement'中未实现的类型'list'

因此，您可能想通过以下方法修复list()初始化传递data.table而不是NULL：

df

此外，您应该修复文件名（library(shiny) library(shinydashboard) library(data.table) library(DT) server <- shinyServer(function(input, output) { vals <- reactiveValues(myTabData = data.table(NULL)) vals$Data <- data.table(df) print(paste("myData:", isolate(vals$Data))) output$MainBody <- renderUI({ fluidPage(box( width = 12, hr(), column(12, dataTableOutput("Main_table")), tags$script( HTML( '$(document).on("click", "input", function () { var checkboxes = document.getElementsByName("row_selected"); var checkboxesChecked = []; for (var i=0; i<checkboxes.length; i++) { if (checkboxes[i].checked) { checkboxesChecked.push(checkboxes[i].value); } } Shiny.onInputChange("checked_rows",checkboxesChecked);})' ) ), tags$script( "$(document).on('click', '#Main_table button', function () { Shiny.onInputChange('lastClickId',this.id); Shiny.onInputChange('lastClick', Math.random())});" ) )) }) output$downloadData <- downloadHandler( filename = function() { "Main_table.csv" }, content = function(file) { write.csv(vals$myTabData, file, row.names = FALSE) # Warning: Error in write.table: unimplemented type 'list' in 'EncodeElement' # write.csv(vals$Data, file, row.names = FALSE) } ) output$Main_table <- renderDataTable({ DT = vals$Data datatable(DT, escape = FALSE) }) }) ui <- fluidPage( dashboardHeader(disable = T), dashboardSidebar(disable = T), downloadLink("downloadData", "Download"), dashboardBody(uiOutput("MainBody")) ) shinyApp(ui = ui, server = server)不存在）

闪亮编辑后如何下载数据表

1 个答案: