使用R Shiny checkboxGroupInput為DT:：dataTableOutput選擇列

我是Shiny的新手。我正在開(kāi)發(fā)一個(gè)應(yīng)用程序，該應(yīng)用程序連接到數(shù)據(jù)庫(kù)并提取一組數(shù)據(jù)，然后讓用戶(hù)通過(guò)一系列selectInput“向下搜索”，然后最終允許他們下載.csv結(jié)果。下載部分很重要。數(shù)據(jù)太大，無(wú)法讓DT用server=false來(lái)渲染所有數(shù)據(jù)，所以我需要維護(hù)過(guò)濾后的dataframe，這樣我就可以用自己的下載處理程序而不是DT按鈕來(lái)write.csv()它。

下面這個(gè)最小的例子不起作用，但希望能清楚地說(shuō)明我想做什么。

library(shiny)
library(DT)
library(magrittr)

ids <- c(1, 2, 3, 4, 5)
firstNames <- c("Bob", "Jane", "Jim", "Billy", "Siouxsie")
lastNames <- c("Smith", "Jones", "Thomas", "Idol", "Sioux")
FaveColors <- c("Blue", "Green", "Yellow", "Red", "Black")
df <- data.frame(ids, firstNames, lastNames, FaveColors)

# Define UI 
ui <- fluidPage(

    # Application title
    titlePanel("Minimal Example"),

    # Sidebar 
    sidebarLayout(
        sidebarPanel(
            tabPanel("Columns",
                      checkboxGroupInput(inputId = "ColumnsToShow", label = "Output Columns",
                                         choices = names(df)
                      )
            )
        ),

        # Show a table
        mainPanel(
          DT::dataTableOutput("FilteredDataFrame")
        )
    )
)

# Define server logic 
server <- function(input, output) {
  
  filtered_df <- reactive({
    #THIS DOESN'T WORK :)
    temp_frame <- df %>% select(input$Columns)
    return(temp_frame)
  })

  output$FilteredDataFrame <- DT::renderDT(server=TRUE, {datatable(filtered_df(), extensions = 'Buttons',
                                                                   options = list(scrollx=TRUE,
                                                                                  lengthMenu = c(10,20,30),
                                                                                  paging = TRUE,
                                                                                  searching = TRUE,
                                                                                  fixedColumns = TRUE,
                                                                                  autoWidth = TRUE,
                                                                                  ordering = TRUE,
                                                                                  #dom = 'Bfrtip',
                                                                                  dom = 'tlip',
                                                                                  buttons = c('copy', 
                                                                                              'csv',
                                                                                              'excel')
                                                                   )
  )
  }
  )
}

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