r - 基于 data.table 的闪亮更新图

Question

在我的示例应用程序中，我让用户提供一些输入并在第一个选项卡中从中生成一个 data.table。在第二个选项卡中，我想根据 data.table 显示绘图。我很难让反应正确。不幸的是，此时我得到了error: Operation not allowed without an active reactive context.

请帮助我或给我提示我做错了什么。

数据：

tdata <- data.table(fruit = c("Apple", "Apple", "Apple", "Apple", "Apple", "Apple", "Apple", "Apple","Banana", "Banana","Banana","Banana","Banana", "Banana","Banana","Banana"), 
                    Fertilizer = c(1,2,4,3,2,2,2,2,1,4,3,2,4,4,3,1), 
                    amount = c(2,3,4,7,1,34,33,21,12,32,22,17,14,9,22,6),
                    red = rep(c("+","+","-","-"),4),
                    green = rep(c("+","-"),8))
tdata[, grp := do.call(paste, c(list(sep="\n"),.SD)),.SDcols = 4:5]

用户界面：

library(shiny)
library(data.table)
library(DT)

ui <- (fluidPage(tagList(
  sidebarLayout(
    sidebarPanel(uiOutput("file_input")),
    mainPanel(
      tabsetPanel(
        tabPanel("Data",dataTableOutput('fruit_table') ),
        tabPanel("Plot", plotOutput('barPlot'))

  ))))))

服务器：

server <- function(input, output) {

  fileData <- reactive(
    return(tdata)
  )

  output$file_input <- renderUI ({
    if(is.null(fileData())){
      return()
    }else{
      tagList(
        checkboxGroupInput(inputId = "fruit",
                           label = "fruit",
                           choices = c(unique(fileData()[,get("fruit")])),
                           selected = fileData()[1, 1, with = FALSE]),
        checkboxGroupInput(inputId = "tube",
                           label = "Fertilizer",
                           choices = unique(fileData()[,get("Fertilizer")]),
                           selected = fileData()[1, 3, with = F]),
        ###build checkboxes from Loop:
        lapply(1:(length(fileData())-4), function(i) {
          checkboxGroupInput(inputId = paste0("color",i),
                             label = colnames(fileData()[,i+3, with = FALSE]),
                             choices = c(unique(fileData()[,get(colnames(fileData()[,i+3, with = FALSE]))])),
                             inline = TRUE,
                             selected = fileData()[1, i+3, with = FALSE])
        }))}})

  output$fruit_table <- renderDataTable({
    if(is.null(fileData())){
      return(NULL)
    }else{

      validate(
        need(input$fruit, 'Check at least one fruit'),
        need(input$tube, 'Check at least one Fertilizer'),
        ####loop not working in here
        need(input$color1, "Check at least one !"), 
        need(input$color2, "Check at least one !")
      )

      filter_expr <- TRUE

      if (!(is.null(input$fruit))) {
        filter_expr <- filter_expr & fileData()[,fruit] %in% input$fruit
        #print((input$fruit))
      }
      if (!(is.null(input$tube))) {
        filter_expr <- filter_expr & fileData()[,Fertilizer] %in% input$tube
      }

      ##non-loop-verison
      if (!(is.null(input$color1))) {
        filter_expr <- filter_expr & fileData()[,red] %in% input$color1
      }

      if (!(is.null(input$color2))) {
        filter_expr <- filter_expr & fileData()[,green] %in% input$color2
       }

      datatable(fileData()[filter_expr,],options = list(pageLength = 25))
    }})

  plot.dat <- reactiveValues(main = NULL)
  plot.dat$main <- ggplot(data = fileData(), mapping = aes( x = fileData()[,grp], y =fileData()[,amount]))+
    geom_boxplot( stat = 'boxplot',
                  position = position_dodge(width=0.8),
                  width = 0.55) 
  observe({

    output$barPlot <- renderPlot({
      if(is.null(fileData())){
        return(NULL)
      }else{

        validate(
          need(input$fruit, 'Check at least one fruit'),
          need(input$tube, 'Check at least one Fertilizer'),
          need(input$color1, "Check at least one !"), 
          need(input$color2, "Check at least one !")
        )

        plot.dat$main

  }})
})
}
shinyApp(ui = ui, server = server

)

Answer 1

您需要更新绘制的数据。请参阅以下工作代码。我提取数据以在反应式表达式中进行过滤myFilter。这需要在创建表之前以及创建图之前调用。

library(shiny)
library(data.table)
library(DT)
library(ggplot2)

tdata <- data.table(fruit = c("Apple", "Apple", "Apple", "Apple", "Apple", "Apple", "Apple", "Apple","Banana", "Banana","Banana","Banana","Banana", "Banana","Banana","Banana"), 
                    Fertilizer = c(1,2,4,3,2,2,2,2,1,4,3,2,4,4,3,1), 
                    amount = c(2,3,4,7,1,34,33,21,12,32,22,17,14,9,22,6),
                    red = rep(c("+","+","-","-"),4),
                    green = rep(c("+","-"),8))
tdata[, grp := do.call(paste, c(list(sep="\n"),.SD)),.SDcols = 4:5]



ui <- (fluidPage(tagList(
  sidebarLayout(
    sidebarPanel(uiOutput("file_input")),
    mainPanel(
      tabsetPanel(
        tabPanel("Data",dataTableOutput('fruit_table') ),
        tabPanel("Plot", plotOutput('boxPlot'))

      ))))))

server <- function(input, output) {

  fileData <- tdata # static data, doesn't change, noneed to be reactive

  output$file_input <- renderUI ({
    validate(need(!is.null(fileData), ''))
      tagList(
        checkboxGroupInput(inputId = "fruit",
                           label = "fruit",
                           choices = c(unique(fileData[,get("fruit")])),
                           selected = fileData[1, 1, with = FALSE]),
        checkboxGroupInput(inputId = "tube",
                           label = "Fertilizer",
                           choices = unique(fileData[,get("Fertilizer")]),
                           selected = fileData[1, 3, with = F]),
        ###build checkboxes from Loop:
        lapply(seq(length(fileData)-4), function(i) {
          checkboxGroupInput(inputId = paste0("color",i),
                             label = colnames(fileData[,i+3, with = FALSE]),
                             choices = c(unique(fileData[,get(colnames(fileData[,i+3, with = FALSE]))])),
                             inline = TRUE,
                             selected = fileData[1, i+3, with = FALSE])
        })
      )
  })

  # build a filter according to inputs
  myFilter <- reactive({
     validate(need(!is.null(fileData), ''))
      validate(
        need(input$fruit, 'Check at least one fruit'),
        need(input$tube, 'Check at least one Fertilizer'),
        need(input$color1, "Check at least one !"), 
        need(input$color2, "Check at least one !")
      )

      fileData[,fruit] %in% input$fruit & fileData[,Fertilizer] %in% input$tube &
         fileData[,red] %in% input$color1 & fileData[,green] %in% input$color2

    })

    # print the datatable matching myFilter()
    output$fruit_table <- renderDataTable({
      datatable(fileData[myFilter(),],options = list(pageLength = 25))
    })

  # build a boxPLot according to myFilter()
  output$boxPlot <- renderPlot({
    validate(
      need(!is.null(fileData), ''),
      need(input$fruit, 'Check at least one fruit'),
      need(input$tube, 'Check at least one Fertilizer'),
      need(input$color1, "Check at least one !"),
      need(input$color2, "Check at least one !")
    )

    data <- fileData[myFilter(),]
    ggplot(data = data, mapping = aes( x = data[,grp], y =data[,amount]))+
      geom_boxplot( stat = 'boxplot',
                    position = position_dodge(width=0.8),
                    width = 0.55)
  })
}
shinyApp(ui = ui, server = server)