Question

一个闪亮的应用，它接收用户输入并将列名发送到selectizeInput()框。然后，用户选择几个列名称，并在同一个应用程序的另一个部分/选项卡中创建数据的子集。

该应用的用户界面包含以下部分：

导航栏
导航栏的一个选项卡，用于选择数据和列
用于创建数据子集和绘图的其他选项卡。

ui.R

 library(markdown)
require(XLConnect)


shinyUI(fluidPage(
  # Application title
  img(class = "img-polaroid",
      src = paste0(
      "http://www.aithent.com/wp-content/uploads/2015/05/aithent-website-200x80.png"
    )
  ),
  navbarPage(
    "Project Vanguard",
    tabPanel(
      "Table",
      titlePanel("Select Data"),
      sidebarLayout(
        sidebarPanel(
          selectInput(
            "fileType",
            "Select File Type:",
            c("MS Excel Worksheet (xls,xlsx)" = "xls",
              "Text/CSV (.csv)" = "csv")
          ),
          fileInput(
            'file1',
            'Choose file to upload',
            accept = c(
              'text/csv',
              'text/comma-separated-values',
              'text/tab-separated-values',
              'text/plain',
              '.csv',
              '.tsv',
              'application/vnd.ms-excel',
              'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
              '.xlsx',
              '.xls'
            )
          ),
          tags$hr(),
          checkboxInput('header', 'Header', TRUE),
          radioButtons('sep', 'Separator',
                       c(Comma = ',',
                         Semicolon = ';',
                         Tab = '\t'
                       ),','),
          radioButtons(
            'quote',
            'Quote',
            c(None = '',
              'Double Quote' = '"',
              'Single Quote' = "'"
              ),'"'
          ),
          tags$hr(),
          uiOutput("selector1"),
          uiOutput("selector2")
          ),
        mainPanel(dataTableOutput('table'))
      )),
    tabPanel("Plot",
             sidebarLayout(
               sidebarPanel(radioButtons(
                 "plotType", "Plot type",
                 c("Scatter" = "p", "Line" = "l"))),
               mainPanel(dataTableOutput("ResultTab"),
                         plotOutput("plot")))),
    navbarMenu("More",
               tabPanel(
                 "Summary",
                 verbatimTextOutput("summary"))))
))

server.R

library(sqldf)
options(scipen = 999)
shinyServer(function(input, output, session){
  output$plot <- renderPlot({
    plot(data$Count, data$Sales, type = input$plotType)
  })
  output$summary <- renderPrint({
    summary(data)
  })
  data <- reactive({
    inFile <- input$file1
    if (is.null(inFile))
      return(NULL)
    if (input$fileType == 'csv') {
      table1 <- read.csv(
        inFile$datapath,
        header = input$header,
        sep = input$sep,
        quote = input$quote
      )
      return(table1)
    } else if (input$fileType == 'xls') {
      table1 <- readWorksheetFromFile(inFile$datapath, sheet = 1)
    }
  })

  output$table <- renderDataTable({
    data()
  })

  output$selector1 <- renderUI({
    selectizeInput("GroupVar",
                   "Choose Group Variables:",
                   as.list(colnames(data())),
                   multiple = TRUE)
  })
  output$selector2 <- renderUI({
    selectizeInput("AnalysisVar",
                   "Choose Analysis Variables:",
                   as.list(colnames(data())),
                   multiple = TRUE)
  })

  ResultSet <- reactive({
    Src <- data()
    GVars <- as.character(input$selector1)
    Avars <- as.character(input$selector2)
    gvs <- paste(unlist(strsplit(GVars, ' ')), collapse = ",")
    avs <-
      paste0('sum(',
             strsplit(Avars, ' '),
             ') as SumOf',
             strsplit(Avars, ' '),
             collapse = ",")
    sqlStat <-
      paste0("SELECT ", gvs, ',', avs, " FROM Src GROUP BY ", gvs)
    Result <- sqldf(sqlStat)
    return(Result)
  })
  output$ResultTab <- renderDataTable({
    ResultSet()
  })
})

在代码中，我收到以下错误：

Error in sqliteSendQuery(con, statement, bind.data) : error in statement: near ",": syntax error

我希望知道两件事是我在SQL中的错误，因为： 1.错误的数据传递，即ResultSet的被动Src<-data()中的错误使用情况？要么 2. selectizeInput()语句GVars <- as.character(input$selector1)对AdView adView = new AdView(this); adView.setAdSize(AdSize.BANNER); adView.setAdUnitId(""); parentView.addView(adView); AdRequest adRequest = new AdRequest.Builder().build(); adView.loadAd(adRequest);的引用和使用不当。

Answer 1

要获取用户在selectize中选择的内容，您需要参考id的{{1}}。您应该使用selectizeInput代替input$GroupVar。

您可以在input$selector1中添加print(sqlStat)，以确保您的SQL语句正常。

同样，反应式表达式是闭包，以获得调用它们所需的值。对于你的ResultSet应该是：

renderPlot

如何将数据从一个`reactive（）`传递到R闪亮的另一个？

1 个答案: