我的代码：

Question

我想在开头添加一个新类别，它将选择表格的列。我无法将变量与应用程序中的其他元素组合在一起。有人可以向我解释我做错了什么吗？正如您在图形程序中看到的那样效果不佳。

我的代码：

 library(shiny)

data <- data.frame(
  Category1 = rep(letters[1:3], each = 15),
  Info = paste("Text info", 1:45),
  Category2 = sample(letters[15:20], 45, replace = T),
  Size = sample(1:100, 45),
  MoreStuff = paste("More Stuff", 1:45)
)
ui <- fluidPage(titlePanel("Test Explorer"),
                sidebarLayout(
                  sidebarPanel(
                    selectizeInput(
                      "show_vars",
                      "Columns to show:",
                      choices = colnames(data),
                      multiple = TRUE,
                      selected = c("Category1", "Info", "Category2")
                    ),
                    uiOutput("category1"),
                    uiOutput("category2"),
                    uiOutput("sizeslider")
                  ),
                  mainPanel(tableOutput("table"))
                ))

server <- function(input, output, session) {
  data2 <- reactive({
    req(input$table)
    if (input$table == "All") {
      return(data)
    }
    data[, names(data) %in% input$show_vars]
  })

  output$category1 <- renderUI({
    selectizeInput('cat1',
                   'Choose Cat 1',
                   choices = c("All", sort(as.character(
                     unique(data$Category1)
                   ))),
                   selected = "All")
  })

  df_subset <- eventReactive(input$cat1, {
    if (input$cat1 == "All") {
      df_subset <- data
    }
    else{
      df_subset <- data[data$Category1 == input$cat1, ]
    }
  })

  df_subset1 <- reactive({
    if (is.null(input$cat2)) {
      df_subset()
    } else {
      df_subset()[df_subset()$Category2 %in% input$cat2, ]
    }
  })

  output$category2 <- renderUI({
    selectizeInput(
      'cat2',
      'Choose Cat 2 (optional):',
      choices = sort(as.character(unique(
        df_subset()$Category2
      ))),
      multiple = TRUE,
      options = NULL
    )
  })

  output$sizeslider <- renderUI({
    sliderInput(
      "size",
      label = "Size Range",
      min = min(df_subset1()$Size),
      max = max(df_subset1()$Size),
      value = c(min(df_subset1()$Size), max(df_subset1()$Size))
    )
  })

  df_subset2 <- reactive({
    if (is.null(input$size)) {
      df_subset1()
    } else {
      df_subset1()[df_subset1()$Size >= input$size[1] &
                     df_subset1()$Size <= input$size[2], ]
    }
  })

  output$table <- renderTable({
    df_subset2()
  })
}

shinyApp(ui, server)

Answer 1

您的代码几乎没有问题

您在data2()中存储了列选择的无效值，并显示了表df_subset2()。与您的代码一样，当您添加列并选择Cat1下拉列表时，列会发生更改，因为其值取决于data.react。
避免使用data等通用名称来存储数据。有时会干扰R基本名称
当您希望UI上的更改能够反映时，您需要使用ObserveEvent和eventReactive

以下是我修复的内容，您可以相应更改。

添加了提交按钮
将输入选择代码包装到ObserveEvent 这样，只有在单击“提交”按钮时才会显示数据。

这是代码。

library(shiny)

data.input <- data.frame(
  Category1 = rep(letters[1:3], each = 15),
  Info = paste("Text info", 1:45),
  Category2 = sample(letters[15:20], 45, replace = T),
  Size = sample(1:100, 45),
  MoreStuff = paste("More Stuff", 1:45)
)

<强> ui.r

ui <- fluidPage(titlePanel("Test Explorer"),
                sidebarLayout(
                  sidebarPanel(
                    selectizeInput(
                      "show_vars",
                      "Columns to show:",
                      choices = colnames(data.input),
                      multiple = TRUE,
                      selected = c("Category1", "Info", "Category2")
                    ),
                    actionButton("button", "An action button"),
                    uiOutput("category1"),
                    uiOutput("category2"),
                    uiOutput("sizeslider")
                  ),
                  mainPanel(tableOutput("table"))
                ))

<强> server.r

server <- function(input, output, session) {
  data.react <- eventReactive(input$button, {
    data.input[, input$show_vars]
  })
  observeEvent(input$button, {
    output$category1 <- renderUI({
      data.sel <- data.react()
      selectizeInput('cat1',
                     'Choose Cat 1',
                     choices = c("All", sort(as.character(
                       unique(data.sel$Category1)
                     ))),
                     selected = "All")
    })

    df_subset <- eventReactive(input$cat1, {
      data.sel <- data.react()
      if (input$cat1 == "All") {
        data.sel
      }
      else{
        data.sel[data.sel$Category1 == input$cat1,]
      }
    })

    output$category2 <- renderUI({
      selectizeInput(
        'cat2',
        'Choose Cat 2 (optional):',
        choices = sort(as.character(unique(
          df_subset()$Category2
        ))),
        multiple = TRUE,
        options = NULL
      )
    })

    df_subset1 <- reactive({
      if (is.null(input$cat2)) {
        df_subset()
      } else {
        df_subset()[df_subset()$Category2 %in% input$cat2,]
      }
    })

    output$sizeslider <- renderUI({
      sliderInput(
        "size",
        label = "Size Range",
        min = min(data.input$Size),
        max = max(data.input$Size),
        value = c(min(data.input$Size), max(data.input$Size))
      )
    })

    df_subset2 <- reactive({
      if (is.null(input$size)) {
        df_subset1()
      } else {
        df_subset1()[data.input$Size >= input$size[1] &
                       data.input$Size <= input$size[2],]
      }
    })
    output$table <- renderTable({
      df_subset2()

    })
  })
}

shinyApp(ui, server)

在Shiny中选择表格的列

我的代码：

1 个答案: