Shiny应用点击actionButton添加行正常删除行失效如何解决

问题根因 #

你代码点击删除按钮崩溃的核心是reactiveVal响应式变量的赋值语法错误：
reactiveVal类型变量的取值操作为变量名()，赋值操作需要将新值传入括号，写作变量名(新值)，不能使用<-直接给变量名()赋值。你删除行逻辑中的data() <- data()[-as.numeric(input$TBL1_rows_selected),]不符合语法规则，触发程序崩溃。
你新增行的逻辑通过管道实现赋值虽然可以正常运行，但可读性较差，建议统一为标准写法更便于后续维护。

修复后完整可运行代码 #

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(DT)
library(tibble)
Input <- structure(list(`Security Type` = c("Stock", "Stock", "Load Fund"), Ticker = c("XOM", "NFLX", "AMCPX"), `Purchase Date` = structure(c(
  16070,
  17084, 17084
), class = "Date"), `Sale Date` = structure(c(
  18627,
  NA, 18545
), class = "Date"), `Amount Invested` = c(
  "$10,000",
  "$8,000", "$10,000"
)), class = c(
  "spec_tbl_df", "tbl_df", "tbl",
  "data.frame"
), row.names = c(NA, -3L))
shinyApp(
  ui = tags$body(class = "skin-blue sidebar-mini control-sidebar-open", dashboardPage(
    options = list(sidebarExpandOnHover = TRUE),
    header = dashboardHeader(title = "Investment Advisor Monitoring - Insider Trading", titleWidth = 450),
    sidebar = dashboardSidebar(
      minified = F, collapsed = F,
      selectInput(
        "sectype", "Security Type",
        c(unique(Input$`Security Type`))
      ),
      selectInput(
        "sectick", "Ticker",
        c(unique(Input$Ticker))
      ),
      dateInput("PurDate", "Purchase Date", value = as.Date("2013-12-31")),
      dateInput("selDate", "Sale Date", value = as.Date("2019-01-31")),
      selectInput(
        "aminv", "Amount Invested",
        c(unique(Input$`Amount Invested`))
      ),
      actionButton("add", "Add"),
      actionButton("deleteRows", "Delete Rows")
      
    ),
    body = dashboardBody(
      h3("Results"),
      tabsetPanel(
        id = "tabs",
        tabPanel(
          "InsiderTraining",
          dataTableOutput("TBL1")
        )
      )
    ),
    controlbar = dashboardControlbar(width = 300),
    title = "DashboardPage"
  )),
  server = function(input, output) {
    # 初始化示例数据
    data <- reactiveVal(Input)
    
    observeEvent(input$add, {
      # 读取当前数据新增行后更新响应式变量
      new_data <- data() %>%
        add_row(
          `Security Type` = isolate(input$sectype),
          Ticker = isolate(input$sectick),
          `Purchase Date` = isolate(input$PurDate),
          `Sale Date` = isolate(input$selDate),
          `Amount Invested` = isolate(input$aminv)
        )
      data(new_data)
    })

    observeEvent(input$deleteRows,{
      if (!is.null(input$TBL1_rows_selected)) {
        # 修正为reactiveVal标准赋值语法
        data(data()[-as.numeric(input$TBL1_rows_selected), ])
      }
    })

    output$TBL1 <- renderDataTable(
      data(), selection = "single"
    )
  }
)

内容的提问来源于stack exchange，提问作者firmo23