无法根据用户输入过滤RShiny中的标记

library(shiny)

# 定义UI
ui <- fluidPage(
  textInput("filter_input", "过滤条件："),
  actionButton("filter_button", "过滤"),
  tableOutput("filtered_table")
)

# 定义服务器逻辑
server <- function(input, output) {
  # 模拟数据
  data <- data.frame(
    Name = c("John", "Jane", "Mike"),
    Age = c(25, 30, 35),
    Gender = c("Male", "Female", "Male")
  )
  
  # 过滤函数
  filter_data <- function(data, filter) {
    if (is.null(filter) || filter == "") {
      return(data)
    } else {
      return(data[grep(filter, data$Name), ])
    }
  }
  
  # 过滤按钮点击事件
  observeEvent(input$filter_button, {
    filtered_data <- filter_data(data, input$filter_input)
    output$filtered_table <- renderTable(filtered_data)
  })
}

# 运行应用程序
shinyApp(ui, server)