在Shiny中使用selectInput过滤API中的数据

library(shiny)
library(httr)
library(jsonlite)

# 定义UI
ui <- fluidPage(
  titlePanel("API Data Filter"),
  sidebarLayout(
    sidebarPanel(
      selectInput("category", "Select Category:", choices = c("All", "Category1", "Category2", "Category3"))
    ),
    mainPanel(
      tableOutput("data")
    )
  )
)

# 定义服务器逻辑
server <- function(input, output) {
  # 从API获取数据
  data <- reactive({
    response <- GET("https://api.example.com/data")
    content <- content(response, "text")
    json_data <- fromJSON(content)
    return(json_data)
  })
  
  # 根据用户选择过滤数据
  filtered_data <- reactive({
    if (input$category == "All") {
      return(data())
    } else {
      return(data()[data()$category == input$category, ])
    }
  })
  
  # 显示过滤后的数据
  output$data <- renderTable({
    filtered_data()
  })
}

# 运行应用程序
shinyApp(ui = ui, server = server)

data <- reactive({
  tryCatch({
    response <- GET("https://api.example.com/data")
    content <- content(response, "text")
    json_data <- fromJSON(content)
    return(json_data)
  }, error = function(e) {
    showModal(modalDialog(
      title = "Error",
      "Failed to fetch data from the API. Please try again later."
    ))
    return(NULL)
  })
})

data <- reactive({
  response <- GET("https://api.example.com/data")
  content <- content(response, "text")
  json_data <- fromJSON(content)
  
  # 数据验证和清理
  if (!all(c("category", "value") %in% names(json_data))) {
    showModal(modalDialog(
      title = "Error",
      "Invalid data format received from the API."
    ))
    return(NULL)
  }
  
  return(json_data)
})