获取在 Shiny 中使用 grep 触发的事件（生成的输入）

我已生成输入，_1、_2 等...但我想知道触发了哪个事件。

• 有用 ：获取在 Shiny 中触发的事件？ https://stackoverflow.com/questions/56770222/get-the-event-which-is-fired-in-shiny/56771353#56771353

• 有用 ：以闪亮的方式处理多个输入 https://stackoverflow.com/questions/40044768/addressing-multiple-inputs-in-shiny/40045292#40045292

但两者都不起作用.clientdata_output_aFired_hidden and d被解雇。在我的真实应用程序中，隐藏或与反应值链接的其他事件也会触发。

并且没有input$changed它可以工作，但不知道哪个被解雇了。

ui <- fluidPage(
  tags$head(
    tags$script(
      "$(document).on('shiny:inputchanged', function(event) {
          if (event.name != 'changed') {
            Shiny.setInputValue('changed', event.name);
          }
        });"
    )
  ),
  numericInput("a_1", "a_1", 0),
  textInput("a_2", "a_2"),
  textInput("c", "c"),
  textInput("d", "d"),



 p("changedInputs"), textOutput("changedInputs"),br(),
 p("aFired"),textOutput("aFired")
)

server <- function(input, output, session) {
  output$changedInputs <- renderText({
    paste("Outside observer: Latest input fired:", paste(input$changed, collapse = ", "))
  })

  observeEvent({
    lapply(
      (grep(pattern = "a_+[[:digit:]]|c"
      , x = names((input)), value = TRUE)),
      function(x) (input)[[x]]
    )
  }, {
    req(input$changed)
    if (input$changed == "a_1") {
      output$aFired <- renderText("Inside observer: input$a_1 was fired")
    } else  if (input$changed == "a_2") {
      output$aFired <- renderText("Inside observer: input$a_2 was fired")
    } else {
      output$aFired <- renderText((input$changed))
    }
  }, ignoreInit = TRUE)
}

shinyApp(ui, server)

有两个问题需要解决：

1. 你的正则表达式|c caught input$changed
2. 你需要使用isolate(names(input))在事件表达式内，否则观察者将因事件的每次变化而触发names(input)
3. Edit: use isolate({input$changed})- 查看注释（使用时不需要reactiveVal())

ui <- fluidPage(
  tags$head(
    tags$script(
      "$(document).on('shiny:inputchanged', function(event) {
          if (event.name != 'changed') {
            Shiny.setInputValue('changed', event.name);
          }
        });"
    )
  ),
  numericInput("a_1", "a_1", 0),
  textInput("a_2", "a_2"),
  textInput("c", "c"),
  textInput("d", "d"),

  p("changedInputs:"), textOutput("changedInputs"), br(),
  p("aFired:"), textOutput("aFired")
)

server <- function(input, output, session) {
  output$changedInputs <- renderText({
    paste("Outside observer: Latest input fired:", paste(input$changed, collapse = ", "))
  })

  observeEvent(eventExpr = {
    lapply(grep(pattern = "^a_+[[:digit:]]$|^c$", x = isolate({names(input)}), value = TRUE), function(x){input[[x]]})
  }, handlerExpr = {
    req(input$changed)
    if (input$changed == "a_1") {
      output$aFired <- renderText("Inside observer: input$a_1 was fired")
    } else  if (input$changed == "a_2") {
      output$aFired <- renderText("Inside observer: input$a_2 was fired")
    } else {
      output$aFired <- renderText({paste("Inside observer:", isolate({input$changed}), "was fired")})
    }
  }, ignoreInit = TRUE)
}

shinyApp(ui, server)

另一个编辑：现在我记得在哪里isolate({input$changed})迷路了（我确信它在我的测试期间有效......）最初我怀疑renderText()嵌套在观察者内部可能会导致问题，因此我实现了一个reactiveVal()打印输出。该解决方案无需isolate({input$changed}):

ui <- fluidPage(
  tags$head(
    tags$script(
      "$(document).on('shiny:inputchanged', function(event) {
          if (event.name != 'changed') {
            Shiny.setInputValue('changed', event.name);
          }
        });"
    )
  ),
  numericInput("a_1", "a_1", 0),
  textInput("a_2", "a_2"),
  textInput("c", "c"),
  textInput("d", "d"),

  p("changedInputs:"), textOutput("changedInputs"), br(),
  p("aFired:"), textOutput("aFired")
)

server <- function(input, output, session) {
  output$changedInputs <- renderText({
    paste("Outside observer: Latest input fired:", paste(input$changed, collapse = ", "))
  })

  myText <- reactiveVal()

  observeEvent(eventExpr = {
    lapply(grep(pattern = "^a_+[[:digit:]]$|^c$", x = isolate({names(input)}), value = TRUE), function(x){input[[x]]})
  }, handlerExpr = {
    req(input$changed)
    if (input$changed == "a_1") {
      myText("Inside observer: input$a_1 was fired")
    } else  if (input$changed == "a_2") {
      myText("Inside observer: input$a_2 was fired")
    } else {
      myText(paste("Inside observer:", input$changed, "was fired"))
    }
  }, ignoreInit = TRUE)

  output$aFired <- renderText({myText()})

}

shinyApp(ui, server)

在发现实际问题之后并在此处发布我的答案之前，我恢复到了没有的版本reactiveVal()（因为它更接近你的问题）并忘记了isolate。因此，您首先收到的是两个版本的混合版本。