模块中使用的observeEvent Shiny 函数不起作用 [英] observeEvent Shiny function used in a module does not work

问题描述

我正在开发一个应用程序，在该应用程序中我使用模块来显示不同选项卡的 ui 内容.但是，该模块似乎不与主(或父)应用程序通信.它会显示正确的 ui，但在单击 actionButton 时无法执行 observeEvent 函数，它应该更新当前选项卡并显示第二个选项卡.

I'm developing an app in which I use modules to display different tab's ui content. However it seems like the module does not communicate with the main (or parent) app. It displays the proper ui but is not able to execute the observeEvent function when an actionButton is clicked, it should update the current tab and display the second one.

在我的代码中，我创建了一个命名空间函数并将 actionButton 的 id 包裹在 ns() 中，但是它仍然不起作用.有谁知道怎么回事?

In my code I have created a namespace function and wrapped the actionButton's id in ns(), however it still does not work. Does anyone knows what's wrong?

library(shiny)

moduleUI <- function(id){

  ns <- NS(id)
      sidebarPanel(

        actionButton(ns("action1"), label = "click")
      )
}

module <- function(input, output, session){


  observeEvent(input$action1, {
    updateTabItems(session, "tabsPanel", "two")
  })
}

ui <- fluidPage(

            navlistPanel(id = "tabsPanel",

                         tabPanel("one",moduleUI("first")),
                         tabPanel("two",moduleUI("second"))
))
server <- function(input, output, session){
  callModule(module,"first")
  callModule(module,"second")

}

shinyApp(ui = ui, server = server)

推荐答案

observeEvent 有效，但由于模块只看到和知道作为输入参数提供给它们的变量，它不知道指定的 tabsetPanel，因此无法更新它.这个问题可以使用反应值来解决，该值作为参数传递并在模块内部更改.一旦它被改变，它就会被主应用知道并且可以更新 tabsetPanel:

The observeEvent works, but since modules only see and know the variables given to them as input parameters, it does not know the tabsetPanel specified and thus cannot update it. This problem can be solved using a reactive Value, which is passed as parameter and which is changed inside the module. Once it's changed, it is known to the main app and can update the tabsetPanel:

library(shiny)
library(shinydashboard)

moduleUI <- function(id){

  ns <- NS(id)
  sidebarPanel(
    actionButton(ns("action1"), label = "click")
  )
}

module <- function(input, output, session, tabsPanel, openTab){

  observeEvent(input$action1, {
    if(tabsPanel() == "one"){  # input$tabsPanel == "one"
      openTab("two")
    }else{                     # input$tabsPanel == "two"
      openTab("one")
    }
  })

  return(openTab)
}

ui <- fluidPage(
  h2("Currently open Tab:"),
  verbatimTextOutput("opentab"),
  navlistPanel(id = "tabsPanel",
               tabPanel("one", moduleUI("first")),
               tabPanel("two", moduleUI("second"))
  ))


server <- function(input, output, session){
  openTab <- reactiveVal()
  observe({ openTab(input$tabsPanel) }) # always write the currently open tab into openTab()

  # print the currently open tab
  output$opentab <- renderPrint({
    openTab()
  })

  openTab <- callModule(module,"first", reactive({ input$tabsPanel }), openTab)
  openTab <- callModule(module,"second", reactive({ input$tabsPanel }), openTab)

  observeEvent(openTab(), {
    updateTabItems(session, "tabsPanel", openTab())
  })
}

shinyApp(ui = ui, server = server)

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