如何更新通过 renderUI 和 uiOutput 插入的 R shiny 中的 userMessages？

Question

当我通过renderUI和uiOutput将shinydashboard userMessages ， updateUserMessages不会更新消息。

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)

ui <- fluidPage(
    dashboardPage(
        dashboardHeader(),
        dashboardSidebar(),
        dashboardBody(
            fluidRow(
                uiOutput("user_messages"),
                textInput("message_text",label="", value = ""),
                actionButton("message_send", "Send")
            )
        )
    )
)

server <- function(input, output, session) {
    
    output$user_messages <- renderUI({
        userMessages(
            width = 6,
            status = "danger",
            id = "user_messages",
            userMessage(
                author = "David",
                date = "20 Jan 2:00 pm",
                image = "",
                type = "received",
                "Message text"
            )
        )
    })
    
    observeEvent(input$message_send, {
        print("Button clicked")
        shinydashboardPlus::updateUserMessages(
            "user_messages",
            action = "add",
            content = list(
                author = "David",
                date = "Now",
                image = "",
                type = "sent",
                text = input$message_text
            )
        )
    })
}

shinyApp(ui, server)

我想实现一个像这样工作的应用程序：

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)

ui <- fluidPage(
    dashboardPage(
        dashboardHeader(),
        dashboardSidebar(),
        dashboardBody(
            fluidRow(
                userMessages(
                    width = 6,
                    status = "danger",
                    id = "user_messages",
                    userMessage(
                        author = "David",
                        date = "20 Jan 2:00 pm",
                        image = "",
                        type = "received",
                        "Message text"
                    )
                ),
                textInput("message_text",label="", value = ""),
                actionButton("message_send", "Send")
            )
        )
    )
)

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

    observeEvent(input$message_send, {
        print("Button clicked")
        shinydashboardPlus::updateUserMessages(
            "user_messages",
            action = "add",
            content = list(
                author = "David",
                date = "Now",
                image = "",
                type = "sent",
                text = input$message_text
            )
        )
    })
}

shinyApp(ui, server)

Answer 1

正如@ismirsehregal 建议的那样，我使用insertUI ，它的工作方式与我预期的一样：

library(shiny)
library(shinydashboard)
library(shinydashboardPlus)

ui <- fluidPage(
    dashboardPage(
        dashboardHeader(),
        dashboardSidebar(),
        dashboardBody(
            fluidRow(
                id="user_messages_row",
                textInput("message_text",label="", value = ""),
                actionButton("message_send", "Send")
            )
        )
    )
)

server <- function(input, output, session) {
    
    insertUI(
        selector = '#user_messages_row',
        where = 'afterBegin',
            userMessages(
                    width = 6,
                    status = "danger",
                    id = "user_messages",
                    userMessage(
                        author = "David",
                        date = "20 Jan 2:00 pm",
                        image = "",
                        type = "received",
                        "Message text"
                    )
                )
    )
    
    observeEvent(input$message_send, {
        print("Button clicked")
        shinydashboardPlus::updateUserMessages(
            "user_messages",
            action = "add",
            content = list(
                author = "David",
                date = "Now",
                image = "",
                type = "sent",
                text = input$message_text
            )
        )
    })
}

shinyApp(ui, server)