R Shiny如何将侧边栏矩阵输入控件迁移至模态对话框

现有Shiny应用的运行逻辑如下：

• 「Liabilities Module」标签页侧边面板的矩阵支持数值输入，当前功能正常
• 主面板的输出与标记为「A」的矩阵第一行值绑定

需要实现的调整：

• 将矩阵输入网格从侧边面板移除，仅在点击「Input Liabilities」按钮弹出的模态对话框中展示
• 原有主面板输出与矩阵的绑定关系保持不变，矩阵修改后输出同步更新

仅需要对原代码做2处调整即可实现需求：

1. 删除renderUI({...})中侧边面板渲染逻辑里的matrix1Input("base_input")语句，侧边栏不再展示输入矩阵
2. 在observeEvent(input$showLiabilityGrid,...)的模态对话框定义中补充矩阵输入组件，保持组件ID仍为base_input，原有和矩阵绑定的输出逻辑无需任何修改即可正常运行

library(shiny)
library(shinyMatrix)
library(shinyjs)

button2 <- function(x,y){actionButton(x,y,style="width:90px;margin-bottom:5px;font-size:80%")}

matrix1Input <- function(x){
  matrixInput(x, 
              value = matrix(c(0.2), 4, 1, dimnames = list(c("A","B","C","D"),NULL)),
              rows = list(extend = FALSE,  names = TRUE),
              cols = list(extend = FALSE, names = FALSE, editableNames = FALSE),
              class = "numeric")}

pct <- function(x){paste(format(round(x*100,digits=1),nsmall=1),"%",sep="")} # convert to percentage

vectorBase <- function(x,y){
  a <- rep(y,x)
  b <- seq(1:x)
  c <- data.frame(x = b, y = a)
  return(c)}

vectorPlot <- function(w,x,y,z){plot(w,main=x,xlab=y,ylab=z,type="b",col="blue",pch=19,cex=1.25)}

ui <- 
  pageWithSidebar(
    headerPanel("Model..."),
    sidebarPanel(
      fluidRow(helpText(h5(strong("Base Input Panel")),align="center",
                        style="margin-top:-15px;margin-bottom:5px")),
    # Panels rendered with uiOuput & renderUI in server to stop flashing at invocation
      uiOutput("Panels") 
    ), # close sidebar panel
    mainPanel(
      tabsetPanel(
        tabPanel("By balances", value=2),
        tabPanel("By accounts", value=3), 
        tabPanel("Liabilities module", value=4,
                 fluidRow(h5(strong(helpText("Select model output to view:")))),
                 fluidRow(
                   button2('showVectorValueBtn','Vector values'),
                   button2('showVectorPlotBtn','Vector plots'),
                 ), # close fluid row
                 
                 div(style = "margin-top: 5px"),
                 
                 # Shows outputs on each page of main panel   
                 uiOutput('showResults')), 
        id = "tabselected"
      ) # close tabset panel
    ) # close main panel
  ) # close page with sidebar

server <- function(input,output,session)({
  
  base_input  <- reactive(input$base_input)
  showResults <- reactiveValues()

  yield   <- function(){vectorBase(60,input$base_input[1,1])} # Must remain in server section
  
  # --- Conditional panels rendered here rather than in UI to eliminate invocation flashing ------------>
  output$Panels <- renderUI({
    tagList( 
      conditionalPanel(
        condition="input.tabselected==4",
        actionButton('showLiabilityGrid','Input Liabilities',style='width:100%;background-color:LightGrey'),
        setShadow(id='showLiabilityGrid'),
        div(style = "margin-bottom: 10px"),
        useShinyjs(),
      ), # close conditional panel
      conditionalPanel(condition="input.tabselected==3"),
      conditionalPanel(condition="input.tabselected==4")
    ) # close tagList
  }) # close renderUI
  
  # --- Below produces vector values as default view when first invoking App --------------------------->
  vectorsAll <- reactive({cbind(Period = 1:60,Yld_Rate = pct(yield()[,2]))}) # Produces vector values
  output$table1 <- renderTable({vectorsAll()})
  
  # --- Below produces vector values after clicking "Vector Values" button; see above for pre-click ---->
  observeEvent(input$showVectorValueBtn,
               {showResults$showme <-
                 tagList(tableOutput("table1"))
               },ignoreNULL = FALSE)

  # --- Below produces vector plots -------------------------------------------------------------------->   
  output$graph1 <-renderPlot(vectorPlot(yield(),"A Variable","Period","Rate"))
  observeEvent(input$showVectorPlotBtn,{showResults$showme <- plotOutput("graph1")})
  
  # --- Below sends both vector plots and vector values to UI section above ---------------------------->
  output$showResults <- renderUI({showResults$showme})

  # --- Below for modal dialog inputs ------------------------------------------------------------------>
  
  observeEvent(input$showLiabilityGrid,
               {showModal(modalDialog(
                 matrix1Input("base_input"),
                 footer = modalButton("确认保存")
               ) # close modalDialog
               ) # close showModal
               } # close showModal function
  ) # close observeEvent
  
}) # close server

shinyApp(ui, server)

内容的提问来源于stack exchange，提问作者Curious Jorge - user9788072