Question

我想在R闪亮中创建一个矢量，添加元素并在ui.R中显示结果。

但似乎在server.R中，它会覆盖向量中的旧元素，而是附加向量。

这是我的代码

ui.R

shinyUI(pageWithSidebar(
  headerPanel("actionButton test"),
  sidebarPanel(
    textInput("symb", "Symbol", "SPY"),
    br(),
    actionButton("addButton", "Add"),
    p("Click the button to update the value displayed in the main panel.")
  ),
  mainPanel(
    verbatimTextOutput("nText")
  )
))

server.R

equity_list = c("ACN")
shinyServer(function(input, output) {
  output$nText <- renderText({
    # Take a dependency on input$goButton
    input$goButton

    # Use isolate() to avoid dependency on input$n
    isolate(input$symb)

    equit_list <<- append(equity_list, input$symb)
  })  
})

Answer 1

您好，您的应用中存在两个问题：

您未在actionButton

server.R

添加新元素时必须覆盖equity_list

试试这个：

library(shiny)
runApp(list(
  ui = pageWithSidebar(
    headerPanel("actionButton test"),
    sidebarPanel(
      textInput("symb", "Symbol", "SPY"),
      br(),
      actionButton("addButton", "Add"),
      p("Click the button to update the value displayed in the main panel.")
    ),
    mainPanel(
      verbatimTextOutput("nText")
    )
  ),
  server = function(input, output) {
    equity_list = c("ACN")
    output$nText <- renderText({
      input$addButton
      isolate({
        equity_list <<- append(equity_list, input$symb)
      })
    })  
  }
))

编辑：2个按钮并不容易。你可以尝试下面的应用程序，hic是你必须在“删除”后clic“添加”。我已为textInput更改selectizeInput，它更灵活：

library(shiny)
runApp(list(
  ui = pageWithSidebar(
    headerPanel("actionButton test"),
    sidebarPanel(
      selectizeInput(inputId = "symb", label = "Symbol", selected = "SPY", choices = "SPY", multiple = TRUE, options = list(create = TRUE)),
      br(),
      actionButton("addButton", "Add"),
      p("Click the button to update the value displayed in the main panel."),
      actionButton("deleteButton", "Delete")
    ),
    mainPanel(
      verbatimTextOutput("nText")
    )
  ),
  server = function(input, output, session) {
    equity_list = c("ACN")

    equity_rea <- reactive({
      equity_list <- append(equity_list, input$symb)
    })

observe({
  input$deleteButton
  updateSelectizeInput(session = session, inputId = "symb", selected = "SPY")
})

output$nText <- renderText({
  # with add button
  input$addButton | input$deleteButton
  isolate(equity_rea())
  # without add button
  #equity_rea()
})

} ））

如何在R闪亮的交互式编辑矢量

1 个答案: