如何在 R Shiny 中的“navbarPage”菜单项之间同步“selectizeInput”？

Question

让我们看看下面的 R Shiny 仪表板代码，在主菜单中有 'navbarPage' 布局和 2 个项目“第一页”和“第二页”。每个页面都有具有相同元素（1、2、3）的选择器“Selector”。如何同步两个“selectizeInput”元素以显示相同的值存在问题。

例如，如果在“第一页”上选择“2” - 当用户转到“第二页”时，“第二页”上的选择器应该具有“2”值，反之亦然。我想可以使用 R 会话的某种全局变量。很高兴知道您的想法和代码如何有效地实施。

library(shiny)

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

  # 1. Selector for 'Page one'
  output$uo_page_one_selector <- renderUI({

    # 1. Values
    list_values <- c(1:3)
    names(list_values) <- c("One", "Two", "Three")

    # 2. Index of selected element
    index_selected <- 1

    # 3. Result
    selectizeInput('si_page_one_selector', "Selector",
               choices = list_values, multiple = FALSE, 
               selected = list_values[index_selected])
  })

  # 2. Selector for 'Page two'
  output$uo_page_two_selector <- renderUI({

    # 1. Values
    list_values <- c(1:3)
    names(list_values) <- c("One", "Two", "Three")

    # 2. Index of selected element
    index_selected <- 1

    # 3. Result
    selectizeInput('si_page_two_selector', "Selector",
               choices = list_values, 
               multiple = FALSE, 
               selected = list_values[index_selected])
  })

}

ui <- fluidPage(

  navbarPage("Demo",

    tabPanel("One",
         fluidPage(
           fluidRow(uiOutput("uo_page_one_selector")),
           fluidRow("Page one"))),

    tabPanel("Two",
         fluidPage(
           fluidRow(uiOutput("uo_page_two_selector")),
           fluidRow("Page two")))

  )
)

# Run the application 
shinyApp(ui, server)

先谢谢了！

Answer 1

我们可以创建一个全局reactiveVal，然后在用户点击si_page_one_selector 或si_page_two_selector 时更新它

library(shiny)

server <- function(input, output, session) {
list_values <- c(1:3)
names(list_values) <- c("One", "Two", "Three")
rv = reactiveVal(1)
observeEvent(input$si_page_one_selector,{
tmp = rv() # Read reactiveVal
tmp = input$si_page_one_selector
rv(tmp) # set reactiveVal to new value
})

observeEvent(input$si_page_two_selector,{
tmp = rv()
tmp = input$si_page_two_selector
rv(tmp)
})
# 1. Selector for 'Page one'
output$uo_page_one_selector <- renderUI({
# 3. Result
selectizeInput('si_page_one_selector', "Selector",
               choices = list_values, multiple = FALSE, 
               selected = list_values[as.numeric(rv())])
})

# 2. Selector for 'Page two'
output$uo_page_two_selector <- renderUI({
# 3. Result
selectizeInput('si_page_two_selector', "Selector",
               choices = list_values, 
               multiple = FALSE, 
               selected = list_values[as.numeric(rv())])
})

}

ui <- fluidPage(
navbarPage("Demo",
         tabPanel("One",
                  fluidPage(
                    fluidRow(uiOutput("uo_page_one_selector")),
                    fluidRow("Page one"))),

         tabPanel("Two",
                  fluidPage(
                    fluidRow(uiOutput("uo_page_two_selector")),
                    fluidRow("Page two")))
)
)

# Run the application 
shinyApp(ui, server)

PS：此解决方案基于@Florian 的回答here