Shiny - 根据另一个选项卡中的输入更新一个选项卡中的用户选项

Question

我正在构建一个包含多个标签的应用。我想让用户在一个选项卡中选择一个选项，然后允许他们从同一选项卡中的下游选项中进行子选择。作为下一步，我希望子选择的选项显示为第二个选项卡中的输入选项，允许用户再次进行子选择（独立于第一个选项卡）。

在下面的示例中，选择 y 会导致在第一个选项卡中选择 z 时更新。我希望用户能够子选择一些 z 值（然后绘制）。我希望 z 值的子选择然后显示为第二个选项卡中的唯一选择，并让用户在第二个选项卡中进一步子选择。

到目前为止，我所拥有的是下面的代码。我的问题是：

1. z 在第一个选项卡中的子选择显然不起作用 - updateCheckboxGroupInput 要么取消选择所有内容（如果我没有在函数中指定 select = ，否则它不会让我如果我指定了select = choices，请关闭一些z 值。
2. 第二个选项卡中的更新和子选择似乎完全按照我的意愿工作，我不明白为什么选项卡之间的行为不同。

任何帮助将不胜感激......

library(shiny)
library(dplyr)
library(ggplot2)

df <- data.frame(x = 1:10, y = letters[1:2], z = letters[1:10])
                                                
ui <- navbarPage("App", id = "nav", 
        tabPanel("Tab1", 
            selectInput("SelectY", label = "select value of y", choices = letters[1:2]),
            checkboxGroupInput("SelectZ", label = "select value of z", choices = "a", selected = "a"),
            plotOutput("plot1")),
        tabPanel("Tab2", 
            checkboxGroupInput("SelectZ2", label = "select a subset of z values selected in tab1", 
                choices = "a", selected = "a"),
            plotOutput("plot2")))
        
server = function(input, output, session){
    # function to update the SelectZ (in tab1) based on selection of "y", 
    # and update the SelectZ (in tab2) based on selection of "z" in tab1
    observe({
        y <- input$SelectY
        choices <- df[df$y %in% y,]$z
        updateCheckboxGroupInput(session, "SelectZ", choices = choices, select = choices)
        choices1 <- input$SelectZ
        updateCheckboxGroupInput(session, "SelectZ2", choices = choices1, select = choices1)
        }) 

    output$plot1 <- renderPlot({
        df %>% 
        filter(y == input$SelectY, z %in% input$SelectZ) %>%
        ggplot() +
        geom_point(aes(x = x, y = z))
                                })
                                
    output$plot2 <- renderPlot({
        df %>% 
        filter(y == input$SelectY, z %in% input$SelectZ2) %>%
        ggplot() +
        geom_point(aes(x = x, y = z))
                                })}

shinyApp(ui = ui, server = server)

Answer 1

通过将observe 部分拆分为两个observeEvents，choices 对象不会覆盖您未选中的框。

library(shiny)
library(dplyr)
library(ggplot2)

df <- data.frame(x = 1:10, y = letters[1:2], z = letters[1:10])

ui <- navbarPage("App", id = "nav", 
                 tabPanel("Tab1", 
                          selectInput("SelectY", label = "select value of y", choices = letters[1:2]),
                          checkboxGroupInput("SelectZ", label = "select value of z", choices = "a", selected = "a"),
                          plotOutput("plot1")),
                 tabPanel("Tab2", 
                          checkboxGroupInput("SelectZ2", label = "select a subset of z values selected in tab1", 
                                             choices = "a", selected = "a"),
                          plotOutput("plot2")))

server = function(input, output, session){
  # function to update the SelectZ (in tab1) based on selection of "y", 
  # and update the SelectZ (in tab2) based on selection of "z" in tab1
  observeEvent(input$SelectY, {
    choices <- df[df$y %in% input$SelectY,]$z
    updateCheckboxGroupInput(session, "SelectZ", choices = choices, select = choices)
  }) 
  
  observeEvent(input$SelectZ, {
    choices1 <- input$SelectZ
    updateCheckboxGroupInput(session, "SelectZ2", choices = choices1, select = choices1)
  })
  
  output$plot1 <- renderPlot({
    df %>% 
      filter(y == input$SelectY, z %in% input$SelectZ) %>%
      ggplot() +
      geom_point(aes(x = x, y = z))
  })
  
  output$plot2 <- renderPlot({
    df %>% 
      filter(y == input$SelectY, z %in% input$SelectZ2) %>%
      ggplot() +
      geom_point(aes(x = x, y = z))
  })}

shinyApp(ui = ui, server = server)