更新多个相关输入

Question

我有许多相关的输入字段，并希望在用户点击按钮时更新所有这些字段。用例是加载存储的输入设置。以下是可重复的示例。 “petal”selectInput的选择取决于“species”selectInput中的选择。

当我点击按钮时，只有第一个selectInput会更新。

library(shiny)

data(iris)

# ui function
ui <- fluidPage(
  uiOutput("species.out"),
  uiOutput("petal.out"), 
  actionButton("update", label = "Update")
)

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

  output$species.out = renderUI({
    selectInput("species", label = "", choices = sort(unique(iris$Species)))
  })

  output$petal.out = renderUI({

    req(input$species)

    selectInput("petal", label = "", choices = sort(unique(iris[iris$Species == input$species,]$Petal.Width)))
  })

  observeEvent(input$update,
               {
                 updateSelectInput(session, inputId = "species", selected = "virginica")
                 updateSelectInput(session, inputId = "petal", choices=sort(unique(iris[iris$Species == input$species,]$Petal.Width)), selected = "2.3")
               })

}

shinyApp(ui = ui, server = server)

有没有办法一次更新两个字段？

Answer 1

执行此操作的一种方法是为observeEvent添加另一个input$species，以便更新selectInput花瓣。以下是带有更改的修改后的代码：

library(shiny)

data(iris)

# ui function
ui <- fluidPage(
  uiOutput("species.out"),
  uiOutput("petal.out"), 
  actionButton("update", label = "Update")
)

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

  output$species.out = renderUI({
    selectInput("species", label = "", choices = sort(unique(iris$Species)))
  })

  output$petal.out = renderUI({

    req(input$species)

    selectInput("petal", label = "", choices = sort(unique(iris[iris$Species == input$species,]$Petal.Width)))
  })

  observeEvent(input$update,
               {
                 updateSelectInput(session, inputId = "species", selected = "virginica")
                 # updateSelectInput(session, inputId = "petal", choices=sort(unique(iris[iris$Species == input$species,]$Petal.Width)), selected = "2.3")
               })


  observeEvent(input$species,{
    req(input$petal)
    updateSelectInput(session, inputId = "petal", choices=sort(unique(iris[iris$Species == input$species,]$Petal.Width)), selected = "2.3")
  } )

}

shinyApp(ui = ui, server = server)

希望它有所帮助！

修改

要更新input$petal，即使input$species不符合，以下代码也会有效：

library(shiny)

data(iris)

# ui function
ui <- fluidPage(
  uiOutput("species.out"),
  uiOutput("petal.out"), 
  actionButton("update", label = "Update")
)

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

  output$species.out = renderUI({
    selectInput("species", label = "", choices = sort(unique(iris$Species)))
  })

  output$petal.out = renderUI({

    req(input$species)

    selectInput("petal", label = "", choices = sort(unique(iris[iris$Species == input$species,]$Petal.Width)))
  })

  observeEvent(input$update,
               {
                 updateSelectInput(session, inputId = "species", selected = "virginica")
                 updateSelectInput(session, inputId = "petal", choices=sort(unique(iris[iris$Species == input$species,]$Petal.Width)), selected = "2.3")
               })


  observeEvent(input$species,{
    if(input$petal == "" || req(input$petal))
    updateSelectInput(session, inputId = "petal", choices=sort(unique(iris[iris$Species == input$species,]$Petal.Width)), selected = "2.3")
  } )

}

shinyApp(ui = ui, server = server)

此处我已将条件req(input$petal)更改为if(input$petal == "" || req(input$petal))，并在updateSelectInput(session, inputId = "petal", choices=sort(unique(iris[iris$Species == input$species,]$Petal.Width)), selected = "2.3")的{​​{1}}中添加了observeEvent。