r - Shiny 的动态 selectizeInput

Question

我试图允许用户在 selectizeInput 中键入值，以从长列表中查找他们正在搜索的内容(从而避免滚动操作)。当用户删除默认值“None”(在本例中)时，他们会被踢出输入框，必须返回并输入他们要查找的内容。有没有办法避免这种情况，以便用户可以退格“无”来删除它并搜索值，而不会被推出盒子？

library(shiny)
library(shinydashboard)


ui <- dashboardPage(
dashboardHeader(title = "Dynamic selectInput"),
dashboardSidebar(
sidebarMenu(
  menuItemOutput("menuitem")
)
),
dashboardBody(
selectizeInput("heir1","Heirarchy1",c("NONE",letters),selected="NONE"),
selectizeInput("heir2","Heirarchy2",c("NONE",letters),selected="NONE"),
selectizeInput("heir3","Heirarchy3",c("NONE",letters),selected="NONE")
 )
 )

server <- function(input, output, session) {
output$menuitem <- renderMenu({
menuItem("Menu item", icon = icon("calendar"))
})

heirarchy<-c(letters)

observe({
hei1<-input$heir1
hei2<-input$heir2
hei3<-input$heir3

choice1<-c("NONE",setdiff(heirarchy,c(hei2,hei3)))
choice2<-c("NONE",setdiff(heirarchy,c(hei1,hei3)))
choice3<-c("NONE",setdiff(heirarchy,c(hei1,hei2)))

updateSelectizeInput(session,"heir1",choices=choice1,selected=hei1)
updateSelectizeInput(session,"heir2",choices=choice2,selected=hei2)
updateSelectizeInput(session,"heir3",choices=choice3,selected=hei3)

 })

 }

 shinyApp(ui, server)

Answer 1

您可以使用 Selectize JS 中的任何一个通过 selectizeInput() 的 options 参数来添加插件。

请注意，仅更新第一个输入。

这是代码:

library(shiny)
library(shinydashboard)


ui <- dashboardPage(
    dashboardHeader(title = "Dynamic selectInput"),
    dashboardSidebar(
        sidebarMenu(
            menuItemOutput("menuitem")
        )
    ),
    dashboardBody(

        selectizeInput("heir1","Heirarchy1",c("NONE",letters),selected="NONE",
                       # use this syntax to bring in selectize.js plugins :)
                       options = list(plugins = list('restore_on_backspace'))),

        selectizeInput("heir2","Heirarchy2",c("NONE",letters),selected="NONE"),
        selectizeInput("heir3","Heirarchy3",c("NONE",letters),selected="NONE")
    )
)

server <- function(input, output, session) {
    output$menuitem <- renderMenu({
        menuItem("Menu item", icon = icon("calendar"))
    })

    heirarchy<-c(letters)

    observe({

        hei1<-isolate(input$heir1) # don't allow re-evaluation as users type

        hei2<-input$heir2
        hei3<-input$heir3

        choice1<-c("NONE",setdiff(heirarchy,c(hei2,hei3)))
        choice2<-c("NONE",setdiff(heirarchy,c(hei1,hei3)))
        choice3<-c("NONE",setdiff(heirarchy,c(hei1,hei2)))

        updateSelectizeInput(session,"heir1",choices=choice1,selected=hei1)
        updateSelectizeInput(session,"heir2",choices=choice2,selected=hei2)
        updateSelectizeInput(session,"heir3",choices=choice3,selected=hei3)

    })

}

shinyApp(ui, server)

请注意，isolate() 对于防止 updateSelectizeeInput() 被重新调用并在用户键入时弄乱所有内容是必要的。

编辑:

抱歉，伙计，当我回答时，误读了您想要的行为。我想如果你删除 options =，但保留 isolate()，你会得到你想要的。

selectizeInput("heir1","Heirarchy1",c("NONE",letters),selected="NONE")

正是没有 isolate() 的 updateSelectizeInput() 导致光标离开输入字段并要求用户在删除后重新单击。

如果这不是您所描述的内容，请告诉我。干杯!