使用removeUI /包装多个元素，使用标签$ div（）为每个变量分配一个ID来删除多个元素 [英] Removing multiple elements with removeUI / wrapping multiple elements with tags$div() assigning an id for each variable

问题描述

我建议使用 insertUI 这里，发现这是一个很好的功能。以下代码允许使用 insertUI 为单个或多个元素生成控件窗口小部件，但会引入 removeUI 相关部件。尝试 jQuery 选项来删除插入的UI元素，但没有解决。我从闪亮动态UI 中找到了以下内容，即请注意， ，如果您在一个调用中插入多个元素，则必须将它们包装在tagList（）或tags $ div（）中（后一个选项的优点是您可以给它一个id以便于引用或删除稍后）。此外，评论这里给了一些线索，即标签$ div（id =sepal.width.div，sliderInput（sepal.width.slider，...）），但我缺乏 HTML / CSS 我在看（a）用标签$ div（）包装多个widget元素为每个变量分配一个唯一的id，将用于 removeUI ; （b）通过 removeUI 调用多个元素。

I was suggested using insertUI here and found that it is a great feature. The following code allows to generate control widgets for a single or multiple elements using insertUI, but struck on incorporating removeUI related part. Tried jQuery options to remove inserted UI elements but did not work out. I found the following from Shiny dynamic UI, i.e., Note that, if you are inserting multiple elements in one call, you must wrap them in either a tagList() or a tags$div() (the latter option has the advantage that you can give it an id to make it easier to reference or remove it later on). Also, comments here gave some clues, i.e., tags$div(id="sepal.width.div", sliderInput("sepal.width.slider", ...)), but my lack of HTML/CSS knowledge stops me going forward. I'm looking at (a) wrapping multiple widget element(s) with tags$div() assigning a unique id for each variable, which will be used in removeUI; (b) calling multiple elements via removeUI.

varnames <- names(iris[,1:4]) # names
varinit <- apply(iris[,1:4],2,median) # initival value used in slider
varmin <- apply(iris[,1:4],2,min) # min.
varmax <- apply(iris[,1:4],2,max) # max. 

ListofSelVars <<- vector(mode="character")

# control widgets for all elements
allControls <- lapply(setNames(varnames, varnames), function(x) {

   sliderInput(x, x, varmin[x], varmax[x], c(varmin[x], varinit[x]), 
               round = -2)   
})

ui <- navbarPage(
   tabPanel("Plot",
            sidebarLayout(
               sidebarPanel(
                  checkboxGroupInput("ConditioningVariables", "Conditioning variables (choose one or more):",
                                     varnames,inline = TRUE),
                  # add an action button
                  actionButton("add", "Update UI elements")
               ),
               mainPanel()
            )
   )
)

server <- function(input, output, session) {
   observeEvent(input$add, {
      insertUI(
         selector ='#add',
         where = "afterEnd",
         ui = allControls[setdiff(input$ConditioningVariables,ListofSelVars)]
      )

      ## removeUI related goes, here
      ## removeUI(selector=paste0())
      ## setdiff(ListofSelVars,input$ConditioningVariables) gives elements to be removed

      ## Global variable, keep track of elements that are selected

      ListofSelVars <<- input$ConditioningVariables

   })

}
shinyApp(ui, server)

推荐答案

这里是工作代码。主要问题是这里的名称，即 Sepal.Width 。我把每个滑块用一个div像 div.Sepal.Width ，以便它更容易删除。 removeUI 需要一个jQuery选择器，所以看起来像＃div.Sepal.Width 会工作，除了它因为。本身是一个jQuery选择器，意味着 class ，所以我们需要双重转义。。当然你也可以删除。当你第一次创建divs，从而避免麻烦...

Here is the working code. The main issue is with the names here, i.e. Sepal.Width. I wrapped each slider with a div with id like div.Sepal.Width so that it is easier to remove. removeUI requires a jQuery selector, so it appears that something like #div.Sepal.Width would work, except that it does not, because . is itself a jQuery selector that means class, so we need to double escape the .. Of course you can also remove the . when you first create the divs, thus avoiding the trouble...

varnames <- names(iris[,1:4]) # names
varinit <- apply(iris[,1:4],2,median) # initival value used in slider
varmin <- apply(iris[,1:4],2,min) # min.
varmax <- apply(iris[,1:4],2,max) # max. 

ListofSelVars <<- vector(mode="character")

# control widgets for all elements
allControls <- lapply(setNames(varnames, varnames), function(x) {
  tags$div(id=paste0("div.",x), sliderInput(x, x, varmin[x], varmax[x], c(varmin[x], varinit[x]), 
              round = -2))
})

ui <- fluidPage(

  titlePanel("Dynamic sliders"),

  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput("ConditioningVariables", "Conditioning variables (choose one or more):",
                         varnames,inline = TRUE),
      # add an action button
      actionButton("add", "Update UI elements")
    ),

    mainPanel(
      uiOutput("plot_out")
    )
  )
)

server <- function(input, output, session) {
  observeEvent(input$add, {

    insertUI(
      selector ='#add',
      where = "afterEnd",
      ui = allControls[setdiff(input$ConditioningVariables,ListofSelVars)]
    )

    ListofRemoval <- setdiff(ListofSelVars,input$ConditioningVariables)

    for (item in ListofRemoval) {
      item = gsub(".", "\\.", item, fixed=TRUE)
      item = paste0("#div\\.", item)
      removeUI(item)
    }

    ListofSelVars <<- input$ConditioningVariables

  })

}
shinyApp(ui, server)

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