Shiny - 使用 insertUI 的动态数据过滤器

我是闪亮的新手，正在尝试编写一个应用程序，用户可以在其中动态添加数据过滤器（请参阅下面的代码）。 我认为 insertUI 和 remove UI 对于这个目的来说非常酷。 但是，我有几个问题：

    1) I cannot address dynamically generates input$ids (see filterId in the code, l. 36 and l. 58)
    2) in updateCheckboxGroupInput (l. 62) checkboxes are not preselected.
    3) I cannot select data rows using which() (l. 74)
    4) The checkboxes are not displayed inside the column, but spread over the whole page.

我非常感谢任何提示。

谢谢，乔迪

这里是代码：

library(shiny)

rowvalues <- function(col,data) {
  as.list(unique(data[col]))
}

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      fluidRow(
        column(6, actionButton('addFilter', 'Add filter')),
        column(6, actionButton('removeFilter', 'Remove filter')),
        offset = 6
      ),
      tags$hr(),
      tags$div(id = 'placeholderAddRemFilt'),
      tags$div(id = 'placeholderFilter'),
      width = 4 # sidebar
    ),
    mainPanel(
      tableOutput("data")
    )
  )
)

server <- function(input, output,session) {
  filter <- character(0)

  observeEvent(input$addFilter, {
    add <- input$addFilter
    filterId <- paste0('Filter', add)
    headers <- names(mtcars)
    insertUI(
      selector = '#placeholderFilter',
      ui = tags$div(
        # selectInput(filterId, label = paste0("Filter ",add), # does not work
        selectInput("ColFilter", label = paste0("Filter ",add), 
                    choices = as.list(headers), 
                    selected = 1),
        checkboxGroupInput("RowFilter", label = "Select variable values",
                           choices = NULL, selected = NULL, 
                           inline = TRUE, width = 4000),
        id = filterId
      )
    )

    filter <<- c(filter,filterId)
  })

  observeEvent(input$removeFilter, {
    removeUI(
      ## pass in appropriate div id
      selector = paste0('#', filter[length(filter)])
    )
    filter <<- filter[-length(filter)]
  })

  # observeEvent(input$filterId, { # does ntót work
  observeEvent(input$ColFilter, {
    col <- input$ColFilter
    values <- as.list(unique(mtcars[col]))[[1]]
    updateCheckboxGroupInput(session,"RowFilter", label = "Select variable    values", 
                              choices = values, selected = values, 
                              inline = TRUE)
  })

  output$data <- renderTable({
    col <- input$ColFilter
    rows <- input$RowFilter
    print(c("selected col: ",col))
    print(c("selected rows: ",as.vector(rows)))
    if(is.null(col)) mtcars
    else {
      mtcars[which(mtcars$col != rows),]
    }
  })
 }

shinyApp(ui = ui, server = server)

请参阅下面的代码以获取我的建议。我基本上做了您希望/尝试做的事情，即动态添加观察者，以便每个新的过滤器元素都有自己的观察者。事实证明：你可以做到。就这样。因此，我在渲染 ui 元素的确切observeEvent 中添加了观察者，为它们提供所需的反应性。我什至添加了“个人”删除按钮，这比仅删除最底部的按钮更方便。此外，处理所有这些过滤器的逻辑将是一个聚合列表，用于存储当前在各个过滤器中选择的所有信息。这使得 renderTable 部分变得更加容易。

请熟悉代码，如果有任何不确定之处请询问。

此致

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      fluidRow(
        column(6, actionButton('addFilter', 'Add filter')),
        offset = 6
      ),
      tags$hr(),
      tags$div(id = 'placeholderAddRemFilt'),
      tags$div(id = 'placeholderFilter'),
      width = 4 # sidebar
    ),
    mainPanel(
      tableOutput("data")
    )
  )
)

server <- function(input, output,session) {
  filter <- character(0)

  makeReactiveBinding("aggregFilterObserver")
  aggregFilterObserver <- list()

  observeEvent(input$addFilter, {
    add <- input$addFilter
    filterId <- paste0('Filter_', add)
    colfilterId <- paste0('Col_Filter_', add)
    rowfilterId <- paste0('Row_Filter_', add)
    removeFilterId <- paste0('Remove_Filter_', add)
    headers <- names(mtcars)
    insertUI(
      selector = '#placeholderFilter',
      ui = tags$div(id = filterId,
        actionButton(removeFilterId, label = "Remove filter", style = "float: right;"),
        selectInput(colfilterId, label = "Some Filter", choices = as.list(headers), selected = 1),
        checkboxGroupInput(rowfilterId, label = "Select variable values",
                           choices = NULL, selected = NULL, width = 4000)
      )
    )

    observeEvent(input[[colfilterId]], {

      col <- input[[colfilterId]]
      values <- as.list(unique(mtcars[col]))[[1]]

      updateCheckboxGroupInput(session, rowfilterId , label = "Select variable    values", 
                              choices = values, selected = values, inline = TRUE)

      aggregFilterObserver[[filterId]]$col <<- col
      aggregFilterObserver[[filterId]]$rows <<- NULL
    })

    observeEvent(input[[rowfilterId]], {

      rows <- input[[rowfilterId]]

      aggregFilterObserver[[filterId]]$rows <<- rows

    })

    observeEvent(input[[removeFilterId]], {
      removeUI(selector = paste0('#', filterId))

      aggregFilterObserver[[filterId]] <<- NULL

    })
  })

  output$data <- renderTable({

    dataSet <- mtcars

    invisible(lapply(aggregFilterObserver, function(filter){

      dataSet <<- dataSet[which(!(dataSet[[filter$col]] %in% filter$rows)), ]

    }))

    dataSet
  })
 }

shinyApp(ui = ui, server = server)