2

我试图想出一种方法来防止选择输入在其依赖的数据发生更改时重置。理想情况下，随着更多数据的到达，选择会悄悄地扩展，不会造成视觉中断或输入值重置。我试过使用updateSelectInput，但没有成功。我创建了一个合理地近似我的问题的示例，留下了我的评论和想法，以显示我试图提出解决方案的地方，并希望其他人有更好的想法可以分享。与往常一样，提前感谢您。-先天

library(shiny)

if (interactive()) {

ui <- fluidPage(

  titlePanel("Is It Possible To Prevent The Select Input From Resetting with New Data Arriving?"),


  sidebarLayout(
      sidebarPanel(
      shiny::uiOutput(outputId = "streaming_select")
    ),

    mainPanel(
    tableOutput("table")
    )
  )
)

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

  session_launched<- reactiveValues(count=1)
  fake_global_rv_list<- reactiveValues()
  fake_global_rv_list$tmp<- data.frame(glob_0001=runif(10))
  session_rv_list<- reactiveValues()
  session_rv_list$tmp<- data.frame(sess_0001=runif(10)) 

  # Simulating Streaming Data every 7 seconds
  shiny::observe({
    shiny::invalidateLater(millis = 7000)
    shiny::isolate({
      shiny::showNotification(ui = "Generating Random Data", type = "default", duration = 3)
      tmp<- data.frame(runif(10) )
      colnames(tmp)<- paste0("stream_",format(as.numeric(Sys.time())))
      session_rv_list$tmp<- cbind(session_rv_list$tmp,  tmp) # Put the random data into the reactive Values list
    }) 

  })

  full_dat<- shiny::reactive({ cbind(fake_global_rv_list$tmp,  session_rv_list$tmp) })


  # Table of 'Streaming' Data 
  output$table <- renderTable({
    full_dat()
  })

  ## Select Input that let's you pick a single column
  output$streaming_select<- shiny::renderUI({
    if(!is.null(full_dat())){
      if(session_launched$count==1){
        out<- shiny::selectizeInput(inputId = "streaming_select_input", label="Pick A Column", choices = unique(colnames(full_dat())), selected = NULL, multiple = TRUE)
      } 
    }
  })
  ## Possible Ideas (?) BELOW

  # select_choices<- shiny::eventReactive(full_dat(), {
  #   if(!is.null(full_dat())){
  #     if(session_launched$count==1){
  #       out<- list( choices = unique(colnames(full_dat())), selected = NULL)
  #       #shiny::selectizeInput(inputId = "streaming_select_input", label="Pick A Column", choices = unique(colnames(full_dat())), selected = NULL, multiple = TRUE)
  #       session_launched$count<- 2
  #       return(out)
  #     } else if(session_launched$count > 1){
  #       old_selections<- input$streaming_select_input
  #       out<- list( choices = unique(colnames(full_dat())), selected = old_selections)
  #       return(out)
  #       #shiny::updateSelectizeInput(session, inputId = "streaming_select_input", choices = unique(colnames(full_dat())), selected = old_selections)
  #     }
  #   }
  # })
  # observeEvent(select_choices(), {
  #   cat("STR of select_choices is...", "\n")
  #   cat(str(select_choices()), "\n")
  # })
  # 

  # shiny::observeEvent(full_dat(), {
  #   if(session_launched$count != 1){
  #     old_selections<- input$streaming_select_input
  #     shiny::updateSelectizeInput(session, inputId = "streaming_select_input", choices = unique(colnames(full_dat())), selected = old_selections)
  #   }
  # })


}

shinyApp(ui, server)

}
4

1 回答 1

1

下面是一个有效的例子。我selectizeInput在ui零件中创建 ，并full_dat使用observeEvent. 我必须在此更新步骤中存储并重置选择，以防止将其设置为NULL.

library(shiny)

if (interactive()) {

  ui <- fluidPage(

    titlePanel("Is It Possible To Prevent The Select Input From Resetting with New Data Arriving?"),


    sidebarLayout(
      sidebarPanel(
        shiny::selectizeInput(inputId = "streaming_select_input", label="Pick A Column",
                               choices = NULL,
                               selected = NULL,
                               multiple = TRUE)
      ),

      mainPanel(
        tableOutput("table")
      )
    )
  )

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

    session_launched<- reactiveValues(count=1)
    fake_global_rv_list<- reactiveValues()
    fake_global_rv_list$tmp<- data.frame(glob_0001=runif(10))
    session_rv_list<- reactiveValues()
    session_rv_list$tmp<- data.frame(sess_0001=runif(10)) 

    # Simulating Streaming Data every 7 seconds
    shiny::observe({
      shiny::invalidateLater(millis = 7000)
      shiny::isolate({
        shiny::showNotification(ui = "Generating Random Data", type = "default", duration = 3)
        tmp<- data.frame(runif(10) )
        colnames(tmp)<- paste0("stream_",format(as.numeric(Sys.time())))
        session_rv_list$tmp<- cbind(session_rv_list$tmp,  tmp) # Put the random data into the reactive Values list
      }) 

    })

    full_dat<- shiny::reactive({ cbind(fake_global_rv_list$tmp,  session_rv_list$tmp) })


    # Table of 'Streaming' Data 
    output$table <- renderTable({
      full_dat()
    })

    ## Select Input that let's you pick a single column
    observeEvent(full_dat(), {
      selectedCols <- input$streaming_select_input
      updateSelectizeInput(session, "streaming_select_input", choices = colnames(full_dat()), selected = selectedCols)
    })
  }

  shinyApp(ui, server)

}
于 2020-05-01T08:00:58.467 回答