Shiny Reactive renderUI 和多个依赖/耦合输入

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【中文标题】Shiny Reactive renderUI 和多个依赖/耦合输入【英文标题】:Shiny Reactive renderUI and multiple dependent / coupled inputs 【发布时间】:2018-07-04 13:44:21 【问题描述】:

我有以下示例应用程序,我需要能够切换 multiple_choice_1_source 的输入 OR multiple_choice_2_type 而不会破坏应用程序和隐藏 submit_request_button_uiColnamesInput 当输入改变时。基本上,用户应该能够在单击“提交”按钮后修改输入,并且应用程序应该重置为之前的状态。

我尝试过的:

shinyjs() - 这只是隐藏而不清除输入。这意味着一旦我按下submit_request_button,那么对multiple_choice_2_type 所做的任何更改都会被处理并做出反应。在实际应用程序中,我将提交绑定到非常大的表。我想阻止获取 selected_data() 重新运行并清除和隐藏前两个选项中创建的元素。

reactive - 我试图让观察者监听一些反应性触发器,这些触发器从多个输入中获取依赖关系。我使用user_input_rv 来存储值等,但这失败了,因为观察者被多次触发,所以当我点击提交按钮时,reactive() 中的 if 语句被触发两次,实际上是多次下载每个数据集。它也失败了。

isolate - 我无法完成这项工作。我尝试了多种隔离组合,但没有成功。

library(shiny)
library(tidyverse)


ui <- fluidPage(

   selectizeInput(inputId ='multiple_choice_1_source',
                  choices = c("db1","db2","db3","db4"), # like this because we want the selected to be blank on initialisation
                  label = "1. Select source",
                  multiple = FALSE,
                  size = 10,
                  width = '100%'
   )

   ,uiOutput(outputId="multiple_choice_2_type_ui")
   ,uiOutput(outputId="submit_request_button_ui")
   ,uiOutput(outputId="ColnamesInput")
)


server <- function(input, output)


   user_input_rv =  reactiveValues(

      source_picked             = NULL,
      last_used_source          = NULL,

      type_picked               = NULL,
      series_picked             = NULL,
      last_used_series          = NULL,

      selected_data             = NULL,
      final_selection           = NULL
   )

   observeEvent(input$multiple_choice_1_source, 

      user_input_rv$source_picked <- input$multiple_choice_1_source

      #change data loaded under type picked.
      user_input_rv$type_picked <-
         if (        input$multiple_choice_1_source == "db1") paste0(colnames(mtcars))
          else if ( input$multiple_choice_1_source == "db2") paste0(colnames(diamonds))
          else if ( input$multiple_choice_1_source == "db3") NULL
          else if ( input$multiple_choice_1_source == "db4") NULL
         

      output$multiple_choice_2_type_ui <- renderUI(

         selectizeInput( inputId = 'multiple_choice_2_type',
                         choices = paste(user_input_rv$type_picked),
                         label= "2. Select type",
                         multiple = TRUE,
                         size = 10,
                         width = '100%',
                         options = list( placeholder = 'Type',
                                         maxItems =1
                         )
         )
      )

   ) #first observeEvent for source type and data load.

   observeEvent(input$multiple_choice_2_type,

      output$submit_request_button_ui <- renderUI(

            actionButton(
               inputId = "submit_request_button",
               label = " Get data "
         )
      )
   )#second observeEvent for submit_request_button_ui

   observeEvent(input$submit_request_button, 

      selected_data <- reactive(

         if( input$multiple_choice_1_source =="db1")

             mtcars


          else if ( input$multiple_choice_1_source == "db1")                 

         diamonds


          else if ( input$multiple_choice_1_source == "db3")       NULL

          else if ( input$multiple_choice_1_source == "db4") NULL
         



      )

      user_input_rv$series_picked <- input$multiple_choice_2_type

      user_input_rv$selected_data <- selected_data()


            min_cols <- as.integer(1) # default 1
            max_cols <- as.integer(length(colnames(selected_data())))
            #print(max_cols)


            #this renderUI creates the right-hand side column of the app COLUMNS
            output$ColnamesInput <-  renderUI(

               lapply(min_cols:max_cols, function(z) 

                  column(width = 3,
                         offset = 0,
                            selectInput( inputId = paste0("cols","_",z),
                                         label = paste(input$multiple_choice_2_type,": ",colnames(selected_data())[z]),
                                         choices = unique(selected_data()[[z]]),
                                         multiple = TRUE
                            ) #selectizeInput

                  )

               )#lapply inner

            ) #renderUI for columns

   ) #third observeEvent for data selection and customisation



shinyApp(ui = ui, server = server)

【问题讨论】:

您是否尝试过使用eventReactive 是的,但我只尝试将反应式替换为selected_data() 如果您希望仅在按下提交按钮时更改值,那么您为什么使用reactive expressionreactiveValues 好问题 - 总结了我对闪亮反应的舒适程度...... 【参考方案1】:

这是我从中删除 reactive expression 并改用局部变量 selected_data 的代码。

  observeEvent(input$submit_request_button, 

    # selected_data <- reactive(

      # browser()
    selected_data <- NULL

      if( input$multiple_choice_1_source =="db1")

        selected_data <- mtcars


       else if ( input$multiple_choice_1_source == "db1")                 

        selected_data <- diamonds


       else if ( input$multiple_choice_1_source == "db3")       selected_data <- NULL

       else if ( input$multiple_choice_1_source == "db4")selected_data <-   NULL
      



    # )

    user_input_rv$series_picked <- isolate(input$multiple_choice_2_type)

    user_input_rv$selected_data <- selected_data


    min_cols <- as.integer(1) # default 1
    max_cols <- as.integer(length(colnames(selected_data)))
    #print(max_cols)


    #this renderUI creates the right-hand side column of the app COLUMNS
    output$ColnamesInput <-  renderUI(

      lapply(min_cols:max_cols, function(z) 

        column(width = 3,
               offset = 0,
               selectInput( inputId = paste0("cols","_",z),
                            label = paste(isolate(input$multiple_choice_2_type),": ",colnames(selected_data)[z]),
                            choices = unique(selected_data[[z]]),
                            multiple = TRUE
               ) #selectizeInput

        )

      )#lapply inner

    ) #renderUI for columns

  ) #third observeEvent for data selection and customisation

现在,当您更改选择输入选项时,ColnamesInput 不会被触发。只有在您单击提交按钮后才会触发它。

[编辑]:

可能不是最好的方法,但我认为我能够实现您想要的。另外,我冒昧地使用了您的服务器中已经定义的reactiveValue。看看下面修改后的服务器代码:

server <- function(input, output)

  user_input_rv =  reactiveValues(

    source_picked             = NULL,
    last_used_source          = NULL,

    type_picked               = NULL,
    series_picked             = NULL,
    last_used_series          = NULL,

    selected_data             = NULL,
    final_selection           = NULL
  )



  observeEvent(input$multiple_choice_1_source, 


    user_input_rv$source_picked <- input$multiple_choice_1_source

    ###Start: To check if the source changed#########
    if(!is.null(user_input_rv$last_used_source))
    
      if(user_input_rv$last_used_source != user_input_rv$source_picked)
      
        shinyjs::hide("ColnamesInput")
        user_input_rv$last_used_source = user_input_rv$source_picked
      
    else
    
      user_input_rv$last_used_source = user_input_rv$source_picked
    
    ###End: To check if the source changed#########


    #change data loaded under type picked.
    user_input_rv$type_picked <-
      if (        input$multiple_choice_1_source == "db1") paste0(colnames(mtcars))
       else if ( input$multiple_choice_1_source == "db2") paste0(colnames(diamonds))
       else if ( input$multiple_choice_1_source == "db3") NULL
       else if ( input$multiple_choice_1_source == "db4") NULL
      

    output$multiple_choice_2_type_ui <- renderUI(

      selectizeInput( inputId = 'multiple_choice_2_type',
                      choices = paste(user_input_rv$type_picked),
                      label= "2. Select type",
                      multiple = TRUE,
                      size = 10,
                      width = '100%',
                      options = list( placeholder = 'Type',
                                      maxItems =1
                      )
      )
    )

  ) #first observeEvent for source type and data load.

  observeEvent(input$multiple_choice_2_type,


    ###Start: To check if the series changed######### 
    user_input_rv$series_picked <- input$multiple_choice_2_type

    if(!is.null(user_input_rv$last_used_series))
    
      if(user_input_rv$last_used_series != user_input_rv$series_picked)
      
        shinyjs::hide("ColnamesInput")
        user_input_rv$last_used_series = user_input_rv$series_picked
      
    else
    
      user_input_rv$last_used_series = user_input_rv$series_picked
    
    ###End: To check if the series changed#########

    output$submit_request_button_ui <- renderUI(

      actionButton(
        inputId = "submit_request_button",
        label = " Get data "
      )
    )
  )#second observeEvent for submit_request_button_ui

  observeEvent(input$submit_request_button, 

    # selected_data <- reactive(

      # browser()
    shinyjs::show("ColnamesInput")
    selected_data <- NULL

      if( input$multiple_choice_1_source =="db1")

        selected_data <- mtcars


       else if ( input$multiple_choice_1_source == "db1")                 

        selected_data <- diamonds


       else if ( input$multiple_choice_1_source == "db3")       selected_data <- NULL

       else if ( input$multiple_choice_1_source == "db4")selected_data <-   NULL
      



    # )

    user_input_rv$series_picked <- isolate(input$multiple_choice_2_type)

    user_input_rv$selected_data <- selected_data


    min_cols <- as.integer(1) # default 1
    max_cols <- as.integer(length(colnames(selected_data)))
    #print(max_cols)


    #this renderUI creates the right-hand side column of the app COLUMNS
    output$ColnamesInput <-  renderUI(

      lapply(min_cols:max_cols, function(z) 

        column(width = 3,
               offset = 0,
               selectInput( inputId = paste0("cols","_",z),
                            label = paste(isolate(input$multiple_choice_2_type),": ",colnames(selected_data)[z]),
                            choices = unique(selected_data[[z]]),
                            multiple = TRUE
               ) #selectizeInput

        )

      )#lapply inner

    ) #renderUI for columns

  ) #third observeEvent for data selection and customisation


希望对你有帮助!

【讨论】:

谢谢@SBista。问题是当两个selectizes 的选择发生变化时,ColnamesInput 仍然可见。我需要隐藏它们。 @J.Doe.,我已经编辑了代码来实现你想要的。看一看。希望对您有所帮助! 谢谢@SBista。它完成了工作。我认为它尽可能高效。我在顶部的reactiveValues 上走在正确的轨道上,但我不止一次失败了。 100% 正确的是嵌套的 if 语句。再次感谢您!

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