依赖闪亮的物体

在我的应用程序，用户需要选择一个文件夹，该文件夹中，他需要选择一个文件（文件名后缀为“.seg”）依赖闪亮的物体

此代码工作 -

library(shiny) 
ui <- shinyUI(fluidPage(
    # select a folder 
    column(2, absolutePanel(fixed = TRUE, width = '180px', 
          selectInput("pick_a_folder", label = '', selected='choose a folder', 
             choices = setNames(as.list(c('choose a folder', 
                    basename(list.dirs(recursive = FALSE)))), 
                  c('choose a folder', 
                  basename(list.dirs(recursive = FALSE))))))), 
    # select a file 
    column(2, absolutePanel(fixed = TRUE, width = '180px', 
          conditionalPanel(condition='!(input.pick_a_folder=="choose a folder")', 
              uiOutput('fileselection')))) 
)) 
server <- shinyServer(function(input, output) { 
    # dinamic file selection. find the files list after folder is choosen 
    output$fileselection <- renderUI({ 
    selectInput('pick_file', '', selected = 'choose a file', 
       choices=setNames(as.list(c('choose a file',basename(list.files(path=input$pick_a_folder,recursive=FALSE, pattern='\\.seg$')))), 
           c('choose a file',basename(list.files(path = input$pick_a_folder, recursive = FALSE, pattern='\\.seg$'))))) 
    }) 
}) 

shinyApp(ui = ui, server = server)

问题是，如果我在运行代码后向工作目录添加文件夹，则不会显示该文件夹。于是，我就夹选择移动到服务器，并使其依赖于一个刷新按钮，但我得到一个错误的list.files

错误：无效的“路径”的说法这是我的代码 -

library(shiny) 
ui <- shinyUI(fluidPage(
    # refresh butten for root directory 
    column(1, absolutePanel(fixed=TRUE, actionButton("refresh_wd", "refresh"))), 

    # select a folder 
    column(2, absolutePanel(fixed = TRUE, width = '180px', uiOutput('folderselection'))), 

    # select a file 
    column(2, absolutePanel(fixed = TRUE, width = '180px', 
          conditionalPanel(condition='!(input.pick_a_folder=="choose a folder")', 
              uiOutput('fileselection')))) 
)) 

server <- shinyServer(function(input, output) { 
    # refresh root directory 
    wd_folders <- eventReactive(input$refresh_wd, { 
    basename(list.dirs(recursive = FALSE)) 
    }) 

    output$folderselection <- renderUI({ 
    selectInput('pick_a_folder', '', selected = 'choose a folder', 
       choices = setNames(as.list(c('choose a folder', wd_folders())), 
            c('choose a folder', wd_folders()))) 
    }) 

    # dinamic file selection. find the file list after folder is choosen 
    output$fileselection <- renderUI({ 
    selectInput('pick_a_file', '', selected = 'choose a file', 
       choices=setNames(as.list(c('choose a file',basename(list.files(path=input$pick_a_folder,recursive=FALSE, pattern='\\.seg$')))), 
           c('choose a file',basename(list.files(path = input$pick_a_folder, recursive = FALSE, pattern='\\.seg$'))))) 
    }) 
}) 

shinyApp(ui = ui, server = server)

因为你使用eventReactive()将只显示文件夹，甚至文件夹选择列表中点击某人后o任何帮助将不胜感激

来源

2017-02-20 T.G.

只是为了确保：您是否希望用户在服务器端选择文件，还是从自己的计算机中选择文件？ –

从我的脚本在哪里，在服务器 –

所以'fileInput（）'不是你正在寻找的然后：http://shiny.rstudio.com/reference/shiny/latest/fileInput.html –

'刷新'按钮。您可以通过使用ignoreNULL = FALSE避免这种情况：

wd_folders <- eventReactive(input$refresh_wd, { 
    basename(list.dirs(recursive = FALSE)) 
    }, ignoreNULL = FALSE)

如果你不这样做，的wd_folders()值将是NULL下手，让你对你的conditionalPanel条件满足（这不是“选择文件夹” ），因此您的应用程序尝试读取目录NULL中的文件。这给你你的错误。

如果你想成为额外的安全，你可以添加validate(need())到UI渲染为好，如：

output$fileselection <- renderUI({ 
    validate(need(input$pick_a_folder, label = "Pick a folder first")) 
    validate(need(dir.exists(input$pick_a_folder), 
        label = "Something went wrong. Contact me.")) 
    selectInput('pick_a_file', '', selected = 'choose a file', 
       ...) 
    })

这是没有必要解决您的问题，但我觉得在闪亮的好习惯。

来源

2017-02-20 13:35:00

谢谢！现在工作正常。在我开始使用它之前，我会阅读关于'validate（need（））'的内容。非常感谢！ –

以下是每5秒钟自动刷新一次文件夹的最小示例。由于@JoriMeys解释的原因，它仍然会产生关于path无效的初始警告。

library(shiny) 
ui <- shinyUI(fluidPage(

    column(1, 
      absolutePanel(fixed=TRUE, 

         textOutput('wd'), 

         uiOutput('folderselection'), 
         conditionalPanel(
          condition='!(input.pick_a_folder=="choose a folder")', 
          uiOutput('fileselection')) 
      ) 
    ) 
) 
) 


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

    output$wd <- renderText(basename(
     list.files(path = input$pick_a_folder, 
        recursive=FALSE) 
    ) 
    ) 
    button <- reactiveTimer(intervalMs = 5000) 
    # refresh root directory 
    wd_folders <- reactive({ 
     button() 
     basename(list.dirs(recursive = FALSE)) 
    }) 

    output$folderselection <- renderUI({ 
     selectInput('pick_a_folder', '', 
        choices = c('choose a folder', wd_folders() 
        ) 
     ) 
    }) 

    # dinamic file selection. find the file list after folder is choosen 
    output$fileselection <- renderUI({ 
     selectInput('pick_a_file', '', 
        selected = 'choose a file', 
        choices=c('choose a file', 
           basename(list.files(path = input$pick_a_folder,recursive=FALSE)))) 
    }) 
}) 
shinyApp(ui = ui, server = server)

来源

2017-02-20 13:47:20 GGamba

谢谢，我会看看你做了什么。 –

依赖闪亮的物体

回答

相关问题