在 shinyapp 中显示来自 .csv 的 textInput 的反应值

Question

我正在开发一个 shinyapp，用于以交互方式生成 table，其中包含文件名和每个文件的一些新文本或评论。目前它按照以下步骤工作：
1. 选择文件夹
2. 使用文件名创建 .csv (if none)
.csv 的名称遵循模式 "subfolderName".csv
3. 使用 selectInput 选项选择文件名
4. 将您对每一行（文件）的评论添加到 .csv 文件中第二列名为 "comments"

一些我无法做到的期望行为：
- 在文本字段 (commentwritten) 中显示当前所选文件名（保存在 .csv 中）的先前评论（如果有）。我也尝试了 updateTextInput 但没有用。

#save as app.R
library(shiny)
library(shinyFiles)
library(shinyBS)
library(dplyr)
ui <- fluidPage(sidebarLayout(
  sidebarPanel(
    shinyDirButton("dir", "1. Choose directory", "Upload")
    ,br(),br()
    ,  bsButton("submit","2. Create or reset .csv", style="warning")
    ,br(),br()
    , uiOutput("fileinput")
    , uiOutput("uitextinput") # this is not showing existing comments

    ,  bsButton("addname","4. Add comment", style="warning")
  ),
  mainPanel(
    h4("Selected folder"),
    verbatimTextOutput("dirtext"), br(),
    h4("Files in that dir"),
    verbatimTextOutput("files"),
    textOutput("result")
  )
)) 

path1<-"~"

server <- function(input, output, session) {
  output$result<-renderText({
    t<- reac$message
  })

  shinyDirChoose(input, 'dir', roots = c(home = path1) )
  reacdir <- reactive(input$dir)
  output$dirtext <- renderPrint(c(path(),current() ) )

  path <- reactive({
    home <- normalizePath(path1)
    file.path(home, paste(unlist(reacdir()$path[-1]), collapse = .Platform$file.sep))
  })

  current<-reactive({
    a<-sub('.*\/', '', path() )  
    b<-paste("current subdir:",a)
  })

  reac <- reactiveValues(comment=NULL, df2=NULL)

  #not WORKING
  output$uitextinput<-renderUI(
    textInput("commentwritten","Comment for file", reac$comment)
  )

  # GET current .csv file with comments and load the comment to reac$comment , Not working
  observe({
    validate(
      need(try(any(class(reactiveFileReader(1000, session, paste0(path(),"/",sub('.*\/', '', path() ),".csv") , 
                                            read.csv()))=="data.frame")==TRUE), "Wait 801")
    )       
    reac$df2<-  reactiveFileReader(1000, session, paste0(path(),"/",sub('.*\/', '', path() ),".csv") , read.csv, stringsAsFactors=FALSE)
    reac$comment<-reac$df2$comment[match(input$file, reac$df2$name)]
  })

  filedata<-reactive({
    filenames<-  list.files(path())
    filedata<-data.frame(name=filenames)
  })

  # button 2. creating the csv file
  observeEvent(input$submit,{
    write.csv(filedata(), file =paste0(path(),"/",sub('.*\/', '', path() ),".csv")  , row.names = FALSE ) 
  })

  #step 3
  output$fileinput<-renderUI(
    div(style="width: 100%; margin: 0 0;",
        selectInput("file", "3. Select filename to add details", filedata()$name)
    )
  )

  #step 4, adding a comment to the .csv 
  observeEvent(input$addname , {
    if(file.exists(paste0(path(),"/",sub('.*\/', '', path() ),".csv")) ){
    dfnameadded <- reactive({
      originaldf<-reactiveFileReader(1000, session, paste0(path(),"/",sub('.*\/', '', path() ),".csv") , read.csv, stringsAsFactors=FALSE)
      filetoadd <- data.frame(name=input$file , stringsAsFactors = FALSE)
      filetoadd$comment<-input$commentwritten
      l<-list(originaldf(),filetoadd)#
      dfadded<- Reduce(bind_rows, l)
      dfadded<-dfadded %>%
        group_by(name) %>%
        summarise(comment = paste0(na.omit(comment[length(comment)]), collapse = "; ") )
      dfadded
    })
    tryCatch(write.csv(dfnameadded(), file =paste0(path(),"/",sub('.*\/', '', path() ),".csv")  , row.names = FALSE ), 
             error = function(e) {print(paste("create .csv first")) ; "create .csv first" } )
    reac$message<-"comment added"
    }
    else
    {
    reac$message<-"create .csv first"  
    }
  })

  output$files <- renderPrint(list.files(path()))
} # end server 
shinyApp(ui, server)

Answer 1

试试这个：

reac <- reactiveValues(comment <- NULL, df <- NULL)
textInput("namewritten","Comment for photo",placeholder= if(is.null(reac$comment)){"No Comments"}else{reac$comment})

我也会将 df 设为 reactiveValue。您正在使用 observe 基本上调用反应函数，但 observe 不会 return 任何值，因此 reac$comment 不会 returned.

Answer 2

我想到了这个解决方案正在替换

  #not WORKING
  # output$uitextinput<-renderUI(
  #   textInput("commentwritten","Comment for file", reac$comment)
  # )

与：

  observeEvent(input$file , {
    if(file.exists(paste0(path(),"/",sub('.*\/', '', path() ),".csv")) ){
      originaldf<-reactiveFileReader(1000, session, paste0(path(),"/",sub('.*\/', '', path() ),".csv"), read.csv, stringsAsFactors=FALSE)
      reac$df<-originaldf()
      output$uitextinput<-renderUI({          
        textInput("commentwritten","Comment for file",
                  reac$df$comment[match(input$file, reac$df$name)]
        )
      }) 
    }
    else{"index file does not exist, create with button 2."}
  })

在 shinyapp 中显示来自 .csv 的 textInput 的反应值

show a reactive value for textInput from a .csv in a shinyapp

r

dataframe

shiny

reactive