R 如何从按日期排序的基于目录的数据库中导出.csv？

第一次闪亮的用户，我想我有这个设置的大部分。我的代码从基于目录的数据库中检索某些数据。输出是一个csv文件，我希望能够直接从shiny下载

下面的代码非常基本：

它接受

输入的
日期，分离D/M/Y并创建搜索词

还创建了表示不同文件的某些关键字以进行搜索

它搜索特定文件夹并检索CSV。文件

然后，它仅从该文件检索标记为

输入之一的数据

此数据应可通过Shining app以CSV或XLS格式下载/

并输出

我的意见是：

inputId=“NaVDate”

=这是日期（用于搜索和检索.csv）

inputId=“FundID”

=这是在步骤4中对数据进行排序的ID

输出为：

Forwards_Fund

这些已包含在下面的代码中：

UI.R

library(shiny)


ui <- fluidPage(

  # Date input by user
  dateInput(inputId = "NaVDate", label = "Select NaV Date", 
            format = "yyyy-mm-dd", startview = "month", weekstart = 0),
  # 
  textInput(inputId = "FundID", label = "Enter Fund ID (Numeric Only)", value = "", width = NULL, placeholder = NULL),

   downloadButton("downloadData", "Download")


)

server <- function(input, output) {

  # extract inputed month / year / day and vectorize ( inputed in YYYY-MM-DD format)


  timestrip   <- reactive({unlist(strsplit(as.character(input$NaVDate), split = ""))}) 


  year   <- paste(timestrip[1], timestrip[2], timestrip[3], timestrip[4], sep = "")
  month  <- paste(timestrip[6], timestrip[7], sep = "")
  day    <- paste(timestrip[9], timestrip[10], sep = "")

  Date      = paste(year, month, day, sep = "")


  # create directory search criteria for the required files - eg.("XCP4P487FOFFET_20160315.CSV")

  Forwards  = paste0("*FOFFET_", Date, ".CSV$")


  # create main directory file path

  file_path <- paste0("C:/Users/dell Optiplex/Desktop/Equilibrium Weekly Macro/", year,"/", month) 


  # Search through file_path for criteria and create individual .csv filepath

  Forwards_CSV_path  = list.files(file_path, 
                                  pattern = Forwards, full.names=TRUE, 
                                  ignore.case=TRUE)


  # Read Data from CSV files

  Forwards_data = do.call(rbind, lapply(Forwards_CSV_path, function(x) read.csv(x, sep = ";", stringsAsFactors = FALSE)))


  # Extract data from the inputed fund code (input$FundID) 

  Forwards_Fund  <- reactive({
    Forwards_data[which(Forwards_data$Fund.Code == input$FundID),]
  })

  ## download above data from shiny app

output$downloadData <- downloadHandler(
    filename = function() {
      paste('data-', Sys.Date(), '.csv', sep='')
    },
    content = function(con) {
      write.csv(Forwards_Fund(), con)
    }
  )


}

shinyApp(server = server, ui = ui)

Listening on http://127.0.0.1:6132
Warning: Error in [: object of type 'closure' is not subsettable
Stack trace (innermost first):
    44: paste
    43: server [#9]
     4: <Anonymous>
     3: do.call
     2: print.shiny.appobj
     1: print
Error in timestrip[1] : object of type 'closure' is not subsettable

它包含多个按日期排序的文件

C:/Users/dell Optiplex/Desktop/EquilibriumWeeklyMacro/2016/03/

在那里我有一个CSV文件叫做

XCP4P487FOFFET_20160315.CSV

请注意

FOFFET_

和

20160315

结尾

如果我在闪亮应用程序框中输入

2016-03-15

，以下闪亮应用程序应该能够从该文件中检索

XCP4P487FOFFET_20160315.CSV

除最后一部分外，以下代码适用：

output$ForwardText  =  renderText({list.files(as.character(FileDirectory()), 
                                                     pattern = as.character(ForwardSearchString()), full.names=TRUE, 
                                                     ignore.case=TRUE)
                                                      })

我知道问题就在上面。 以下是应用程序的代码：

library(shiny)


# XCP4P487FOFFET_20160315.CSV
# C:/Users/dell Optiplex/Desktop/EquilibriumWeeklyMacro/2016/03/

ui <- fluidPage(

  # Date input by user

  dateInput(inputId = "NaVDate", label = "Select NaV Date",
            format = "yyyy-mm-dd", startview = "month", weekstart = 0),

  textOutput("ForwardText")

)



  server <- function(input, output) {



    DateInput <-       reactive({format(as.Date(input$NaVDate), "%Y%m%d")})


    FileDirectory <- reactive({paste("C:/Users/dell Optiplex/Desktop/EquilibriumWeeklyMacro/",
                                     substr(as.character(DateInput()), 1, 4), "/",
                                     substr(as.character(DateInput()), 5, 6),"/", sep = "") 
                                      })
    # Search String 

    ForwardSearchString <- reactive({paste("FOFFET_", as.character(DateInput()), ".CSV")})

    # Search through file_path for criteria and create individual .csv filepath


   output$ForwardText  =  renderText({list.files(as.character(FileDirectory()), 
                                                 pattern = as.character(ForwardSearchString()), full.names=TRUE, 
                                                 ignore.case=TRUE)
                                                  })

  }

shinyApp(server = server, ui = ui)

库（闪亮）
#XCP4P487FOFFET_20160315.CSV
#C:/Users/dell Optiplex/Desktop/equiriumweeklymacro/2016/03/
ui这里是一个示例程序，它带有一个操作按钮，只有在单击该按钮时才会写入csv。不打算将其集成到您的程序中，因为您的程序太大，而且我没有您的数据，但您应该能够处理以下问题：

library(shiny)
library(ggplot2)
u <- shinyUI(fluidPage(
  titlePanel("Simple Shiny Input"),

  sidebarLayout(position = "left",
                sidebarPanel( 
                              actionButton("savebutton", "Save Data"),
                              sliderInput("cnt","Count:",100,1000,500,5)
                ),
                mainPanel(plotOutput('stdplot'))
  )
))
s <- shinyServer(function(input, output) 
{
  histdata <- reactive({
      set.seed(1234)
      df <- data.frame(x=rnorm(input$cnt))
    } )
  output$stdplot = renderPlot({
      qplot(data=histdata(),x,fill=I("blue"),bins=30)
    })
  savedata <- observe({ 
        input$savebutton
        if (input$savebutton>0){
           write.csv(histdata(),"histo.csv")
        }
      })
  })
shinyApp(ui=u,server=s)

库（闪亮）
图书馆（GG2）
uShiny有一个用于此的小部件，称为
downloadButton
，可以找到文档

我已集成到您的应用程序中：

library(shiny)


ui <- fluidPage(

  # Date input by user
  dateInput(inputId = "NaVDate", label = "Select NaV Date", 
            format = "yyyy-mm-dd", startview = "month", weekstart = 0),
  # 
  textInput(inputId = "FundID", label = "Enter Fund ID (Numeric Only)", value = "", width = NULL, placeholder = NULL),

  downloadButton("downloadData", "Download")

)

server <- function(input, output) {

  # extract inputed month / year / day and vectorize ( inputed in YYYY-MM-DD format)


  timestrip   <- reactive({unlist(strsplit(as.character(input$NaVDate), split = ""))}) 

  Forwards_Fund  <- reactive({
    year   <- paste(timestrip()[1], timestrip()[2], timestrip()[3], timestrip()[4], sep = "")
    month  <- paste(timestrip()[6], timestrip()[7], sep = "")
    day    <- paste(timestrip()[9], timestrip()[10], sep = "")

    Date      = paste(year, month, day, sep = "")


    # create directory search criteria for the required files - eg.("XCP4P487FOFFET_20160315.CSV")

    Forwards  = paste0("*FOFFET_", Date, ".CSV$")


    # create main directory file path

    file_path <- paste0("C:/Users/dell Optiplex/Desktop/Equilibrium Weekly Macro/", year,"/", month) 


    # Search through file_path for criteria and create individual .csv filepath

    Forwards_CSV_path  = list.files(file_path, 
                                  pattern = Forwards, full.names=TRUE, 
                                  ignore.case=TRUE)


    # Read Data from CSV files

    Forwards_data = do.call(rbind, lapply(Forwards_CSV_path, function(x) read.csv(x, sep = ";", stringsAsFactors = FALSE)))


    # Extract data from the inputed fund code (input$FundID) 


    Forwards_data[which(Forwards_data$Fund.Code == input$FundID),]
  })

  output$downloadData <- downloadHandler(
    filename = function() {
      paste('data-', Sys.Date(), '.csv', sep='')
    },
    content = function(con) {
      write.csv(Forwards_Fund(), con)
    }
  )

}

shinyApp(server = server, ui = ui)

库（闪亮）
ui
write.csv
有什么问题？或者你所说的“下载”到底是什么意思。write.csv可以工作，但是这个闪亮的应用程序会被不熟悉R的人使用。我需要在我闪亮的应用程序中有一个可点击的按钮来导出6个csv文件。这与
数据库
没有真正的关系。也许
data.frame
嗨，迈克，谢谢你的回答。虽然有帮助，但保存数据代码与输入的大小有关。我不确定这正是我需要的。一两天后再来，如果你有时间，我会悬赏的。这是一个漫长的计划，但每件事都做了6次。我已将代码缩短为只包含1个变量，而不是6个。没问题，尽管我不确定您的语句“我们的保存数据代码与您的一个输入的大小相关”是什么意思。猜猜看，我会说你的意思是
histdata
对
input$cnt
的依赖性。然而，这是偶然的，本例的重点只是说明如何使用
actionButton
触发数据帧（或多个）的保存。我得到以下错误：
正在侦听http://127.0.0.1:6132 警告：[：类型为“closure”的对象不是子可附加堆栈跟踪中的错误（最里面的第一个）：44:粘贴43:server[#9]4:3:do.call 2:print.shinny.appobj 1:timestrip中的打印错误[1]：类型为“closure”的对象不可子集
您认为我是否正确地使用了
反应式
函数和上面的
输入$FundID/input$NaVDate
？很好，我自己从未使用过
下载按钮
我会尝试一下。@AlexBădoi是的，看起来您使用的反应式表达式不正确，请ee my edits.mkemp看起来您删除了
远期基金
向量，因此进入
输出$downloadData的输出实际上不再存在于代码中。另外还有一些额外的括号留在
}
。我不确定这是否完全正确。
library(shiny)


ui <- fluidPage(

  # Date input by user
  dateInput(inputId = "NaVDate", label = "Select NaV Date", 
            format = "yyyy-mm-dd", startview = "month", weekstart = 0),
  # 
  textInput(inputId = "FundID", label = "Enter Fund ID (Numeric Only)", value = "", width = NULL, placeholder = NULL),

  downloadButton("downloadData", "Download")

)

server <- function(input, output) {

  # extract inputed month / year / day and vectorize ( inputed in YYYY-MM-DD format)


  timestrip   <- reactive({unlist(strsplit(as.character(input$NaVDate), split = ""))}) 

  Forwards_Fund  <- reactive({
    year   <- paste(timestrip()[1], timestrip()[2], timestrip()[3], timestrip()[4], sep = "")
    month  <- paste(timestrip()[6], timestrip()[7], sep = "")
    day    <- paste(timestrip()[9], timestrip()[10], sep = "")

    Date      = paste(year, month, day, sep = "")


    # create directory search criteria for the required files - eg.("XCP4P487FOFFET_20160315.CSV")

    Forwards  = paste0("*FOFFET_", Date, ".CSV$")


    # create main directory file path

    file_path <- paste0("C:/Users/dell Optiplex/Desktop/Equilibrium Weekly Macro/", year,"/", month) 


    # Search through file_path for criteria and create individual .csv filepath

    Forwards_CSV_path  = list.files(file_path, 
                                  pattern = Forwards, full.names=TRUE, 
                                  ignore.case=TRUE)


    # Read Data from CSV files

    Forwards_data = do.call(rbind, lapply(Forwards_CSV_path, function(x) read.csv(x, sep = ";", stringsAsFactors = FALSE)))


    # Extract data from the inputed fund code (input$FundID) 


    Forwards_data[which(Forwards_data$Fund.Code == input$FundID),]
  })

  output$downloadData <- downloadHandler(
    filename = function() {
      paste('data-', Sys.Date(), '.csv', sep='')
    },
    content = function(con) {
      write.csv(Forwards_Fund(), con)
    }
  )

}

shinyApp(server = server, ui = ui)