Question

第一次闪亮的用户，我想我已经完成了大部分设置。代码我从基于目录的数据库中检索某些数据。输出是一个csv文件，我希望能够直接从闪亮下载。

下面的代码是非常基本的：

需要inputed日期并分隔D / M / Y并创建搜索字词
还会创建表示不同文件的某些关键字以进行搜索
搜索特定文件夹并检索CSV。文件
然后，它仅检索标记为此文件中的inputs之一的数据
此数据应通过CSV或XLS格式的Shiny应用程序下载/ ouptuted

我的输入是：

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

输出是：

Forwards_Fund

这些已经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.R

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)

错误

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

编辑： - 更新

这是一个闪亮的应用程序，它从基于目录的数据库中检索CSV文件的名称。我将继续使用下载按钮升级它。

我的桌面上有一个名为EquilibriumWeeklyMacro的文件

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

它包含多个按日期排序的文件

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

在那里我有一个名为

XCP4P487FOFFET_20160315.CSV

请注意FOFFET_和20160315结尾

如果我在Shiny应用程序框中输入XCP4P487FOFFET_20160315.CSV，以下Shiny应用程序应该能够从该文件中检索2016-03-15。

除了最后一部分之外，下面的代码是有效的：

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

我知道问题出在上面。以下是该应用的代码：

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)

Answer 1

Shiny有一个名为downloadButton的小部件，可以找到文档here。

我已整合到您的应用中：

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)

Answer 2

这是一个带有操作按钮的示例程序，该按钮仅在单击时写入csv。不会将它集成到您的程序中，因为您的程序太大而且我没有您的数据，但您应该能够使用它：

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)

看起来像这样：

如何从按日期排序的基于目录的数据库导出.csv？

2 个答案: