如何将数据从闪亮的应用程序写入exce / csv文件？恰好我想将股票价格值的值写入excel / csv文件

Posted 2023-01-12

我想将股票价格的值写入excel / csv文件。但是无法这样做。显示以下错误代码：如果没有活动的响应上下文，则不允许进行操作。 （您试图做只能从反应式表达式或观察器内部完成的操作。）。当我使用反应性数据（dataInput）时，错误消息显示为“无法强制将类'c（“ reactiveExpr”，“ reactive”））强制到data.frame

此代码附在此处。：

加载程序包----

library(shiny)
library(quantmod)
#edited the code.this can be run directly

# User interface ----
ui <- fluidPage(
  titlePanel("stockVis"),

  sidebarLayout(
    sidebarPanel(
      helpText("Select a stock to examine.

        Information will be collected from Yahoo finance."),
      textInput("symb", "Symbol", "SPY"),

      dateRangeInput("dates",
                     "Date range",
                     start = "2013-01-01",
                     end = as.character(Sys.Date())),

      br(),
      br(),

      checkboxInput("log", "Plot y axis on log scale",
                    value = FALSE)

      #checkboxInput("adjust",
      #"Adjust prices for inflation", value = FALSE)
    ),

    mainPanel(plotOutput("plot"), tableOutput("view")))



)


# Server logic
server <- function(input, output) 

  dataInput <- reactive(
    getSymbols(input$symb, src = "yahoo",
               from = input$dates[1],
               to = input$dates[2],
               auto.assign = FALSE)


  ) Blockquote
  output$plot <- renderPlot(

    chartSeries(dataInput(), theme = chartTheme("white"),
                type = "line", log.scale = input$log, TA = NULL)
  )

  output$view <- renderTable((dataInput() )
  , include.rownames = TRUE)
  #trying to export the data
  write.csv(dataInput(),row.names = TRUE)

`enter code here`

# Run the app
shinyApp(ui, server)

答案

在被动上下文中，一旦股票代码开始变化，它将尝试在运行Shiny应用程序和后立即执行代码。要允许文件仅在用户准备就绪时才写入，请将“反应性”更改为“观察事件”。添加了“运行”按钮以使其工作。复制并粘贴下面的代码。

顺便说一下，'write.csv'命令中省略了'file ='，该命令将csv文件滚动到控制台。

library(shiny)
library(quantmod)
#edited the code.this can be run directly

# User interface ----
ui <- fluidPage(
  titlePanel("stockVis"),

  sidebarLayout(
    sidebarPanel(
      helpText("Select a stock to examine.

        Information will be collected from Yahoo finance."),
      textInput("symb", "Symbol", "SPY"),

      dateRangeInput("dates",
                     "Date range",
                     start = "2013-01-01",
                     end = as.character(Sys.Date())),

      br(),
      br(),

      checkboxInput("log", "Plot y axis on log scale",
                    value = FALSE),

      #checkboxInput("adjust",
      #"Adjust prices for inflation", value = FALSE),
      actionButton(inputId = "run",label="Run"),
    ),

    mainPanel(plotOutput("plot"), tableOutput("view")))

)

# Server logic
server <- function(input, output) 

  dataInput <- function() 
    getSymbols(input$symb, src = "yahoo",
               from = input$dates[1],
               to = input$dates[2],
               auto.assign = FALSE)
  

  observeEvent (input$run, 

   output$plot <- renderPlot(

    chartSeries(dataInput(), theme = chartTheme("white"),
                type = "line", log.scale = input$log, TA = NULL)
    )

    output$view <- renderTable((dataInput() )
    , include.rownames = TRUE)
    #trying to export the data
    write.csv(dataInput(),row.names = TRUE)

  )

# Run the app

shinyApp(ui, server)