R闪光输入的记忆功能

Question

我有一个闪亮的应用程序，有很多输入文件要指定。每次我重新打开我的闪亮的应用程序时，我都需要再次指定所有它们。有没有办法让Shiny记住所选的文件？(不是通过在代码中写入默认值，而是通过单击保存按钮或类似的东西)。

Answer 1

您可以创建一个按钮，用于在单击时保存所有输入的值，还可以创建另一个按钮，用于使用保存的值更新输入。下面是一个最小的例子：

library(shiny)

# Global variables
path_to_save <- "save_param.RData"

ui <- fluidPage(

  titlePanel("Hello Shiny!"),
  sidebarLayout(

    sidebarPanel(
      sliderInput(inputId = "bins",
                  label = "Number of bins:",
                  min = 1,
                  max = 50,
                  value = 30),
      checkboxGroupInput(inputId = "color",
                         label = "Bins color",
                         choices = c("red", "blue", "green")),

      actionButton(inputId = "save",
                   label = "Save parameters"),
      tags$hr(),
      actionButton(inputId = "apply_save",
                   label = "Load saved parameters")

    ),

    mainPanel(
      plotOutput(outputId = "distPlot")
    )
  )
)

# Define server logic required to draw a histogram ----
server <- function(input, output, session) {

  output$distPlot <- renderPlot({

    x    <- faithful$waiting
    bins <- seq(min(x), max(x), length.out = input$bins + 1)

    hist(x, breaks = bins, col = input$color, border = "white",
         xlab = "Waiting time to next eruption (in mins)",
         main = "Histogram of waiting times")

  })

  observeEvent(input$save,{
    params <- list(bins = input$bins, color = input$color)
    save(params, file = path_to_save)
  })

  observeEvent(input$apply_save,{
    load(path_to_save) # of course you need to add verifications about the existence of the file
    updateSliderInput(session = session, inputId = "bins", min = 1, max = 50, value = params$bins)
    updateCheckboxGroupInput(session = session, inputId = "color", label = "Bins color", choices = c("red", "blue", "green"),
                        selected = params$color)
  })

}

shinyApp(ui, server)

你可以升级这个想法，可以节省几笔钱，给这些钱命名，用selectInput选择你想要的那个，等等。