downloadablePlot Shiny 模块在启动时分解了我的 shiny 应用程序

Question

我有下面的shiny应用程序，我想知道如何使用downloadablePlot Shiny 模块下载 plot。 当我启动该应用程序时，整个应用程序都崩溃了。

library(shiny)
library(periscope)
ui <- fluidPage(
  plotOutput("plot"),
  downloadablePlotUI("object_id1", 
                     downloadtypes = c("png", "csv"), 
                     download_hovertext = "Download the plot and data here!",
                     height = "500px", 
                     btn_halign = "left")
)

server <- function(input, output) {
  output$plot<-renderPlot(plot(iris))
  plotInput = function() {
    plot(iris)
  }
  callModule(downloadablePlot,
             "object_id1", 
             logger = ss_userAction.Log,
             filenameroot = "mydownload1",
             aspectratio = 1.33,
             downloadfxns = list(png = plotInput()),
             visibleplot = plotInput())
  
}

shinyApp(ui = ui, server = server)

Answer 1

将 plotInput 作为参数传递时，尝试删除plotInput之后的括号

library(shiny)
library(periscope)
ui <- fluidPage(
  plotOutput("plot"),
  downloadablePlotUI("object_id1",
                     downloadtypes = c("png", "csv"),
                     download_hovertext = "Download the plot and data here!",
                     height = "500px",
                     btn_halign = "left")
)

server <- function(input, output) {
  output$plot<-renderPlot(plot(iris))
  plotInput = function() {
    plot(iris)
  }
  callModule(downloadablePlot,
             "object_id1",
             logger = ss_userAction.Log,
             filenameroot = "mydownload1",
             aspectratio = 1.33,
             downloadfxns = list(png = plotInput),
             visibleplot = plotInput)

}

shinyApp(ui = ui, server = server)

在 shiny 中，当传递函数/反应时，你通常需要避免在它们后面附加() ，因为这样做会评估它们。 在上面的示例中，您返回的是plotInput的 output 而不是 function 本身