https://cran.r-project.org/web/packages/periscope/vignettes/downloadablePlot-module.html

global.R

+invisible(sapply(list.files('src', full.names = TRUE), source))

panels/barplot-server.R

@@ -69,6 +69,7 @@ output$barplotUI <- renderUI({
     uiOutput("barplotNbTaxaUI"),
     uiOutput("barplotGridUI"),
     uiOutput("barplotXUI"),
+    #downloadButton('downloadPlot', 'Download Plot'),
     collapsedBox(verbatimTextOutput("barplotScript"), title = "RCode")
   )
 })
@@ -104,7 +105,7 @@ output$barplotScript <- renderText({
   return(glue_collapse(script, sep = "\n"))
 })
 
-output$barplot <- renderPlot({
+plotBarplot <- reactive({
   validate(
     need(data16S(), "Requires an abundance dataset"),
     need(input$barplotShowRank, "")
@@ -122,3 +123,16 @@ output$barplot <- renderPlot({
   }
   return(p)
 })
+
+callModule(plotDownload, "barplot" ,plotBarplot)
+
+# output$barplot <- renderPlot({plot()})
+
+# output$downloadPlot <- downloadHandler(
+#   filename = "barplot.png",
+#   content = function(file) {
+#     png(file)
+#     print(plot())
+#     dev.off()
+#   }
+# )

panels/barplot-ui.R

-barplot <-fluidPage(withLoader(plotOutput("barplot", height = 700)),
-                      uiOutput("barplotUI"))
+barplot <-fluidPage(plotDownloadUI("barplot"),
+                    #withLoader(plotOutput("barplot", height = 700)),
+                    uiOutput("barplotUI")
+                    )

src/download_module.R

+plotDownloadUI <- function(id, height = 400) {
+    ns <- NS(id)
+    tagList(
+        fluidRow(
+            plotOutput(ns('plot'), height = height)
+        ),
+        fluidRow(
+            column(
+                2, offset = 10,
+                downloadButton(ns("download_plot"), "Download figure")
+            )
+        )
+    )
+}
+
+plotDownload <- function(input, output, session, plotFun) {
+    output$plot <- renderPlot({
+        plotFun()
+    })
+    
+    output$download_plot <- downloadHandler(
+        filename = function() {
+            "plot.png"
+        },
+        content = function(file) {
+            ggsave(file, plotFun(), width = 16, height = 10.4)
+        }
+    )
+}