async example, thanks @jcheng5

Author: cpsievert

inst/examples/shiny/async/app.R

@@ -0,0 +1,42 @@
+library(shiny)
+library(plotly)
+library(ggplot2)
+library(promises)
+library(future)
+plan(multisession)
+
+ui <- fluidPage(
+  plotlyOutput("plot1"),
+  plotlyOutput("plot2"),
+  plotlyOutput("plot3"),
+  plotlyOutput("plot4")
+)
+
+server <- function(input, output, session) {
+  output$plot1 <- renderPlotly({
+    # Async plot_ly
+    future({ Sys.sleep(2); cars }) %...>%
+      plot_ly(x = ~speed, y = ~dist, type = "scatter", mode = "markers")
+  })
+  
+  output$plot2 <- renderPlotly({
+    # Async ggplotly
+    future({ Sys.sleep(2); mtcars }) %...>%
+    { ggplot(., aes(hp, mpg)) + geom_point() } %...>%
+      ggplotly()
+  })
+  
+  output$plot3 <- renderPlotly({
+    # Not async
+    plot_ly(iris, x = ~Sepal.Length, y = ~Sepal.Width,
+            type = "scatter", mode = "markers")
+  })
+  
+  output$plot4 <- renderPlotly({
+    # Ensure errors are handled properly (should be blank)
+    future({}) %...>%
+    { req(FALSE) }
+  })
+}
+
+shinyApp(ui, server)