add shiny example of crossfilter with scatterplot

Author: cpsievert

inst/examples/shiny/crossfilter_scatter/app.R

@@ -0,0 +1,39 @@
+library(shiny)
+library(plotly)
+library(dplyr)
+
+ui <- fluidPage(
+  plotlyOutput("bars"),
+  plotlyOutput("markers")
+)
+
+server <- function(input, output, session) {
+  
+  output$bars <- renderPlotly({
+    plot_ly(diamonds, x = ~depth, source = "bars") %>%
+      layout(
+        dragmode = "select",
+        selectdirection = "h"
+      )
+  })
+  
+  output$markers <- renderPlotly({
+    plot_ly(diamonds, x = ~carat, y = ~price, alpha = 0.2) %>%
+      toWebGL()
+  })
+  
+  observe({
+    brush <- event_data("plotly_brushing", source = "bars")
+    if (is.null(brush)) brush <- list(x = range(diamonds$depth))
+    
+    is_within <- between(diamonds$depth, brush$x[1], brush$x[2])
+    cols <- if_else(is_within, "rgba(31,119,180,0.2)", "transparent")
+    
+    plotlyProxy("markers", session) %>%
+      plotlyProxyInvoke("restyle", "marker.color", list(cols))
+  })
+  
+  
+}
+
+shinyApp(ui, server)