Hack to animate a series of DiagrammeR graphs.

DiagrammeRanimate.r

# Animation not yet possible natively in DiagrammeR: https://github.com/rich-iannone/DiagrammeR/issues/8
# so this simple hack for Shiny is based on https://stackoverflow.com/questions/27194893/reset-animation-in-shiny-r-studio#27224900

library(shiny)
library(DiagrammeRsvg)
library(DiagrammeR)

ui <- (fluidPage(
  # Application title
  headerPanel("Diagrammer Animation"),
  
  sidebarPanel(actionButton("goButton", "Go!")),
  mainPanel(
    plotOutput(outputId = "tsplot")
    ,
    grVizOutput('diagram',
                width = "100%",
                height = "500px")
  )
))

server <- (function(input, output, session) {
  # initialize reactive values
  ts <- reactiveValues(counter = 1)
  
  
  output$diagram <- renderGrViz({
    graph_1 <-
      create_graph() %>%
      add_path(n = 2)
    
    graph_2 <-
      create_graph() %>%
      add_cycle(n = 33)
    
    graph_3 <-
      create_graph() %>%
      add_star(n = 6)
    
    # Create an empty graph series
    # and add the graphs
    series <-
      create_graph_series() %>%
      add_graph_to_graph_series(graph = graph_1) %>%
      add_graph_to_graph_series(graph = graph_2) %>%
      add_graph_to_graph_series(graph = graph_3)
    
    render_graph_from_graph_series(graph_series = series,
                                   graph_no = ts$counter)
  })
  
  
  observe({
    isolate({
      ts$counter = ts$counter + 1
      if (ts$counter > 3)
        ts$counter = 1
    })
    if (((isolate(ts$counter) < 100)) & (input$goButton > 0)) {
      invalidateLater(2000, session)
    }
    
  })
  
  
})

runApp(list(ui = ui, server = server))