18  Live Dashboards

Here’s where everything comes together: the 3D viewer from the Viewer chapter on the left, live sensor charts from Linking Sensor Streams on the right, all in one Shiny app that refreshes automatically. This is what a digital twin dashboard looks like in R.

graph LR
  A[getToken] --> B[viewer3D\nAutoDesk Viewer]
  A --> C[Tandem API\nhttr2]
  C --> D[dygraph\ntime-series chart]
  B --> E[Shiny Dashboard]
  D --> E

18.1 Required Packages

install.packages(c("shiny", "dygraphs", "xts", "httr2"))

18.2 Helper: Fetch Stream Readings

Define a reusable function that the Shiny server calls reactively:

library(AutoDeskR)
library(httr2)
library(dygraphs)
library(xts)
library(shiny)

get_stream_readings <- function(facility_id, stream_id, hours_back = 24) {
  token <- getToken(
    id     = Sys.getenv("client_id"),
    secret = Sys.getenv("client_secret"),
    scope  = "data:read"
  )$content$access_token

  end_time   <- Sys.time()
  start_time <- end_time - hours_back * 3600
  resp <- request(
    paste0("https://tandem.autodesk.com/api/v1/twins/",
           facility_id, "/streams/", stream_id)
  ) |>
    req_url_query(
      start = format(start_time, "%Y-%m-%dT%H:%M:%SZ", tz = "UTC"),
      end   = format(end_time,   "%Y-%m-%dT%H:%M:%SZ", tz = "UTC")
    ) |>
    req_auth_bearer_token(token) |>
    req_perform()
  readings <- resp_body_json(resp)
  data.frame(
    timestamp = as.POSIXct(vapply(readings$values, `[[`, character(1), "t"),
                            format = "%Y-%m-%dT%H:%M:%SZ", tz = "UTC"),
    value     = vapply(readings$values, `[[`, numeric(1), "v"),
    stringsAsFactors = FALSE
  )
}

18.3 App Startup

Fetch the token and stream list once, before the UI and server are defined:

myEncodedUrn <- jsonlite::base64_enc(Sys.getenv("urn"))
myToken      <- getToken(id     = Sys.getenv("client_id"),
                         secret = Sys.getenv("client_secret"),
                         scope  = "data:read")$content$access_token
facilityId   <- "urn:adsk.dtdm:facility.abc123def456"

streams_resp <- request(
  paste0("https://tandem.autodesk.com/api/v1/twins/", facilityId, "/streams")
) |>
  req_auth_bearer_token(myToken) |>
  req_perform()
streams <- resp_body_json(streams_resp)

stream_choices <- setNames(
  vapply(streams, `[[`, character(1), "id"),
  vapply(streams, `[[`, character(1), "displayName")
)

18.4 UI Layout

Viewer on the left, controls and chart on the right:

ui <- fluidPage(
  titlePanel("Digital Twin Dashboard"),
  fluidRow(
    column(7,
      viewer3D(urn        = myEncodedUrn,
               token      = myToken,
               viewerType = "headless")
    ),
    column(5,
      selectInput("stream_id", "Sensor stream:",
                  choices = stream_choices),
      sliderInput("hours_back", "Time window (hours):",
                  min = 1, max = 168, value = 24, step = 1),
      dygraphOutput("sensor_plot", height = "320px"),
      tableOutput("stats_table")
    )
  )
)

18.5 Server Logic

A reactiveTimer polls Tandem every 60 seconds so the chart stays current without the user having to refresh the page:

server <- function(input, output, session) {

  auto_refresh <- reactiveTimer(60000)   # 60 seconds

  readings <- reactive({
    auto_refresh()   # re-run on the timer tick
    get_stream_readings(facility_id = facilityId,
                        stream_id   = input$stream_id,
                        hours_back  = input$hours_back)
  })

  output$sensor_plot <- renderDygraph({
    df   <- readings()
    ts   <- xts(df$value, order.by = df$timestamp)
    name <- names(stream_choices)[stream_choices == input$stream_id]
    dygraph(ts, main = name) |>
      dyRangeSelector() |>
      dyOptions(fillGraph = TRUE, fillAlpha = 0.15,
                drawGrid  = TRUE, colors   = "#367ABF") |>
      dyAxis("y", label = "Value")
  })

  output$stats_table <- renderTable({
    df <- readings()
    data.frame(
      Metric = c("Readings", "Mean", "Min", "Max"),
      Value  = c(nrow(df),
                 round(mean(df$value), 2),
                 round(min(df$value),  2),
                 round(max(df$value),  2))
    )
  }, striped = TRUE, bordered = TRUE, align = "lr")
}

shinyApp(ui, server)

Warning

The Shiny server fetches Tandem data from R, not from the user’s browser, so CORS restrictions don’t apply. The server process does need outbound HTTPS access to tandem.autodesk.com, so check this if you’re deploying on a restricted corporate network.

18.6 Deploying to shinyapps.io

Keep credentials out of the app source. Pass them as server environment variables at deploy time:

library(rsconnect)

deployApp(
  appDir     = ".",
  appName    = "twin-dashboard",
  appEnvVars = list(
    client_id     = Sys.getenv("client_id"),
    client_secret = Sys.getenv("client_secret"),
    urn           = Sys.getenv("urn")
  )
)