track_usage {shinylogs}

Track usage of a Shiny app

Description

Used in Shiny server it will record all inputs and output changes and errors that occurs through an output.

Usage

track_usage(
  storage_mode,
  what = c("session", "input", "output", "error"),
  exclude_input_regex = NULL,
  exclude_input_id = NULL,
  on_unload = FALSE,
  app_name = NULL,
  exclude_users = NULL,
  get_user = NULL,
  dependencies = TRUE,
  session = getDefaultReactiveDomain()
)

Arguments

storage_mode

Storage mode to use : store_json(), store_rds(), store_sqlite() or store_null().

what

Elements to record between "session", "input", "output" and "error".

exclude_input_regex

Regular expression to exclude inputs from tracking.

exclude_input_id

Vector of inputId to exclude from tracking.

on_unload

Logical, save log when user close the browser window or tab, if TRUE it prevent to create shinylogs input during normal use of the application, there will be created only on close, downside is that a popup will appear asking to close the page.

app_name

Name of the app as a character string. If NULL, basename(getwd()) (name of the folder where application is located) is used.

exclude_users

Character vectors of user for whom it is not necessary to save the log.

get_user

A function to get user name, it should return a character and take one argument: the Shiny session.

dependencies

Load dependencies in client, can be set to FALSE if use_tracking() has been called in UI.

session

The shiny session.

Note

The following inputs will be accessible in the server:

• .shinylogs_lastInput : last input used by the user

• .shinylogs_input : all inputs send from the browser to the server

• .shinylogs_error : all errors generated by outputs elements

• .shinylogs_output : all outputs generated from the server

• .shinylogs_browserData : information about the browser where application is displayed.

Examples

# Save logs on disk ----------------------------------

if (interactive()) {

  # temporary directory for writing logs
  tmp <- tempdir()

  # when app stop,
  # navigate to the directory containing logs
  onStop(function() {
    browseURL(url = tmp)
  })

  # Classic Iris clustering with Shiny
  ui <- fluidPage(

    headerPanel("Iris k-means clustering"),

    sidebarLayout(
      sidebarPanel(
        selectInput(
          inputId = "xcol",
          label = "X Variable",
          choices = names(iris)
        ),
        selectInput(
          inputId = "ycol",
          label = "Y Variable",
          choices = names(iris),
          selected = names(iris)[[2]]
        ),
        numericInput(
          inputId = "clusters",
          label = "Cluster count",
          value = 3,
          min = 1,
          max = 9
        )
      ),
      mainPanel(
        plotOutput("plot1")
      )
    )
  )

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

    # Store JSON with logs in the temp dir
    track_usage(
      storage_mode = store_json(path = tmp)
    )

    # classic server logic

    selectedData <- reactive({
      iris[, c(input$xcol, input$ycol)]
    })

    clusters <- reactive({
      kmeans(selectedData(), input$clusters)
    })

    output$plot1 <- renderPlot({
      palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
                "#FF7F00", "#FFFF33", "#A65628", "#F781BF", "#999999"))

      par(mar = c(5.1, 4.1, 0, 1))
      plot(selectedData(),
           col = clusters()$cluster,
           pch = 20, cex = 3)
      points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
    })

  }

  shinyApp(ui, server)

}

# Logs in console & special inputs ------------------------

if (interactive()) {
  library(shiny)
  library(shinylogs)

  ui <- fluidPage(
    tags$h2("Record inputs change"),
    fluidRow(
      column(
        width = 3,
        selectInput(
          inputId = "select",
          label = "Select input",
          choices = month.name
        ),
        numericInput(
          inputId = "numeric",
          label = "Numerci input",
          value = 4,
          min = 0, max = 20
        ),
        checkboxGroupInput(
          inputId = "checkboxGroup",
          label = "Checkbox group input",
          choices = LETTERS[1:5]
        ),
        sliderInput(
          inputId = "slider",
          label = "Slider input",
          min = 0, max = 100, value = 50
        )
      ),
      column(
        width = 9,
        tags$b("Last input triggered:"),
        verbatimTextOutput(outputId = "last_input"),
        tags$b("All inputs:"),
        verbatimTextOutput(outputId = "all_inputs")
      )
    )
  )

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

    # dont store on disk, just show in R console
    track_usage(
      storage_mode = store_null()
    )

    # last input triggered
    output$last_input <- renderPrint({
      input$.shinylogs_lastInput
    })

    # all inputs that have changed
    output$all_inputs <- renderPrint({
      input$.shinylogs_input
    })

  }

  shinyApp(ui, server)
}