Report Previewer

The Report previewer is an advanced shiny module designed for visualization, editing, and downloading of report cards. It extended the base modules introduced in the simpleReporter vignette, enhancing interactivity and user engagement with report content.

The report previewer is now implemented as a modal dialog that opens when a preview button is clicked, providing a streamlined user experience without requiring separate tabs.

The five essential steps for implementing the report previewer include integrating it within a shiny application. Key code segments are highlighted in ### REPORTER code blocks.

1. Add the preview button UI component to your app’s interface.
2. Integrate the UI components of the modules into the app’s UI.
3. Initialize reporter instance.
4. Create a reactive that must return a teal_card object. The teal_card object should be built step by step, assuming that it is empty at the beginning. Please note that the document page’s design is up to the developer’s imagination.
5. Invoke the servers with the Reporter instance and the function to create the teal_card instance.

The code added to introduce the reporter is wrapped in the ### REPORTER code blocks.

First, load the required packages:

library(shiny)
library(teal.reporter)
library(ggplot2)
library(rtables)
library(DT)
library(bslib)

A basic shiny app with the previewer module:

ui <- bslib::page_fluid(
  sidebarLayout(
    sidebarPanel(
      uiOutput("encoding")
    ),
    mainPanel(
      tabsetPanel(
        id = "tabs",
        tabPanel("Plot", plotOutput("dist_plot")),
        tabPanel("Table", verbatimTextOutput("table")),
        tabPanel("Table DataFrame", verbatimTextOutput("table2")),
        tabPanel("Table DataTable", DTOutput("table3"))
      )
    )
  )
)
server <- function(input, output, session) {
  output$encoding <- renderUI({
    shiny::tagList(
      ### REPORTER
      teal.reporter::add_card_button_ui("add_reporter", label = "Add Report Card"),
      tags$div(style = "margin-bottom: 0.5em;"), # empty separator
      teal.reporter::preview_report_button_ui("previewer"),
      ###
      if (input$tabs == "Plot") {
        sliderInput(
          "binwidth",
          "binwidth",
          min = 2,
          max = 10,
          value = 8
        )
      } else if (input$tabs %in% c("Table", "Table DataFrame", "Table DataTable")) {
        selectInput(
          "stat",
          label = "Statistic",
          choices = c("mean", "median", "sd"),
          "mean"
        )
      } else {
        NULL
      }
    )
  })
  plot <- reactive({
    req(input$binwidth)
    x <- mtcars$mpg
    ggplot(data = mtcars, aes(x = mpg)) +
      geom_histogram(binwidth = input$binwidth)
  })
  output$dist_plot <- renderPlot(plot())

  table <- reactive({
    req(input$stat)
    lyt <- basic_table() %>%
      split_rows_by("Month", label_pos = "visible") %>%
      analyze("Ozone", afun = eval(str2expression(input$stat)))
    build_table(lyt, airquality)
  })
  output$table <- renderPrint(table())

  table2 <- reactive({
    req(input$stat)
    data <- aggregate(
      airquality[, c("Ozone"), drop = FALSE], list(Month = airquality$Month), get(input$stat),
      na.rm = TRUE
    )
    colnames(data) <- c("Month", input$stat)
    data
  })
  output$table2 <- renderPrint(print.data.frame(table2()))
  output$table3 <- renderDT(table2())

  ### REPORTER
  reporter <- Reporter$new()

  # Optionally set reporter id to e.g. secure report reload only for the same app
  # The id is added to the downloaded file name.
  reporter$set_id("myappid")

  card_r <- reactive({
    card <- teal_card()
    card <- if (input$tabs == "Plot") {
      metadata(card, "title") <- "Plot Module"
      c(
        card,
        "## My plot",
        plot(),
        code_chunk(
          paste(
            "x <- mtcars$mpg",
            "ggplot2::ggplot(data = mtcars, ggplot2::aes(x = mpg)) +",
            paste0("ggplot2::geom_histogram(binwidth = ", input$binwidth, ")"),
            sep = "\n"
          )
        )
      )
    } else if (input$tabs == "Table") {
      metadata(card, "title") <- "Table Module rtables"
      c(
        card,
        "## My rtables",
        table,
        code_chunk(
          paste(
            "lyt <- rtables::basic_table() %>%",
            'rtables::split_rows_by("Month", label_pos = "visible") %>%',
            paste0('rtables::analyze("Ozone", afun = ', input$stat, ")"),
            "rtables::build_table(lyt, airquality)",
            sep = "\n"
          )
        )
      )
    } else if (input$tabs %in% c("Table DataFrame", "Table DataTable")) {
      metadata(card, "title") <- "Table Module DF"
      c(
        card,
        "## My Table DF",
        table2(),
        paste(
          "```",
          paste0(
            'data <- aggregate(airquality[, c("Ozone"), drop = FALSE], list(Month = airquality$Month), ',
            input$stat,
            ", na.rm = TRUE)"
          ),
          sprintf('colnames(data) <- c("Month", "%s")', input$stat),
          "data",
          "```",
          sep = "\n"
        )
      )
    }
  })
  teal.reporter::add_card_button_srv("add_reporter", reporter = reporter, card_fun = card_r)
  teal.reporter::preview_report_button_srv("previewer", reporter)
  ###
}

shinyApp(ui = ui, server = server)