In vanheeringen-lab/learnr.proto: A set of LearnR Tutorials.

suppressPackageStartupMessages({
  library(learnr)     # 0.10.1.9006 (github)
  library(gradethis)  # 0.1.0.9004  (github)
  # library(...)
})

# configuration
options("tutorial.storage"="local")  # save progress in ~/.local/share/R/ see https://bit.ly/3oNP3kF
knitr::opts_chunk$set(echo = FALSE)
gradethis::gradethis_setup()

# data accessible to all exercises
# rdata = system.file("extdata", "week_n.Rdata", package = "learnr.proto")
# load(rdata)

# stop the app when the browser is closed (or refreshed*)
#   *there is **no way** to distinguish between refresh and browser (tab) closing
# this is required as closing the browser window prevents the timeout below from working.
session$onSessionEnded(stopApp)

# The timeout chunks stop the tutorial if it has been idle for too long
# Their purpose is to keep the server running smoothly

# Method: 
# This chunk (timeout1) sends a unique identifier "session_id" to timeout2.
# When the session has been running idle for longer than "timeoutSec" seconds,
# timeout2 will update shiny variable "input[[session_id]]" .
# This signal is then be used in timeout1 to stop the session.

# obtain the session's ID and send it to the javascript chunk
isolate({
  session_id <- sub('<environment: (.*)>', '\\1', capture.output(session$userData))
  session$sendCustomMessage("session_id", session_id)
})

# stop the tutorial when "input[[session_id]]" is updated
observeEvent(input[[session_id]], ignoreNULL=T, {
  write(paste0("\nTutorial terminated due to inactivity.\nRestart to continue where you left off!\n"), stderr())
  stopApp()
})

# source 1: https://shiny.rstudio.com/reference/shiny/latest/session.html
# source 2: https://stackoverflow.com/questions/18900955/get-environment-identifier-in-r

```{js timeout2} $(function() { var timeoutSec = 10*60; // <-- change as desired var idleTimer;

// receive this session's ID Shiny.addCustomMessageHandler("session_id", function(s_id) { session_id = s_id; // assigns the variable globally });

// update "input[[session_id]]" when called function onTimeout() { alert("Tutorial stopped due to inactivity.\nRestart to continue where you left off!") Shiny.setInputValue(session_id, "TRUE"); }

function startIdleTimer() { if (idleTimer) clearTimeout(idleTimer); idleTimer = setTimeout(onTimeout, timeoutSec * 1000); }

// (re)set timeout upon user input $(document).on('shiny:message shiny:inputchanged', startIdleTimer);

})();

// source 1: https://community.rstudio.com/t/keeping-track-of-idle-time-during-app-usage/1735 // source 2: https://bookdown.org/yihui/rmarkdown/language-engines.html#javascript-and-css

```{js open_links_in_new_tab}
// open all links starting with http(s) in a new tab
$(function() {
  var links = document.getElementsByTagName('a');
  for (var i = 0; i < links.length; i++) {
    if (/^(https?:)?\/\//.test(links[i].getAttribute('href'))) {
      links[i].target = '_blank';
    }
  }
})();

// source: https://yihui.org/en/2018/09/target-blank/

# log the first time a user starts this tutorial.

tutorial = "template"
log_path = "/scratch/fg_log"  # make this dir and set 777 permissions!

if (file.access(log_path, 7)[[1]] == 0 ){
  date = Sys.Date()
  user = basename(path.expand("~"))
  log_name = paste0(tutorial, "_", user, "_", date)
  log_file = file.path(log_path, log_name)

  logs = list.files(log_path)  # all currently existing logs
  substring = paste0(tutorial, "_", user)  # date is unimportant
  log_exists = any(lapply(logs, startsWith, substring) == TRUE)
  if (!log_exists){
    invisible(file.create(log_file))
    system(paste0("chmod 777 ", log_file))
  }
}

Attendance

Please fill in your name and student number below and hit "Submit Answer" (the button will then disappear). At the end of the tutorial, print your answers and upload the PDF to Brightspace.

question_text(
  "Enter your name & student number",
  placeholder = "name s123456",
  answer("Little nosey, aren't we?", correct=TRUE),
  incorrect=NULL,  # hide the red button
  allow_retry = FALSE  # prevent cheating
)

# alternative:
# https://stackoverflow.com/questions/63894794/create-an-open-ended-question-with-learnrtutorial-in-r

Chapter name

tutorial goes here

```{js print2pdf1, context="server"} // the following 2 chunks print the completed sections of the tutorial to PDF // uses "css/print2pdf.css" $(document).on('shiny:inputchanged', function(event) { if (event.name === 'print2pdf') { window.print(); } });

```r
# button can be placed anywhere in the tutorial
# suggested at the end of the tutorial as the tutorial should be completed first
actionButton("print2pdf", "Print page", style="opacity: .7; color: #000;")

vanheeringen-lab/learnr.proto documentation built on March 1, 2021, 11:10 p.m.