Polyglot UI

.Rbuildignore

@@ -16,6 +16,7 @@
 rsconnect/
 ^\.github/
 ^inst/tutorials/.*\.html$
+^inst/tutorials/.*\.sqlite$
 ^revdep$
 ^LICENSE\.md$
 ^cran-comments\.md$

.gitignore

@@ -12,6 +12,7 @@ issues
 
 # html tutorial output
 inst/tutorials/*/*.html
+inst/tutorials/*/*.sqlite
 
 # deployment output
 rsconnect/

NEWS.md

@@ -17,6 +17,7 @@ learnr (development version)
 * Added a new `tutorial_options()`, namely `exercise.error.checker`, for customizing feedback when exercise submission code produces an evaluation error. This option accepts a function with the same arguments as `exercise.checker`. Use `gradethis::grade_learnr_error()` for a sensible default for this option. ([#403](https://github.com/rstudio/learnr/pull/403))
 * Added an event handler system, with the functions `event_register_handler()` and `one_time()`. There is also a new event `"section_viewed"`, which is triggered when a new section becomes visible. ([#398](https://github.com/rstudio/learnr/pull/398))
 * Previously, when a question submission was reset, it would be recorded as a `"question_submission"` event with the value `reset=TRUE`. Now it a separate event, `"reset_question_submission"`. ([#398](https://github.com/rstudio/learnr/pull/398))
+* Added a new `polyglot` tutorial to learnr. This tutorial displays mixing R, python, and sql exercises. See [`run_tutorial("polyglot", "learnr")`](https://learnr-examples.shinyapps.io/polyglot) for a an example. ([#397](https://github.com/rstudio/learnr/pull/397))
 
 ## Minor new features and improvements
 
@@ -27,6 +28,8 @@ learnr (development version)
 * Added error handling when user specifies a non-existent label for `exercise.setup` option with an error message. ([#390](https://github.com/rstudio/learnr/pull/390))
 * We no longer forward the checker code to browser (in html), but instead cache it. ([#390](https://github.com/rstudio/learnr/pull/390))
 * We no longer display an invisible exercise result warning automatically. Instead, authors must set the exercise chunk option `exercise.warn_invisible = TRUE` to display an invisible result warning message. ([#373](https://github.com/rstudio/learnr/pull/373))
+* With the addition of multi-language support, the exercise's execution language is displayed in the top left corner of the exercise. This can be overwritten by setting the chunk option `exercise.cap.engine`. ([#397](https://github.com/rstudio/learnr/pull/397))
+* `engine` is now passed to the `exercise.checker` to help distinguish what language is being checked in the exercise. ([#397](https://github.com/rstudio/learnr/pull/397))
 
 ## Bug fixes
 

R/exercise.R

@@ -210,7 +210,8 @@ evaluate_exercise <- function(exercise, envir, evaluate_global_setup = FALSE) {
       envir_result = NULL,
       evaluate_result = NULL,
       envir_prep = envir_prep,
-      last_value = NULL
+      last_value = NULL,
+      engine = exercise$engine
     )
     if (is_exercise_result(checker_feedback)) {
       return(checker_feedback)
@@ -232,7 +233,8 @@ evaluate_exercise <- function(exercise, envir, evaluate_global_setup = FALSE) {
       envir_result = envir,
       evaluate_result = rmd_results$evaluate_result,
       envir_prep = envir_prep,
-      last_value = rmd_results$last_value
+      last_value = rmd_results$last_value,
+      engine = exercise$engine
     )
   }
 
@@ -246,7 +248,7 @@ evaluate_exercise <- function(exercise, envir, evaluate_global_setup = FALSE) {
 
 try_checker <- function(exercise, name, check_code, envir_result,
                         evaluate_result, envir_prep, last_value,
-                        html_output) {
+                        engine) {
   checker_func <- tryCatch(
     get_checker_func(exercise, name, envir_prep),
     error = function(e) {
@@ -267,7 +269,8 @@ try_checker <- function(exercise, name, check_code, envir_result,
     envir_result = envir_result,
     evaluate_result = evaluate_result,
     envir_prep = envir_prep,
-    last_value = last_value
+    last_value = last_value,
+    engine = engine
   )
   # Throw better error messaging if the checker function signature is ill-defined
   missing_args <- setdiff(names(args), checker_args)
@@ -402,7 +405,8 @@ render_exercise <- function(exercise, envir, envir_prep) {
         envir_result = envir,
         evaluate_result = evaluate_result,
         envir_prep = envir_prep,
-        last_value = e
+        last_value = e,
+        engine = exercise$engine
       )
       if (is_exercise_result(checker_feedback)) {
         return(checker_feedback)

R/knitr-hooks.R

@@ -234,9 +234,11 @@ install_knitr_hooks <- function() {
         completion  <- as.numeric(options$exercise.completion %||% 1 > 0)
         diagnostics <- as.numeric(options$exercise.diagnostics %||% 1 > 0)
         startover <- as.numeric(options$exercise.startover %||% 1 > 0)
-        caption <- ifelse(is.null(options$exercise.cap), "Code", options$exercise.cap)
+        caption <- options[["exercise.cap"]] %||% "Code"
+        engine_caption <- options[["exercise.cap.engine"]] %||% options$engine %||% ""
         paste0('<div class="tutorial-', class,
                '" data-label="', options$label,
+               '" data-engine="', engine_caption,
                '" data-caption="', caption,
                '" data-completion="', completion,
                '" data-diagnostics="', diagnostics,

docs/exercises.Rmd

@@ -19,18 +19,22 @@ Exercises are interactive R code chunks that allow readers to directly execute R
 <td>Caption for exercise chunk (defaults to "Code")</td>
 </tr>
 <tr class="even">
+<td><code>exercise.cap.engine</code></td>
+<td>Caption for exercise chunk engine (defaults to the chunk engine value)</td>
+</tr>
+<tr class="odd">
 <td><code>exercise.eval</code></td>
 <td>Whether to pre-evaluate the exercise so the reader can see some default output (defaults to <code>FALSE</code>).</td>
 </tr>
-<tr class="odd">
+<tr class="even">
 <td><code>exercise.lines</code></td>
 <td>Lines of code for exercise editor (default to size of code chunk).</td>
 </tr>
-<tr class="even">
+<tr class="odd">
 <td><code>exercise.timelimit</code></td>
 <td>Number of seconds to limit execution time to (defaults to 30).</td>
 </tr>
-<tr class="odd">
+<tr class="even">
 <td><code>exercise.checker</code></td>
 <td>Function used to check exercise answers (e.g., <code>gradethis::grade_learnr()</code>).</td>
 </tr>
@@ -304,6 +308,10 @@ See the table below for a full description of all the arguments supplied to `exe
 <td>The last value of the evaluated chunk.</td>
 </tr>
 <tr class="odd">
+<td><code>engine</code></td>
+<td>The <code>engine</code> value of the evaluated chunk.</td>
+</tr>
+<tr class="even">
 <td><code>...</code></td>
 <td>Unused (include for compatibility with parameters to be added in the future)</td>
 </tr>
@@ -315,7 +323,7 @@ See the table below for a full description of all the arguments supplied to `exe
 
 ## Exercise Caption
 
-By default exercises are displayed with caption of "Code". However, in some cases you may want either a custom per-chunk caption or a generic caption with a different connodation (e.g. "Exercise" or "Sandbox"). For example:
+By default exercises are displayed with caption of "Code". However, in some cases you may want either a custom per-chunk caption or a generic caption with a different connotation (e.g. "Exercise" or "Sandbox"). For example:
 
 <div id="exercisecaption"></div>
 <script type="text/javascript">loadSnippet('exercisecaption')</script>

inst/lib/tutorial/tutorial.css

@@ -117,3 +117,8 @@
   height: 100%;
   border: solid 1px #cccccc;
 }
+
+.tutorial-exercise-engine {
+  color: #c0c0c0;
+  margin-right: 10px;
+}

inst/lib/tutorial/tutorial.js

@@ -851,6 +851,8 @@ Tutorial.prototype.$initializeExerciseEditors = function() {
     // capture label and caption
     var label = exercise.attr('data-label');
     var caption = exercise.attr('data-caption');
+    var engine_txt = exercise.attr('data-engine');
+
 
     // helper to create an id
     function create_id(suffix) {
@@ -895,7 +897,11 @@ Tutorial.prototype.$initializeExerciseEditors = function() {
 
     // creating heading
     var panel_heading = $('<div class="panel-heading tutorial-panel-heading"></div>');
-    panel_heading.text(caption);
+    // add engine if it exists
+    if (engine_txt && engine_txt.length > 0) {
+      panel_heading.append($('<span class="tutorial-exercise-engine"></span>').text(engine_txt));
+    }
+    panel_heading.append($('<span class="tutorial-exercise-caption"></span>').text(caption));
     input_div.append(panel_heading);
 
     // create body
@@ -966,6 +972,13 @@ Tutorial.prototype.$initializeExerciseEditors = function() {
     // get the engine
     var engine = chunk_options["engine"]
 
+    if (engine != "r") {
+      // disable ace editor diagnostics if a non-r langauge engine is set
+      diagnostics = null;
+      // disable auto-completion if a non-r language engine is set
+      completion = null;
+    }
+
     // set tutorial options/data
     editor.tutorial = {
       label: label,

inst/tutorials/polyglot/polyglot.Rmd

@@ -0,0 +1,56 @@
+---
+title: "Multi-language exercises"
+author: "Zoë Wilkinson Saldaña"
+output: learnr::tutorial
+runtime: shiny_prerendered
+---
+
+```{r setup, include = FALSE}
+library(learnr)
+
+# altered from https://datacarpentry.org/R-ecology-lesson/05-r-and-databases.html
+if (!file.exists("portal_mammals.sqlite")) {
+  download.file(url = "https://ndownloader.figshare.com/files/2292171",
+                destfile = "portal_mammals.sqlite", mode = "wb")
+}
+mammals <- DBI::dbConnect(RSQLite::SQLite(), "portal_mammals.sqlite")
+```
+
+### Python or R?
+
+The following two code exercises run language agnostic code.  It will finally evaluate to either 5 or 10.
+
+```{r r-not-python, exercise=TRUE, exercise.lines = 5}
+# if running in R, this should return 10
+# if running in Python, this should return FALSE and 5
+x = 5
+x <-10
+print(x)
+```
+
+```{python python-not-r, exercise=TRUE, exercise.lines = 5}
+# if running in R, this should return 10
+# if running in Python, this should return FALSE and 5
+x = 5
+x <-10
+print(x)
+```
+
+### Bash
+
+Execute exercises in bash
+
+```{bash bash-not-r, exercise = TRUE}
+echo "hello world"
+date
+```
+
+### SQL
+
+Use a SQL connection defined in a setup chunk.
+
+```{sql sql-not-r, exercise = TRUE, connection="mammals"}
+SELECT *
+FROM `surveys`
+LIMIT 10
+```

tests/testthat/test-available-tutorials.R

@@ -25,6 +25,7 @@ test_that("Tutorial names are retrieved", {
   - ex-data-summarise : \"Summarise Tables\"
   - ex-setup-r        : \"Set Up\"
   - hello             : \"Hello, Tutorial!\"
+  - polyglot          : \"Multi-language exercises\"
   - quiz_question     : \"Tutorial Quiz Questions in `learnr`\"
   - setup-chunks      : \"Chained setup chunks\"
   - slidy             : \"Slidly demo\""