exercises.Rmd

---
title: "Web Exercises"
output: webex::webex_default
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(echo = TRUE)
if (!requireNamespace("webex")) {
  stop("You must have the 'webex' package installed to knit HTML from this template.\n   devtools::install_github(\"psyteachr/webex\")")
} else {
  library("webex")
}
```

This is a Web Exercise template created by the [psychology teaching team at the University of Glasgow](http://www.psy.gla.ac.uk), based on ideas from [Software Carpentry](https://software-carpentry.org/lessons/). This template shows how instructors can easily create interactive web documents that students can use in self-guided learning.

The webex package provides a number of functions that you use in [inline R code](https://github.com/rstudio/cheatsheets/raw/master/rmarkdown-2.0.pdf) to create HTML widgets (text boxes, pull down menus, buttons that reveal hidden content). Examples are given below. Knit this file to HTML to see how it works.

**NOTE: To use the widgets in the compiled HTML file, you need to have a JavaScript-enabled browser.**

## Total Correct (`total_correct()`)

The function `total_correct()` displays a running total of correct responses. Change the `elem` argument to display in a different style (e.g., `h2` or `h3` for header styles). If you're comfortable with css styles or classes, you can add them with the `args` argument. 

`r total_correct(elem = "h3", args = "style='color:#003366;'")`

## Fill-In-The-Blanks (`fitb()`)

Create fill-in-the-blank questions using `fitb()`, providing the answer as the first argument.

- 2 + 2 is `r fitb("4")`

You can also create these questions dynamically, using variables from your R session.

```{r echo = FALSE}
x <- sample(2:8, 1)
```

- The square root of `r x^2` is: `r fitb(x)`

The blanks are case-sensitive; if you don't care about case, use the argument `ignore_case = TRUE`.

- What is the letter after D? `r fitb("E", ignore_case = TRUE)`

If you want to ignore differences in whitespace use, use the argument `ignore_ws = TRUE` (which is the default) and include spaces in your answer anywhere they could be acceptable.

- How do you load the tidyverse package? `r fitb(c("library( tidyverse )", "library( \"tidyverse\" )", "library( 'tidyverse' )"), ignore_ws = TRUE, width = "20")`

You can set more than one possible correct answer by setting the answers as a vector.

- Type a vowel: `r fitb(c("A", "E", "I", "O" , "U"), ignore_case = TRUE)`

You can use regular expressions to test answers against more complex rules.

- Type any 3 letters: `r fitb("^[a-zA-Z]{3}$", width = 3, regex = TRUE)`

## Multiple Choice (`mcq()`)

- "Never gonna give you up, never gonna: `r mcq(c("let you go", "turn you down", "run away", answer = "let you down"))`"
- "I `r mcq(c(answer = "bless the rains", "guess it rains", "sense the rain"))` down in Africa" -Toto

## True or False (`torf()`)

- True or False? You can permute values in a vector using `sample()`. `r torf(TRUE)`

## Hidden solutions and hints

You can fence off a solution area that will be hidden behind a button using `hide()` before the solution and `unhide()` after, each as inline R code.  Pass the text you want to appear on the button to the `hide()` function.

If the solution is an RMarkdown code chunk, instead of using `hide()` and `unhide()`, simply set the `webex.hide` chunk option to TRUE, or set it to the string you wish to display on the button.

### Example problem

**Recreate the scatterplot below, using the built-in `cars` dataset.**

```{r echo = FALSE}
with(cars, plot(speed, dist))
```


`r hide("I need a hint")`

See the documentation for `plot()` (`?plot`)

`r unhide()`


<!-- note: you could also just set webex.hide to TRUE -->

```{r eval = FALSE, webex.hide="Click here to see the solution"}
plot(cars$speed, cars$dist)
```

<!-- TO CHANGE WIDGET COLOURS:
  move command below out of this HTML comment area
  and then re-compile;
  unfilled becomes yellow, correct becomes pink 
     
`r style_widgets("#FFFF00", "#FF3399")`
-->