Parameterized xweave, an idea

swisscapital-param.Rmd

```{r eval=is.null(params), echo=FALSE}
n <- 5
```


```{r, include=FALSE}
alternatives <- tibble::tribble(
  ~answer, ~correct, ~solution,
  # 1
  "Zurich is the capital of Switzerland.", FALSE,
  "False. There is no de jure capital but the de facto capital of Switzerland is Bern.",
  # 2
  "Italian is an official language in Switzerland.", TRUE,
  "True. The official languages are: German, French, Italian, Romansh.",
  # 3
  "The currency in Switzerland is the Euro.", FALSE,
  "False. The currency is the Swiss Franc (CHF).",
  # 4
  "Switzerland is part of the European Union (EU).", FALSE,
  "False. Switzerland is part of the Schengen Area but not the EU.",
  # 5
  "The Swiss national holiday is August 1.", TRUE,
  "True. The establishment of the Swiss Confederation is traditionally dated to August 1, 1291."
)

choice <- sample(seq_len(nrow(alternatives)), n)
```


Question
========
Which of the following statements about Switzerland is correct?

```{r, results='asis', echo=FALSE}
answerlist(alternatives$answer[choice], markup = 'markdown')
```

Solution
========

```{r, results='asis', echo=FALSE}
answerlist(alternatives$solution[choice], markup = 'markdown')
```


Meta-information
================
exname: About Switzerland
extype: mchoice
exsolution: `r mchoice2string(alternatives$correct[choice])`
exshuffle: TRUE

weave.R

# pass parameters as a list

weave <- function(file, params = NULL) {
  envir <- if (!is.null(params)) list2env(params) else new.env()
  knitr::knit(file, envir=envir)
}