Setup gradethis for use within learnr

To use gradethis in your learnr tutorial, you only need to call library(gradethis) in your tutorial's setup chunk.

```{r setup}
library(learnr)
library(gradethis)
```

Use gradethis_setup() to change the default options suggested by gradethis. This function also describes in detail each of the global options available for customization in the gradethis package. Note that you most likely do not want to change the defaults values for the learnr tutorial options that are prefixed with exercise.. Each of the gradethis-specific arguments sets a global option with the same name, prefixed with gradethis.. For example, pass sets gradethis.pass.

Usage

gradethis_setup(
  pass = NULL,
  fail = NULL,
  ...,
  code_correct = NULL,
  code_incorrect = NULL,
  maybe_code_feedback = NULL,
  maybe_code_feedback.before = NULL,
  maybe_code_feedback.after = NULL,
  pass.praise = NULL,
  fail.hint = NULL,
  fail.encourage = NULL,
  pipe_warning = NULL,
  grading_problem.message = NULL,
  grading_problem.type = NULL,
  error_checker.message = NULL,
  allow_partial_matching = NULL,
  exercise.checker = gradethis_exercise_checker,
  exercise.timelimit = NULL,
  compare_timelimit = NULL,
  exercise.error.check.code = NULL,
  fail_code_feedback = NULL
)

Arguments

pass

Default message for pass(). Sets options("gradethis.pass")

fail

Default message for fail(). Sets options("gradethis.fail")

...

Arguments passed on to learnr::tutorial_options

exercise.cap: Caption for exercise chunk (defaults to the engine's icon or the combination of the engine and " code").
exercise.eval: Whether to pre-evaluate the exercise so the reader can see some default output (defaults to FALSE).
exercise.lines: Lines of code for exercise editor (defaults to the number of lines in the code chunk).
exercise.blanks: A regular expression to be used to identify blanks in submitted code that the user should fill in. If TRUE (default), blanks are three or more underscores in a row. If FALSE, blank checking is not performed.
exercise.completion: Use code completion in exercise editors.
exercise.diagnostics: Show diagnostics in exercise editors.
exercise.startover: Show "Start Over" button on exercise.
exercise.reveal_solution: Whether to reveal the exercise solution if a solution chunk is provided.

code_correct

Default correct message for grade_this_code(). If unset, grade_this_code() falls back to the value of the gradethis.pass option. Sets the gradethis.code_correct option.

code_incorrect

Default incorrect message for grade_this_code(). If unset grade_this_code() falls back to the value of the gradethis.fail option. Sets the gradethis.code_incorrect option.

maybe_code_feedback

Logical TRUE or FALSE to determine whether maybe_code_feedback() should return code feedback, where if FALSE, maybe_code_feedback() will return an empty string. maybe_code_feedback() is used in the default messages when pass() or fail() are called without any arguments, which are set by the pass or fail arguments of gradethis_setup().

maybe_code_feedback.before, maybe_code_feedback.after

Text that should be added before or after the maybe_code_feedback() output, if any is returned. Sets the default values of the before and after arguments of maybe_code_feedback().

pass.praise

Logical TRUE or FALSE to determine whether a praising phrase should be automatically prepended to any pass() or pass_if_equal() messages. Sets the gradethis.pass.praise option.

fail.hint

Logical TRUE or FALSE to determine whether an automated code feedback hint should be shown with a fail() or fail_if_equal() message. Sets the gradethis.fail.hint option.

fail.encourage

Logical TRUE or FALSE to determine whether an encouraging phrase should be automatically appended to any fail() or fail_if_equal() messages. Sets the gradethis.fail.encourage option.

pipe_warning

The default message used in pipe_warning(). Sets the gradethis.pipe_warning option.

grading_problem.message

The feedback message used when a grading error occurs. Sets the gradethis.grading_problem.message option.

grading_problem.type

The feedback type used when a grading error occurs. Must be one of "success", "info", "warning" (default), "error", or "custom". Sets the gradethis.grading_problem.type option.

error_checker.message

The default message used by gradethis's default error checker, gradethis_error_checker(). Sets the gradethis.error_checker.message option.

allow_partial_matching

Logical TRUE or FALSE to determine whether partial matching is allowed in grade_this_code(). Sets the gradethis.allow_partial_matching option.

exercise.checker

Function used to check exercise answers (e.g., gradethis::grade_learnr()).

exercise.timelimit

Number of seconds to limit execution time to (defaults to 30).

compare_timelimit

pass_if_equal() and fail_if_equal() call waldo::compare() internally. This helps ensure an accurate comparison, but sometimes takes a long time. compare_timelimit is the time limit in seconds for the execution of waldo::compare() (defaults to 80% of exercise.timelimit). If the time limit is exceeded, identical() is used instead of waldo::compare().

exercise.error.check.code

A string containing R code to use for checking code when an exercise evaluation error occurs (e.g., "gradethis::grade_code()").

fail_code_feedback

Deprecated. Use maybe_code_feedback.

Value

Invisibly returns the global options as they were prior to setting them with gradethis_setup().

Global package options

These global package options can be set by gradethis_setup() or by directly setting the global option. The default values set for each option when gradethis is loaded are shown below.

Option	Default Value
`gradethis.pass`	`"{gradethis::random_praise()} Correct!"`
`gradethis.pass.praise`	`FALSE`
`gradethis.fail`	`"Incorrect.{gradethis::maybe_code_feedback()} {gradethis::random_encouragement()}"`
`gradethis.fail.hint`	`FALSE`
`gradethis.fail.encourage`	`FALSE`
`gradethis.maybe_code_feedback`	`TRUE`
`gradethis.maybe_code_feedback.before`	`" "`
`gradethis.maybe_code_feedback.after`	`NULL`
`gradethis.code_correct`	`NULL`
`gradethis.code_incorrect`	`"{gradethis::pipe_warning()}{gradethis::code_feedback()} {gradethis::random_encouragement()}"`
`gradethis.pipe_warning`	"I see that you are using pipe operators (e.g. %>%), so I want to let you know that this is how I am interpreting your code before I check it:\n\n```r\n{.user_code_unpiped}\n```\n\n"
`gradethis.grading_problem.message`	`"A problem occurred with the grading code for this exercise."`
`gradethis.grading_problem.type`	`"warning"`
`gradethis.allow_partial_matching`	`NULL`
`gradethis.error_checker.message`	"An error occurred with your code:\n\n```\n{.error$message}\n```\n\n\n"
`gradethis.compare_timelimit`	`NULL`

Examples

# Not run in package documentation because this function changes global opts
if (FALSE) {
  old_opts <- gradethis_setup(
    pass = "Great work!",
    fail = "{random_encouragement()}"
  )
}

# Use getOption() to see the default value
getOption("gradethis.pass")
#> [1] "{gradethis::random_praise()} Correct!"
getOption("gradethis.maybe_code_feedback")
#> [1] TRUE

Usage

Arguments

Value

Global package options

See also

Examples