swirl 2.4.5

• Thank you @HenrikBengtsson for fixing a warning when
  warnPartialMatchArgs=TRUE. (#779)

• Fixed encoding test which was failing on CRAN (debian-clang-devel).

• Added "swirl_is_fun" option to swirl_options().

• Added Portuguese menu translations.

• Script questions behave more appropriately in RStudio. (#434, thank you @jimhester)

swirl 2.4.1

• Added new answer test: calculates_same_value().
• Now compatible with versions of testthat later than 0.11.0.

swirl 2.4.0

• Added support for multiple languages, including Spanish, French, German,
  Turkish, Simplified Chinese, and Korean. The default language can be changed
  using the function select_language().
• Added install_course() in order to install swirl courses that are
  distributed in the .swc format.
• The directories where swirl courses and where user data is stored can now be
  explicitly specified. These options can be set using the function
  swirl_options().
• It's now possible to log and collect a student's progression
  through a swirl course. Enable logging with swirl_options().
• Improved support for displaying non-ASCII character sets
  through UTF-8 encoding.
• Now compatible with swirlify::demo_lesson().

swirl 2.2.21

• Add mirror argument to install_from_swirl() to accommodate installing courses from the Bitbucket mirror of our swirl-courses GitHub repository. (Prompted by India's blocking of GitHub.)
• Check for existence of variable in swirl.R to address issue with using rm() command.

swirl 2.2.16

• Fix bug in install_from_swirl() that was causing install_from_swirl("R Programming") to install both R Programming and R Programming Alt.
• Fix troublesome links to the swirl_courses repo.

swirl 2.2.15

• Fix annoying typo in one of the "praise" messages.

swirl 2.2.14

• Add ?InstallCourses, which gives a brief overview of installing swirl courses and includes links to all relevant help files.
• Add email_admin() feature, which allows the user to automatically generate an email to be sent to [email protected]. The email includes space for a description of the problem along with the output from sessionInfo().
• Clean up swirl's core function, swirl() in swirl.R, so that we can view the administrative environment e with as.list(e) without complaint from R.
• Add empty cran-comments.md to appease new devtools release().

swirl 2.2.13

• Add a new script question type, which allows an instructor to present a preformatted R script to the user for editing and submission. swirl was originally designed for interactive programming at the prompt. It now accommodates multiline input, which allows for exploration of topics like writing functions and control structures, as well as more extended function calls.
• Allow user to make swirl feedback less playful with options(swirl_is_fun = FALSE).

swirl 2.2.12

• In welcome.default(), make sure the user doesn't put any special characters (using the [[:punct:]] regex) in his or her name, as this might lead to an invalid file path for their user data. Thanks to @Sarpwus for bringing this to my attention.
• Trim leading/trailing whitespace when reading lesson dependencies from dependson.txt.
• Add dev argument to install_from_swirl() to allow installation of courses in development from the swirl_misc repository.
• Update phrases.R to include new praise and 'try again' phrases. Thanks to @sagevann for the suggestions.
• Use capture.output() to avoid double printing due to second evaluation by safeEval() when AUTO_DETECT_NEWVAR is TRUE.

swirl 2.2.11

• Add testit() to functions for callback to ignore, so that swirl plays nicely with swirlify.
• Add from/to feature for testing specific units of content during course authoring.

swirl 2.2.10

• Corrected order of mergeList arguments in swirl.R.

swirl 2.2.9

• Add Regression Models to recommended courses.

swirl 2.2.8

• Alternate user progress tracking strategy without previous lag or freeze problems. Backwards compatible with existing course content. Tracks large or small lesson data sets by default, but these may be excluded by sourcing with local=FALSE from the initLesson.R file.
• Make course installation success/failure messages more robust.
• Add documentation for ?AnswerTests.
• Create a file for manual submission to Coursera immediately after the user enters his or her credentials. This way, no matter what happens during the submission process, manual submission is still an option. The file is deleted if automatic submission succeeds.
• Add any_of_exprs() to library of answer tests.

swirl 2.2.7

• Another check that Coursera challenge url is valid

• Fix bug related to user entering their Coursera Course ID with quotes.
• Fix bug causing swirl to fail when exiting from course menu.

swirl 2.2.5

• Add packageStartupMessage() that detects a cluttered workspace and warns the user that this may cause swirl to run slowly.
• Add main() function, which allows user to return to the main menu while a lesson is in progress.
• Add which_course argument to install_course_zip() that will facilitate manual installation. In particular, if a student downloads a zip file from the swirl courses repo, it comes with all courses in it. This function will allow the user to install only those that she wants.

swirl 2.2.4

• Bug fix related to skip() count not reseting upon lesson completion.

swirl 2.2.3

• Add confirmation step to Coursera submission process.
• Stash Course ID along with other Coursera creds.
• Display correct answer when user skip()s a question.

swirl 2.2.2

• Fix bug in old answer test caused by upgrade to R 3.1.0 and made evident in the Data Analysis course.

swirl 2.2.1

• Check for missing entries in content YAML to prevent failure when loading a course.

• Instructional content is no longer shipped with swirl. Instead, it is located in our course repo. When the user starts swirl, he or she is given the option to install the R Programming course automatically or be taken to the course repo page. Courses can also be installed with the install_from_swirl() function.
• Content authoring tools have also been removed from the swirl package. We've created a new package called swirlify, which is a comprehensive toolbox for swirl instructors. Instructions for authoring content are on the Instructors page of the swirl website.
• Package dependencies for a lesson are now managing by including a file called dependson.txt in the lesson directory, which lists required packages one line at a time. This strategy is mainly for backwards compatibility and will take a different form for new content in future releases. When the user begins a lesson with package dependencies, swirl attempts to load each package in turn and prompts the user to automatically install any packages not found.
• Added help files for answer tests contained in answerTests.R.
• Added progress bar feature using utils::txtProgressBar().
• Added test mode for compatibility with the swirlify package.
• Integrated with Coursera API to allow enrolled students to receive credit for swirl lessons associated their Coursera course.
• rmd2df() can finally handle figure and video units of instruction.

v2.1.1

• Fixed a bug in the third lesson of Intro to R.

v2.1.0

• parse_content() now parses content (at runtime) in its original form (R Markdown, YAML, etc.), making conversion to CSV files unnecessary. The appropriate parsing method is called based on the extension of the lesson file. Creating a new course authoring format is as simple as writing a new method for parse_content() that accepts the content as input and returns a properly structured lesson object.
• author_lesson() function creates and opens a customized lesson template for authoring content.
• Suite of functions for installing (and uninstalling) swirl courses:
  • install_course_directory(): Install a course from a course directory
  • install_course_dropbox(): Install a course from a zipped course directory shared on Dropbox
  • install_course_github(): Install a course from a GitHub repository
  • install_course_google_drive(): Install a course from a zipped course directory shared on Google Drive
  • install_course_url(): Install a course from a url that points to a zip file
  • install_course_zip(): Install a course from a zipped course folder
  • uninstall_course(): Uninstall a course
  • zip_course(): Zip a course directory
• Course authors can add custom tests for student repsonses.
  • Custom tests may be defined in the lesson directory in file named customTests.R.
  • Custom tests run in the same environment as tests provided with the package.
• Revised suite of answer tests (contained in answerTests2.R) using a more natural function call syntax.
• Revised user progress tracking and restoration.
  • Improved tracking by taking environmental "snapshots."
  • Keep a list of variables created or modified by correct responses.
  • Restore list to global environment after a lesson is suspended and resumed.
• Message notifying the user when she's completed a lesson, just prior to returning to the main menu.
• Miscellaneous big fixes

• Fixed bug related to package dependencies (via imports)

• Uses addTaskCallback() as a mechanism to capture user input directly from the R prompt.
• During instruction, info() brings up a menu of options including bye(), skip(), play(), and nxt().
• skip() allows the user to skip the current question. swirl automatically evaluates the correct answer in the user's workspace in case future questions depend on the result.
• Includes a library of answer tests based on testthat, an R package designed by Hadley Wickham for unit testing.
• Tests user responses for correctness based various combinations of the aforementioned answer tests. A user is judged to have answered a question correctly when the answer tests specified for that question are satisfied.
• The answer tests operate on the R expression entered by the user, as opposed to the string representation of it (see swirl 1.0). This avoids marking a user incorrect for stylistic discrepancies such as including single spaces between function arguments, etc.
• Makes heavy use of R's S3 object oriented programming dialect to promote an easily extensible architecture. Incorporating new functionality simply requires writing new methods for existing "core" functions.
• Instructors can now author content in an R Markdown (.Rmd) file, then use rmd2csv() to create the CSV file from which swirl reads content. This is an experimental feature based on syntax employed by slidify, an R package designed by Ramnath Vaidyanathan for creating interactive web presentations.