# Release notes for WeBWorK 2.16

## New WeBWorK Features

• A new manual problem grader that works for all problems in homework and in gateway quizzes.
• The ability to navigate between students when acting as a student
• A confirmation dialog appears when a student clicks on a timed gateway quiz
• Upgrades to the way images are shown to students (resize, zoom, drag)
• Upgraded to MathJax 3 from MathJax 2
• As of 2.15 WeBWorK supports MathQuill for student input.
• ADD_JS_FILE and ADD_CSS_FILE in the PG.pl macro.
• Explanation essays (ask for a regular answer, separately ask for an explanation essay, but the essay part can be globally disabled)
• Rearrange presentation order for homework and quizzes on Homework Sets page (see PR #1282)
• Achievements items need not be single-use
• Major cleanup was done to defaults.config and localOverrides.conf.
• Revised / finer permission settings for the WebworkWebservice (see PR #1163)
• Course level control of support for PG to allow Unicode alternative math symbols etc. (see PR #1174)
• Support for including percentage grades per assignment in CSV output (see PR #1085 and PR #1131 which added a checkbox to include the new data or not). The code depends on the assumption that the total number of points available on an assignment in a constant.
• Passwords are consistently trimmed from leading and trailing white-space, to prevent users from being able to set passwords which could not be used to log in. (see PR #1290)
• Additional improvements and changes can be found on GitHub, and many will appear in the WW 2.16 release planning and testing project board.

## New PG Features

• Revised "WeBWorK errors" handling options. Option to hide detailed error messages from users but to store them in the error.log file.
• new settings: MIN_HTML_ERRORS JSON_ERROR_LOG
• see PR #1190
• Same-site Cookie support: (see PR #1269, the changed to default to Lax in PR #1307 and the discussion in the older PR #1149.)
• Fix applets in gateway quizzes
• Support for the DBD::MariaDB driver in addition to the DBD::mysql driver. This alternate driver supports both mySQL and MariaDB databases, and is consider to have better UTF-8 support. Using it also seemed to reduce certain types of connection errors.
• Improvements to LTI integration, and improved debugging
• LMS name and URL in message about needing to access an assignment via the LTI link in the LMS (before the grade passback setting data is available for the user) is now configurable. (see PR #1280 and PR #1285)
• Improved grade passback code, with better debugging features. (see PR #1177)
• The two round process (only update the LMS if the grade changed by at least 0.1 point from 100) is turned on by setting \$lti_check_prior = 1; in course.conf (or site wide in conf/authen_LTI.conf).
• A different nonce generation method is used, which may reduce cases of error if a nonce is reused while the LMS still considers it to be recently used.
• However, many of the problems reported as "duplicate nonce" in the forums seems to have been caused by system time being inaccurate on one of the sides.
• Revised WW side nonce handling, and error reporting (see PR #1199)

## Things that were fixed

Should there be a section like this? For example:

• Fixed bug when Gateway questions were not in sequential order
• Fix bug where, for example, Formula("-5/(-2 x)") would display 5/2x for its text string
• Fix bug with named answer usage. (See Named Answer Rules for the correct way to used named answers so that a problem will work in gateway quizzes. Note that all OPL problems that use named answers are broken for gateway quizzes because they don't do it this way.)
• Fixed bug in MultiAnswer objects with singleResult=>1 which did not properly compute score when setMessage is used. (see PR #524)
• Changes to color support for MathJax 3 controlled equations: PR#1294

• If you are upgrading from version 2.14 or earlier, you will want to convert your database to use the utf8mb4 character set. You can either follow the instructions at Converting the webwork database from the latin1 to the utf8mb4 character set, or try the upgrade script at /opt/webwork/webwork2/bin/upgrade-database-to-utf8mb4.pl. You should back up your database before trying either of these methods.
• Many third party javascript libraries (jquery, jquery-ui, mathjax, codemirror, etc.) are no longer packaged with WeBWorK. These libraries are now installed via npm:
1. Install npm from your package manager (Ubuntu: apt install npm CentOS/RHEL: yum install npm).
2. Use npm to install third party javascript:
  > cd /opt/webwork/webwork2/htdocs
> npm install

• WW 2.16 requires MathJax v3. Previous versions of WW required MathJax v2 that was installed at /opt/webwork/MathJax. WW 2.16 installs MathJax via npm, so if you are upgrading an existing WW installation you may safely delete /opt/webwork/MathJax.
• The following perl packages will need to be installed
• HTTP::Async (on Ubuntu install the package libhttp-async-perl)
• CGI::Cookie (see https://github.com/openwebwork/webwork2/pull/1149) (on Ubuntu 20.04 install the package libcgi-pm-perl; on earlier Ubuntu releases or RHEL/CentOS install from cpan)
• Archive::Zip (on Ubuntu install the package libarchive-zip-perl; on RHEL/CentOS install the package perl-Archive-Zip)
• There have been some tweaks to localOverrides.conf.dist. If you have not done any customization to localOverrides.conf then you should consider replacing it with a new copy of localOverrides.conf.dist. If you have made customizations in localOverrides.conf, you should consider synchronizing them with the latest version of localOverrides.conf.dist.
• The database configuration in site.conf has been refactored. To prevent compatibility issues in the future you should synchronize with the new version of site.conf.dist.
• WeBWorK is migrating to the perl DBD::MariaDB driver for interaction with the database, as some issues have been identified with DBD::mysql and recent versions of MariaDB. It is recommended that you install DBD::MariaDB (ubuntu package: libdbd-mariadb-perl; RHEL/CentOS installation via cpan requires the package mariadb-devel to be installed). Once it is installed it should be enabled in site.conf.
• Update your modelcourse with the new modelcourse.dist
• The math4 theme has changed. If you use a custom theme, you may need to update your theme files to address these changes.
• WeBWorK currently has conflicts with versions of the SQL::Abstract package newer than 1.87. The Ubuntu package manager currently provides version 1.86, so this is likely not a problem if you used apt to install. If you install SQL::Abstract from CPAN, you will likely get errors. WeBWorK 2.16 has added support for SQL::Abstract::Classic as an alternative. If you are installing from CPAN (e.g. RHEL/CentOS users), then you should install SQL::Abstract::Classic.
• If you want to allow the use of the new PGtikz.pl macro, you will need to install imagemagick (Ubuntu: apt install imagemagick) and modify /etc/ImageMagick-6/policy.xml and change the line near the end of the file from
  <policy domain="coder" rights="none" pattern="PDF" />


to

  <policy domain="coder" rights="read" pattern="PDF" />

• TikZ has two different options for a back-end program for generating images. The system administrator will have to decide which one is appropriate for their system (see https://github.com/openwebwork/webwork2/pull/1320)
• TikZ requires the following two commands to be installed on your system: dvisvgm and pdf2svg (Ubuntu: apt install dvisvgm pdf2svg; RHEL/CentOS: yum install dvisvgm - pdf2svg is not currently packaged for RHEL/CentOS.)
• UTF-8 support of the XML subsystem needs a local patch to be applied to /usr/share/perl5/XMLRPC/Lite.pm See: https://github.com/openwebwork/webwork2/issues/967#issuecomment-523941959. This patch can be applied with
 sudo patch -p1 -d / < /opt/webwork/webwork2/docker-config/xmlrpc-lite-utf8-fix.patch


## Call for Translators

Some text has changed in the WeBWorK interface, so there are new entries that need to be translated into other languages.