Release notes for WeBWorK 2.16

This article is under construction. Use the information herein with caution until this message is removed.

New WeBWorK Features

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 (need a link to POD)
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

TikZ images in problems.
New macro parserGraphTool.pl for interactive graphing problems (link to POD and documentation)
"digits" tolType (needs explanation wherever tolerance in general is explained)
`random_prime` and `random_pairwise_coprime` macros. (link to POD)
PGML can be used in set header files
MathObject: context classes can have aliases and alternates. (For example variable "X" could be an alias for "x".)
Improved hardcopy of PGML problems
Improvements in efficiency to PGstatisticsmacros.pl

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

Many third party javascript libraries (jquery, jquery-ui, mathjax, codemirror, etc.) are no longer packaged with WeBWorK. These libraries are now installed via npm:

Install npm from your package manager (Ubuntu: apt install npm CentOS/RHEL: yum install npm).
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)
- Archive::Zip (on Ubuntu install the package libarchive-zip-perl)
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 math4 theme has changed. If you use a custom theme, you may need to update your theme files to address these changes.
WeBWorK is currently not compatible with recent versions of the SQL::Abstract package, so avoid upgrading past version 1.8. WW is known to work with versions up to 1.87.
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" />

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

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)

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