Last updated: September 18, 2019
For security, compatibility and performance reasons, Pressbooks restricts the range of third-party plugins that are included on our hosted networks. Anyone interested in using a particular WordPress plugin with our hosted offering of Pressbooks is welcome to submit a plugin request. All requested plugins undergo a review process and are evaluated with reference to our plugins policy.
Please see below for a list of plugins evaluated to date and the results of the evaluation. We update this list on a quarterly basis (see the top of the document for a “last updated” date).
The following third-party plugins have been tested and approved for use on Pressbooks-hosted networks.
Note: Available plugins may differ based on service level. Some plugins listed below are part of the Pressbooks hosting stack and may not be administered by network managers.
- Akismet Anti-Spam*
- Parsedown Party
- Redis Cache
- Regenerate Thumbnails
- User Activation Keys
- WP Fail2Ban Redux
- WP QuickLaTeX
* Requires subscription.
Requested, need further development or investigation
- Enhanced Media Library
This plugin was requested by an open-source Pressbooks user. In response to this initial question, Pressbooks changed the way that it filters approved and disapproved taxonomies for users. The plugin notes some general compatibility risks. Because this plugin was not requested by a network manager on one of our hosted networks, we have not thoroughly tested this plugin for compatibility with our method for organizing uploaded files.
- Enable Media Replace
This plugin was requested by a PressbooksEDU client to help users replace images in the media gallery without downloading, renaming, and re-uploading files. The request is currently under investigation.
The list of disallowed plugins below is not a judgement on the quality or suitability of these plugins for various use cases. Plugins are generally disallowed because: they are incompatible with the Pressbooks application in a non-trivial way, they duplicate functionality that exists within the Pressbooks application, or they do not meet the performance requirements of our enterprise hosting service.
- Broken Link Checker
This plugin placed an unacceptable load on server resources when evaluated in 2017. Users who wish to check their networks/books for broken links may be interested in using the W3C’s link validator: https://validator.w3.org/checklink instead.
- CM Tooltip Glossary
As of Pressbooks 5.6.0, Pressbooks now includes a native glossary tool which includes most of the functionality provided by this plugin. See https://guide.pressbooks.com/chapter/glossaries/.
- OpenStax Import for Pressbooks
This plugin was closed in May 2019 and is no longer being maintained. Prior to the plugin being abandoned by its creators, the plugin required users to upload .zip files of the books in question, many of which are very large. The size of these files and the strain this process puts on server processes meant that we were unwilling to install the plugin on our production networks.
- Show/Hide Content
As of McLuhan 2.3.0, Pressbooks now includes a web theme option to allow users to collapse and expand sections delineated by top-level headings within the webbook. See https://guide.pressbooks.com/chapter/collapsible-subsections-for-webbook/.
- Simple Custom CSS
As of Pressbooks 4.3.0, users can enter custom CSS for web, ebook, or print stylesheets using the ‘Custom Styles’ tool. See https://guide.pressbooks.com/chapter/customizing-your-exports-with-custom-styles/.
- Simple Lightbox
As of McLuhan 2.4.0, Pressbooks includes a lightbox feature for linked images that can be activated in web theme options. See https://guide.pressbooks.com/chapter/enabling-and-using-lightboxes-for-images/.
- SSL Insecure Content Fixer
On our hosted networks, our Nginx configuration serves all our network content over HTTPS, so this plugin would only be needed for third-party content.