An Update on Preferred Languages

5 years after announcing the Preferred Languages feature project and implementing the first prototype, it’s time for a long overdue update on where things currently stand.

More than half of all WordPress sites in the world use a language other than US English. For these sites and users, the options to change the site and user language are great. But when there’s no translationtranslation The process (or result) of changing text, words, and display formatting to support another language. Also see localization, internationalization. for a given pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the WordPress.org Plugin Directory https://wordpress.org/plugins/ or can be cost-based plugin from a third-party or theme, WordPress falls back to US English. That’s a poor user experience for many non-English speakers.

The Preferred Languages plugin solves this issue by doing the same thing operating systems, browsers, and other types of software have been doing for years. It lets you select multiple preferred languages in your settings. WordPress then tries to load the translations for the first language that’s available, falling back to the next language in your list.

Recent New Features

After stabilizing the initial prototype, the feature pluginFeature Plugin A plugin that was created with the intention of eventually being proposed for inclusion in WordPress Core. See Features as Plugins. has lived a mostly dormant life, with only irregular updates here and there. Adding support for JavaScript i18n introduced in WordPress 5.0 was the biggest enhancementenhancement Enhancements are simple improvements to WordPress, such as the addition of a hook, a new feature, or an improvement to an existing feature.. With the plugin being stable and used on thousands of sites without issues, there was simply no need for any other change. Yet, the plugin was far from feature complete.

Over the past year, I blew the dust off and made significant improvements to the plugin:

• Bringing UI and code up-to-date with latest WordPress version
• Improved Multisitemultisite Used to describe a WordPress installation with a network of multiple blogs, grouped by sites. This installation type has shared users tables, and creates separate database tables for each blog (wp_posts becomes wp_0_posts). See also network, blog, site support, bringing Preferred Languages to Networknetwork (versus site, blog) settings
• Site Health integration
• Increased test coverage
• Improved compatibility with other plugins, especially those accessing the locale user metaMeta Meta is a term that refers to the inside workings of a group. For us, this is the team that works on internal WordPress sites like WordCamp Central and Make WordPress.
• Added an option to merge incomplete translations to avoid fallbacks to US English

The latter is actually a pretty cool enhancement and can be enabled using a filterFilter Filters are one of the two types of Hooks https://codex.wordpress.org/Plugin_API/Hooks. They provide a way for functions to modify data of other functions. They are the counterpart to Actions. Unlike Actions, filters are meant to work in an isolated manner, and should never have side effects such as affecting global variables and output.. Here’s what it does:

Let’s say your preferred languages are es_CR, es_MX, es_ES, en_US (in this order). With this feature, if some of the translations are incomplete, your site will be displayed in es_CR, with missing strings taken from es_MX, es_ES etc. Without this feature, missing strings would simply be displayed in US English straight away. Merging translations this way makes for a much better user experience.

What’s Still Missing / Open Questions

Textdomain Registry

Since the Preferred Languages feature plugin also needs to work well when switching locales, #39210 has been a missing feature for a long time. While the plugin has its own implementation of a textdomain registry originally created (but then reverted) in that ticketticket Created for both bug reports and feature development on the bug tracker., it is required for this change to finally land in coreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress..

My hope is that this can be implemented in WordPress 6.1+.

JavaScriptJavaScript JavaScript or JS is an object-oriented computer programming language commonly used to create interactive effects within web browsers. WordPress makes extensive use of JS for a better user experience. While PHP is executed on the server, JS executes within a user’s browser. https://www.javascript.com/. Code Base

The initial version of the Preferred Languages plugin was built in a pre-GutenbergGutenberg The Gutenberg project is the new Editor Interface for WordPress. The editor improves the process and experience of creating new content, making writing rich content much simpler. It uses ‘blocks’ to add richness rather than shortcodes, custom HTML etc. https://wordpress.org/gutenberg/ era, using jQuery and jQuery UI Sortable. It doesn’t make much sense to potentially merge such a new UI component into core that is built with those technologies.

Rather, some time should be spent to rebuild the client-side code. There are two possible options here:

1. Rewrite in vanilla JavaScript, replacing jQuery with modern Web APIs. This is most feasible when removing the capability to sort languages using drag & drop, for which jQuery UI Sortable is currently used.
   
   If we’re okay with dropping drag & drop functionality, then this would be a straightforward change.
2. Rewrite everything in ReactReact React is a JavaScript library that makes it easy to reason about, construct, and maintain stateless and stateful user interfaces. https://reactjs.org/.. A prototype of this actually exists, so it’s mostly a matter of finishing it up & perhaps submitting some upstream PRs to Gutenberg for any missing features.
   Using React would be more in line with current best practices and expansion of Gutenberg throughout WordPress adminadmin (and super admin). Such a rewrite would also facilitate potential use of the component directly within a Gutenberg context.
   On the other hand, it would significantly increase overall code size and thus maintenance burden, for little immediate benefit.

While I am currently heavily leaning towards the first option, inputs are always welcome!

Of course, if we are okay with keeping jQuery & jQuery UI Sortable, then no change is needed at all.

The Next Steps

The Preferred Languages feature plugin can always use help with development and testing. Right now resolving the two open questions is the main priority before proposing merging this functionality into core.

Active development is taking place on GitHub. If you want to get involved, check out open issues and join the #core-i18n channel on Slack.

#feature-plugins, #feature-projects, #i18n, #polyglots, #preferred-languages