MLP Multilingual

MLP Multilingual is a WordPress plugin for running one site in several languages. It's for site owners and developers who want to translate posts, pages and terms, route each language under its own URL, and offer visitors a language switcher — without a translation-job workflow, machine translation, or a WooCommerce dependency they don't need.

Content stays entirely under the site owner's control: every translation is written by a person with the right WordPress capability, the same way any other post is edited.

Features

• Content translation for posts, pages and any taxonomy, linked into translation groups.
• Four URL strategies: a language directory (/fr/), a subdomain (fr.example.com), a separate domain per language, or a ?lang= query parameter.
• A language switcher available as a block, a [mlp_language_switcher] shortcode, and a widget.
• Reciprocal hreflang annotations (including x-default) on translated posts and pages.
• Full bidirectional RTL support, including a block editor canvas that flips to match the post's own language while the admin chrome stays in the site's admin language.
• Admin screens for Languages, Settings, Tools and Strings.
• REST API support: language fields on post responses, and a lang collection parameter for filtering requests by language.
• Compatibility functions for themes and plugins written against Polylang or WPML (activation is refused while either is actually active — see the user guide).
• String translation for gettext strings and for literal text labels baked into block markup, from a dedicated admin screen.

It deliberately does not do translation-job management, machine translation, WooCommerce integration, or WordPress multisite/network installs. See the user guide's first section for the full list of what it does and doesn't cover.

Requirements

• WordPress 6.4 or newer.
• PHP 8.1 or newer.
• Polylang and WPML must not be active at the same time as this plugin.

Installation

From a zip

1. Upload the plugin's zip through the WordPress admin's Plugins → Add New → Upload Plugin, or extract it into wp-content/plugins/ on the server.
2. Activate it from the Plugins screen. Activation is refused (with an explanation) if Polylang or WPML is currently active — deactivate whichever one you are replacing first.
3. Continue with the user guide's quick start to add your first languages.

This plugin is not (yet) listed on WordPress.org (see Project status below); build the zip yourself with bin/build-zip from a checkout of this repository — see Development below.

For development

1. Clone this repository.
2. Install the containerised toolchain's prerequisites: Docker and Node. No local PHP, Composer, or WP-CLI install is required — see Development below for how those run instead.
3. bin/composer install to install PHP dependencies.
4. npx wp-env start to bring up a local WordPress instance at http://localhost:8888, with this checkout mounted as the mlp-multilingual plugin (see .wp-env.json).
5. bin/seed-e2e if you want the same demo content (languages, a /language-demo/ page, and a translated post pair) the e2e suite reads.

Documentation

The user guide is written for the person running the site — everything from installation to the exact wording you'll see when something goes wrong, with no assumed knowledge of how the plugin is built.

Contributing code or documentation instead? See CONTRIBUTING.md.

Licence

GPL-2.0-or-later. See LICENSE for the full text.

Project status

Version 0.1.0 — pre-release. The plugin is feature-complete against its own design spec and its test suite is green (unit, integration and end-to-end tiers; see Development below), but it is not yet listed on WordPress.org, and its plugin header, LICENSE and readme.txt still carry a handful of TODO: placeholders (author name and URLs, WordPress.org contributor usernames) that only the maintainer publishing it can fill in. Single-site only; no WordPress Multisite/network support is planned.

Development

There is no PHP, Composer, or WP-CLI on the development host -- only Docker and Node. PHP tooling therefore runs inside containers, and Node tooling runs through the locally installed Node (npx), both hidden behind bin/ wrappers so none of the commands below need a local PHP install:

All of the above must pass before a change is considered done. See CONTRIBUTING.md for the full contributor workflow and the standards enforced on top of these tools.