SCF Polylang i18n

SCF Polylang i18n is a WordPress plugin that complements custom post types and taxonomies registered with Secure Custom Fields.

It translates labels and descriptions through Polylang, exposes managed objects in Polylang settings, and adds project-specific rewrite rules for translated CPT and taxonomy URL bases.

Scope

This plugin does not register custom post types or taxonomies. Secure Custom Fields remains the source of truth for object registration.

The plugin currently provides:

• Polylang string registration for custom post type and taxonomy labels and descriptions
• Runtime translation of registered labels and descriptions
• Translated rewrite bases for managed custom post type archives, singles, and taxonomies
• URL generation filters that keep WordPress links aligned with translated bases
• Optional SiteSEO placeholder support for %%cpt_description%% and %%post_type_description%%
• Automatic cleanup of plugin options on uninstall

The plugin does not provide:

• Automatic content translation
• Taxonomy term translation
• Polylang Pro translated slug UI
• Full replacement of all internal SiteSEO placeholders

Requirements

• WordPress 6.5 or later
• PHP 8.0 or later
• Polylang
• Secure Custom Fields

SiteSEO integration is optional and only runs when the SiteSEO plugin is active.

Repository layout

• scf-polylang-i18n.php Plugin bootstrap and metadata
• src/ Runtime classes
• config/mappings.php Optional file-based default mappings
• languages/ Translation template files
• bin/ Repository smoke test and release packaging helpers
• .github/ Issue templates and GitHub Actions workflows

Development

Install development dependencies:

composer install

Run coding standards:

composer lint

Run repository checks:

php bin/smoke-test.php

Run the runtime smoke test against a local WordPress install:

php bin/smoke-test.php /absolute/path/to/wordpress

Build a release ZIP from the current commit:

bin/build-plugin-zip.sh

The ZIP is created with git archive --worktree-attributes, so repository-only files listed in .gitattributes stay out of the distributable plugin.

Local WordPress usage

The main settings screen is available at:

Settings > SCF Polylang i18n

From there you can manage:

• language columns used for slugs
• managed custom post types and taxonomies
• per-language rewrite bases
• archive and single rewrite behavior for custom post types
• label and description registration with Polylang
• whether the default language should remain unprefixed

Saved settings are stored in the scf_polylang_i18n_mappings option. After the first admin save, that option becomes the primary editable mapping source.

File-based defaults

You can define defaults in config/mappings.php. The admin UI overrides matching values after the option is saved.

Example:

return [
    'languages' => ['pt', 'en'],
    'post_types' => [
        'solution' => [
            'slugs' => [
                'pt' => 'solucoes',
                'en' => 'solutions',
            ],
            'archive' => true,
            'single' => true,
        ],
    ],
    'taxonomies' => [
        'solution_category' => [
            'slugs' => [
                'pt' => 'categorias-de-solucoes',
                'en' => 'solution-categories',
            ],
        ],
    ],
    'auto_labels' => true,
    'unprefixed_default_language' => false,
];

With unprefixed_default_language => false, generated URLs include a language prefix for every configured language, for example:

/pt/solucoes/
/pt/solucoes/nome-do-post/
/pt/categorias-de-solucoes/nome-do-termo/

Release workflow

The repository includes:

• CI Runs Composer validation, PHPCS, the repository smoke test, build packaging, and Plugin Check against the packaged plugin
• Release Plugin ZIP Builds scf-polylang-i18n.zip and attaches it to GitHub releases

SiteSEO placeholders

For CPT archives and singles, the plugin adds these placeholders to SiteSEO templates:

%%cpt_description%%
%%post_type_description%%

They can be used in SiteSEO title and meta description templates for managed custom post types.