Multilingual Forms for Fluent Forms with Polylang

Translate Fluent Forms using Polylang — field labels, validation messages, confirmation messages, and notification emails — all from Polylang's Strings translations page.

Requirements

• WordPress 6.0+
• PHP 7.4+ (tested up to 8.3)
• Fluent Forms (free) — required
• Polylang or Polylang Pro — required (needs pll_register_string / pll__)

The plugin gates its own boot on both dependencies and emits an admin notice with an install/activate link if either is missing.

Installation

1. Install and activate Fluent Forms and Polylang (or Polylang Pro).
2. Clone this repo or upload the multilingual-forms-fluent-forms-polylang folder to wp-content/plugins/.
3. Activate Multilingual Forms for Fluent Forms with Polylang from the Plugins screen.

Usage

1. Edit a form → Settings → Polylang Translations → enable the toggle and save.
2. Open Languages → Strings translations in WP admin. Per-form strings appear under Fluent Forms <Form Title>, global FF settings under Fluent Forms Global Settings.
3. Translate the strings. The form renders in the visitor's current Polylang language; notifications and confirmations are sent in the language the submission was made in.

To stop translating a form, hit Reset Polylang Translation on the same tab.

Project layout

multilingual-forms-for-fluent-forms-with-polylang.php  # bootstrap, dependency gating, admin notices
src/
  Controllers/
    SettingsController.php             # wires up the per-form controllers
    FormSettingsController.php         # form settings tab + AJAX + asset injection
    GlobalSettingsController.php       # global FF option translation
    RuntimeTranslationController.php   # all front-end / submission filters
  Services/
    FormTranslationService.php         # string registration, lookup, language switching
assets/admin/
  ff-polylang-settings.js              # Vue component injected into FF's settings UI

Development notes

• No build step. The settings UI is a hand-written Vue 2 render-function component that piggybacks on Fluent Forms' already-registered Vue runtime + Element UI. Edit assets/admin/ff-polylang-settings.js directly.
• Asset injection. When Fluent Forms' fluentform_form_settings script handle is registered, the JS is appended via wp_add_inline_script(..., 'before') so it lives inside the host bundle. Otherwise it falls back to a standalone enqueue.
• Global strings sync. GlobalSettingsController keeps a schema version + dirty flag (_mfffpll_global_strings_schema_version, _mfffpll_global_strings_dirty) so global strings are re-registered only when a tracked option changes.
• Language resolution. AJAX submissions carry the language via a request key (see FormTranslationService::REQUEST_LANGUAGE_KEY), set by the fluentform/ajax_url filter so Polylang's URL-based detection survives the round trip.

FAQ

Do I need Polylang Pro? No. Both free Polylang and Polylang Pro work.

Does this conflict with Fluent Forms' WPML integration? No — this plugin only registers Polylang hooks. The two integrations don't overlap, but you should pick one translation system per site.

My existing form already has strings — will enabling translation re-scan them? Yes. Enabling a form registers its current strings immediately, and saving form changes refreshes them.

Contributing

Issues and PRs welcome at https://github.com/nkb-bd/multilingual-forms-fluent-forms-polylang.

License

GPLv2 or later. See the plugin header for the full notice.