ACF Gallery fix for WPML compatibility

ACF Gallery has a bit of a problem when it's used in conjunction with WPML: When you clone a post that has a gallery within, all gallery items are still on the initial language.

This comes after couple of years of not having this fixed (in the past I used some workarounds):

• https://support.advancedcustomfields.com/forums/topic/wpml-and-gallery-addon-problem/
• https://support.advancedcustomfields.com/forums/topic/acf-gallery-vs-wpml/
• https://wpml.org/forums/topic/acf-repeater-gallery-images-not-copied/
• https://wpml.org/forums/topic/problems-with-acf-gallery-and-wpml-translating/
• https://wpml.org/forums/topic/no-more-image-media-translation-module-with-acf-gallery-field/

and so on...

How it works?

This plugin hooks into WPML and iterates over all gallery items in order to update them with the correct IDs. Everything happens when you hit that translate independently button, right after you clone a page.

Known issues

• There might be an issue when you have a crazy nested structure (like a gallery inside of a repeater that's inside of a flexible content), but since I think this is a bad idea anyway, I won't do it.
• There also might be an issue when you're using File field type, but the logic goes by this: if you upload a file to a post, you'll upload files related to that language. I.e. you won't need an English PDF file to be on the Spanish version of that page.

For both of those I'm happy to accept pull requests.

How to fix existing posts?

If you already cloned a bunch of posts and need to update them automatically, you could use the following snippet (PHP 5.4 is required; if you use a lower version, you will need to update arrays their longer form):

<?php
add_action('init', function () {
    if (ICL_LANGUAGE_CODE != 'en' && class_exists('acf_gallery_wpml_compat')) {

    if (!get_option('acf_gallery_wpml_fixed_' . ICL_LANGUAGE_CODE)) {
        set_time_limit(0);
        $postTypes = get_post_types([
            'public' => true,
        ]);
        unset($postTypes['attachment']);

        foreach ($postTypes as $postType) {
            $loop_name = new WP_Query();
            $loop_name->query(array(
                "post_type" => $postType,
                "posts_per_page" => -1,
            ));
            echo "<br><h3>Converting: {$postType}</h3>";
            echo str_repeat("\n", 2048);
            while ($loop_name->have_posts()) {
                $loop_name->the_post();
                echo "<br>Converting Post: " . get_the_ID() . " - ( " . get_the_title() . " )";
                echo str_repeat("\n", 2048);
                $migration = new acf_gallery_wpml_compat(get_the_ID());
                $migration->parse_post_fields();
            }
        }

        update_option('acf_gallery_wpml_fixed_' . ICL_LANGUAGE_CODE, true);

        echo 'Migration complete!';
        die();
    }

  }
});

Once you add this, the first time you visit a page that's in a secondary language, it will run through all post types. (please update the first condition if (ICL_LANGUAGE_CODE != 'en' to your primary language). You can safetly delete this snipped after migration.

License & co

GPLv3