When you query for a single post via URI, then the language is ignored

[MobyDigg]

When you query for a single post via URI, then the language parameter in the URL is ignored.
Query returns only the post in the standard language:

query MyQuery {
  teamMember(id: "/fr/team_members/lorem-ipsum/", idType: URI) {
    slug
    language {
      code
    }
    uri
  }
}

It should return the the French version for the query above.

[tim9009]

I have a similar issue now and it's blocking my entire project. Did you find a solution yet @MobyDigg?

In my case if I query the main language version of the cpt by URI I get the expected result.

If I query the translated version of the cpt by URI (the exact URI, copied from wp-admin, including a translated rewrite slug) I get an internal server error "Cannot return null for non-nullable field "Article.databaseId".".

If I query the cpt by using the untranslated URI and just replace the final slug with the translated one I get the translated cpt. The returned URI field is exactly the same as in wp-admin.

[MobyDigg]

Unfortunately not. I had to create a work-around… In the end I queried all posts and then filtered by the slug. Obviously that is not really performant.

[gorkalaucirica]

This filter worked for me:

add_filter(
    'request',
    function ( array $query_args) {
        if ( isset( $query_args['name'] ) ) {
            $allowed_post_types = get_post_types( [
                'show_in_graphql' => true,
                'public'          => true,
            ] );

            $post_type = 'post';
            if ( isset( $query_args['post_type'] ) && in_array( $query_args['post_type'], $allowed_post_types, true ) ) {
                $post_type = $query_args['post_type'];
            }

            $post = get_page_by_path( $query_args['name'], 'OBJECT', $post_type );
            $translations = pll_get_post_translations($post->ID);
            $post_id = $translations[$query_args['lang']] ?? null;

            $query_args["page_id"] = $post_id;
        }
        return $query_args;
}, 	10, 2);

It's based on how wpgraphql's NodeResolver works

[pangeaos]

hi @gorkalaucirica, any help how to implement this filter? or how it works. thanks.

[esamattis]

This is actually a duplicate of #35

Might want to read this #35 (comment)

Thank you for the filter workaround @gorkalaucirica

[simplenotezy]

Unfortunately I didn't have much luck with @gorkalaucirica's filter. Instead, this fixed it for my use-case:

/**
 * Bugfix: prevent fetching pages from other languages. Without below filter, /de/about-us would resolve
 * to the english post called /en/about-us, which will give SEO issues. It also fixes an issue if two
 * posts in two different languages had the same post_name, the wrong one would/could be resolved
 * depending on what language you was requesting
 *
 * https://github.com/valu-digital/wp-graphql-polylang/issues/35
 */

add_filter( 'request', function ( $query_args) {
    if(isset($query_args['uri']) && $query_args['uri'] && isset($query_args['lang'])) {
        $explodedUri = explode('/', $query_args['uri']);
        if($explodedUri[0] !== $query_args['lang']) {
            // query was made without language slug in URI
            return $query_args;
        }

        unset($explodedUri[0]); // remove language slug from URL
        $uriWithoutLang = implode('/', $explodedUri); // rebuild the URI without the slug in front

        // search for the URI (post_name) without the language slug
        // as well as including the requested $lang in the query
        $query = new \WP_Query([
            'post_type'      => isset($query_args['post_type']) ? $query_args['post_type'] : 'any',
            'lang'           => $query_args['lang'],
            'posts_per_page' => 1,
            'post_status'    => 'publish',
            'name'           => $uriWithoutLang
        ]);

        if($query->have_posts() && isset($query->posts[0])) {
            // if we found a post, that's most likely the post we're looking for,
            // in the given language
            $query_args['p'] = $query->posts[0]->ID;
        } else {
            // we weren't able to find a post/page with the given URI and language
            // reset the query_args to return an empty response (to generate 404 page)
            // alternatively remove below line, if you wish to fallback to default behaviour
            // which may cause SEO issues, depending on your setup

            // some custom post types, or posts which are parents of other pasts, and thus have
            // a more complicated structure, we can run it through pll_get_post_language
            // and check if the post language corresponds to the requested language
            if(function_exists('pll_get_post_language')) {
                $post = get_page_by_path($uriWithoutLang);

                if($post && pll_get_post_language($post->ID) !== $query_args['lang']) {
                    $query_args = [];
                }
            }
        }
    }
    return $query_args;
}, 	10, 2);

It's not the prettiest, but it does it's job. We had an issue if two pages was called the same, e.g. /de/about us and /en/about-us, when requesting the /de/about-us, it would resolve the english version.

Also we had an issue where if you requested an english slug, on the german prefix, if a german page did not exist with that name, it would return the english page - on the german site. Above filter also fixes that.