Préfixer les articles par l’URL du page for posts (avec WPML)

filtre.php

<?php

add_filter( 'post_link', 'w_post_link', 10, 3 );
function w_post_link( $url, $post, $leavename=false ) {
	if ( $post->post_type == 'post' ) {
        global $sitepress;
        $lang = apply_filters( 'wpml_post_language_details', 'fr', $post->ID );
        $base = get_permalink( icl_object_id( get_option( 'page_for_posts' ), 'page', true, $lang['language_code'] ) );
		$url = str_replace( $sitepress->language_url( $lang['language_code'] ), $base, $url );
	}
	return $url;
}

add_filter( 'post_rewrite_rules', 'w_post_rewrite_rules' );
function w_post_rewrite_rules( $rules ) {
    global $sitepress;
    foreach ( apply_filters( 'wpml_active_languages', '', array( 'skip_missing' => 0 ) ) as $l => $lang ) {
        $base = get_permalink( icl_object_id( get_option( 'page_for_posts' ), 'page', true, $l ) );
        $url = str_replace( $sitepress->language_url( $l ), '', $base );
        $rules[ $url . '([^/]+)(?:/([0-9]+))?/?$'] = 'index.php?name=$matches[1]&page=$matches[2]';
    }
    return $rules;
}

Ce code a été écrit vite fait, pour les besoins d’un projet, et peut être amélioré :)