Two sets of url one content?

Question

How can I configure to have two sets of URL that actually using the same content?

For example:

(set 1)

samplesite.com
samplesite.com/about/
samplesite.com/contact/
samplesite.com/projects/

(set 2)

samplesite.com/fr/
samplesite.com/fr/about/
samplesite.com/fr/contact/
samplesite.com/fr/projects/

And then in my templates, I would like to check whether the request has fr or without.

Is this possible without any plugin?

Answer 1

You can create custom post type to manage your secondary content (multilanguage i suppose) and set these /fr/ your CPT rewrite base.

Create a CPT function add this to your function.

$rewrite = array(
    'slug'                  => 'fr',
    'with_front'            => false,
    'pages'                 => true,
    'feeds'                 => true,
);

After that set CPT rewrite option to rewrite => $rewrite. Not on same content but easy solution for your problem.

Sample CPT code for you secondary content;

    function secondary_content_french_post_type() {

    $labels = array(
        'name'                  => _x( 'French', 'Post Type General Name', 'text_domain' ),
        'singular_name'         => _x( 'French', 'Post Type Singular Name', 'text_domain' ),
        'menu_name'             => __( 'French', 'text_domain' ),
        'name_admin_bar'        => __( 'French', 'text_domain' ),
        'archives'              => __( 'Item Archives', 'text_domain' ),
        'attributes'            => __( 'Item Attributes', 'text_domain' ),
        'parent_item_colon'     => __( 'Parent Item:', 'text_domain' ),
        'all_items'             => __( 'All Items', 'text_domain' ),
        'add_new_item'          => __( 'Add New Item', 'text_domain' ),
        'add_new'               => __( 'Add New', 'text_domain' ),
        'new_item'              => __( 'New Item', 'text_domain' ),
        'edit_item'             => __( 'Edit Item', 'text_domain' ),
        'update_item'           => __( 'Update Item', 'text_domain' ),
        'view_item'             => __( 'View Item', 'text_domain' ),
        'view_items'            => __( 'View Items', 'text_domain' ),
        'search_items'          => __( 'Search Item', 'text_domain' ),
        'not_found'             => __( 'Not found', 'text_domain' ),
        'not_found_in_trash'    => __( 'Not found in Trash', 'text_domain' ),
        'featured_image'        => __( 'Featured Image', 'text_domain' ),
        'set_featured_image'    => __( 'Set featured image', 'text_domain' ),
        'remove_featured_image' => __( 'Remove featured image', 'text_domain' ),
        'use_featured_image'    => __( 'Use as featured image', 'text_domain' ),
        'insert_into_item'      => __( 'Insert into item', 'text_domain' ),
        'uploaded_to_this_item' => __( 'Uploaded to this item', 'text_domain' ),
        'items_list'            => __( 'Items list', 'text_domain' ),
        'items_list_navigation' => __( 'Items list navigation', 'text_domain' ),
        'filter_items_list'     => __( 'Filter items list', 'text_domain' ),
    );
//This is Rewrite Code
    $rewrite = array(
        'slug'                  => 'fr',
        'with_front'            => false,
        'pages'                 => true,
        'feeds'                 => true,
    );
//This is Rewrite Code
    $args = array(
        'label'                 => __( 'French', 'text_domain' ),
        'description'           => __( 'French', 'text_domain' ),
        'labels'                => $labels,
        'supports'              => array( 'title', 'editor', 'custom-fields','comments','thumbnail' ),
        'taxonomies'            => array( 'category' ),
        'hierarchical'          => false,
        'public'                => true,
        'show_ui'               => true,
        'show_in_menu'          => true,
        'menu_position'         => 10,
        'menu_icon'             => 'dashicons-nametag',
        'show_in_admin_bar'     => true,
        'show_in_nav_menus'     => false,
        'can_export'            => true,
        'exclude_from_search'   => false,
        'publicly_queryable'    => true,
        'rewrite'               => $rewrite,
        'capability_type'       => 'post',
        'show_in_rest'          => false,
    );
    register_post_type( 'french', $args );

}
add_action( 'init', 'secondary_content_french_post_type', 0 );

Answer 2

My answer with the help from Sally CJ in this question:

/**
 * Add new rewrite rule
 */
function create_new_url_querystring() {
    // https://wordpress.stackexchange.com/questions/60173/rewrite-rule-for-multilingual-website-like-qtranslate
    add_rewrite_rule(
        '^fr/?$',
        'index.php?&page_id=2&lang=fr',
        'top'
    );

    add_rewrite_rule(
        '^fr/(.?.+?)(?:/([0-9]+))?/?$',
        'index.php?pagename=$matches[1]&page=$matches[2]',
        'top'
    );

    add_rewrite_rule(
        'fr/project/(.+?)(?:/([0-9]+))?/?$',
        'index.php?project=$matches[1]&page=$matches[2]',
        'top'
    );

    // flush_rewrite_rules();
    global $wp_rewrite;
    $wp_rewrite->flush_rules();
}
add_action('init', 'create_new_url_querystring');

/**
 * Usage: get_query_var('lang');
 */
function query_vars($query_vars) {
    $query_vars[] = "lang";
    return $query_vars;
}
add_filter('query_vars', 'query_vars');

/**
 * Cancel canonical redirect on home page.
 * https://wordpress.stackexchange.com/questions/311476/add-rewrite-rule-to-call-front-page-php
 */
add_action('template_redirect', function() {
    if (is_front_page()) {
        remove_action('template_redirect', 'redirect_canonical');
    }
}, 0);