How to filter all products in the woocommerce webshop with a specific tag in the code template?

Question

I need to filter the whole webshop in wordpress woocommerce by a tag. So the the webshop should only display the products if the product has a specific tag let's say (visible-shop) or something else. I know there is a visibilty option but thats not what I am looking for.

Please help.

archive-product.php

<?php
/**
 *
 * @see         https://docs.woocommerce.com/document/template-structure/
 * @author      WooThemes
 * @package     WooCommerce/Templates
 * @version     3.3.0
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}
<
get_header( 'shop' );

/**
 * Hook: woocommerce_before_main_content.
 *
 * @hooked woocommerce_output_content_wrapper - 10 (outputs opening divs for the content)
 * @hooked woocommerce_breadcrumb - 20
 * @hooked WC_Structured_Data::generate_website_data() - 30
 */
do_action( 'woocommerce_before_main_content' );

if ( have_posts() ) {

    /**
     * Hook: woocommerce_before_shop_loop.
     *
     * @hooked wc_print_notices - 10
     * @hooked woocommerce_result_count - 20
     * @hooked woocommerce_catalog_ordering - 30
     */
    do_action( 'woocommerce_before_shop_loop' );

    woocommerce_product_loop_start();

    if ( wc_get_loop_prop( 'total' ) ) {
        while ( have_posts() ) {
            the_post();

            /**
             * Hook: woocommerce_shop_loop.
             *
             * @hooked WC_Structured_Data::generate_product_data() - 10
             */
            do_action( 'woocommerce_shop_loop' );

            wc_get_template_part( 'content', 'product' );
        }
    }

    woocommerce_product_loop_end();

    /**
     * Hook: woocommerce_after_shop_loop.
     *
     * @hooked woocommerce_pagination - 10
     */
    do_action( 'woocommerce_after_shop_loop' );
} else {
    /**
     * Hook: woocommerce_no_products_found.
     *
     * @hooked wc_no_products_found - 10
     */
    do_action( 'woocommerce_no_products_found' );
}

/**
 * Hook: woocommerce_after_main_content.
 *
 * @hooked woocommerce_output_content_wrapper_end - 10 (outputs closing divs for the content)
 */
do_action( 'woocommerce_after_main_content' );

/**
 * Hook: woocommerce_sidebar.
 *
 * @hooked woocommerce_get_sidebar - 10
 */
do_action( 'woocommerce_sidebar' );

get_footer( 'shop' );

Answer 1

You need to alter the product query and you can do it this way:

add_action('woocommerce_product_query', 'product_query');

function product_query($q)
{

    $q->set('product_tag', 'visible-shop '); //Here you can define which tag you want 

}

The code above is tested and working just put it in your functions.php