避免在WooCommerce中添加来自不同产品类别的购物车产品

Question

On WooCommerce, I have tried " Restricting cart items to be from the same product category " answer code, and it works. But if the user adds the product from the product page, the product will be in the cart.

Any advice or help please?

Answer 1

Because woocommerce_add_to_cart_validation hook is located on both WC_Cart and WC_Ajax add_to_cart() methods, so it's triggered when a product is added to cart via ajax or normally via single product pages… So the code works in all cases on add to cart event.

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Handling parent product categories too

Now " Restricting cart items to be from the same product category in WooCommerce " doesn't handle parent product categories, as WordPress has_term() conditional function doesn't handle parent terms, so parent product categories.

To make it work with parent product categories too, you will need something more elaborate:

add_filter( 'woocommerce_add_to_cart_validation', 'custom_checking_product_added_to_cart', 10, 3 );
function custom_checking_product_added_to_cart( $passed, $product_id, $quantity) {

    // HERE your alert text message
    $message = __( 'MY ALERT MESSAGE.', 'woocommerce' );

    if( ! WC()->cart->is_empty() ) {
        $term_ids = array(); // Initializing

        // Loop through product category WP_Term objects set for the current the product
        foreach( wp_get_post_terms( $product_id, 'product_cat') as $term ) {
            $terms_ids[$term->term_id] = $term->term_id; // Add the term ID to the array

            // Add the parent term ID to the array, if it exist
            if( $term->parent > 0 )
                $terms_ids[$term->parent] = $term->parent; 
        }

        // Loop through cart items
        foreach (WC()->cart->get_cart() as $cart_item ){
            if( ! has_product_categories( $product_id, $term_ids ) ) {
                $passed = false;
                wc_add_notice( $message, 'error' );
                break;
            }
        }
    }
    return $passed;
}

// Custom conditional function that handle parent product categories too
function has_product_categories( $product_id, $categories ) {
     // Initializing
    $parent_term_ids = $categories_ids = array();
    $taxonomy        = 'product_cat';

    // Convert categories term names and slugs to categories term ids
    foreach ( $categories as $category ){
        if( is_numeric( $category ) ) {
            $categories_ids[] = (int) $category;
        } elseif ( term_exists( sanitize_title( $category ), $taxonomy ) ) {
            $categories_ids[] = get_term_by( 'slug', sanitize_title( $category ), $taxonomy )->term_id;
        }
    }

    // Loop through the current product category terms to get only parent main category term
    foreach( get_the_terms( $product_id, $taxonomy ) as $term ){
        if( $term->parent > 0 ){
            $parent_term_ids[] = $term->parent; // Set the parent product category
            $parent_term_ids[] = $term->term_id; // (and the child)
        } else {
            $parent_term_ids[] = $term->term_id; // It is the Main category term and we set it.
        }
    }
    return array_intersect( $categories_ids, array_unique($parent_term_ids) ) ? true : false;
}

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

Code is tested and it works

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Restricting cart items to be only from different product categories

In the first function, replace:

if( ! has_product_categories( $cart_item['product_id'], $term_ids ) ) {

by

if( has_product_categories( $cart_item['product_id'], $term_ids ) ) {

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Related: Restricting cart items to be from the same product category in WooCommerce