Understanding the `woocommerce_product_query` Hook in WooCommerce

The woocommerce_product_query hook is a powerful tool in WooCommerce that allows developers to modify or extend the default product queries. Whether you need to customize product displays, filter products dynamically, or add custom logic, this hook offers the flexibility to achieve it without altering core WooCommerce functionality.

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What is woocommerce_product_query?

The woocommerce_product_query hook provides access to the WC_Query object before WooCommerce retrieves the products from the database. This hook can be used to modify query parameters such as product categories, tags, meta queries, or other arguments, giving you control over the products displayed in the shop or other product-related pages.

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Hook Syntax

Here’s the basic syntax for using the woocommerce_product_query hook:

add_action('woocommerce_product_query', 'custom_modify_product_query');

function custom_modify_product_query($query) {
    // Modify the query parameters here
}

The $query parameter is an instance of the WC_Query object, allowing you to set or adjust its properties.

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Use Cases

1. Exclude Products from a Specific Category

If you want to exclude products from a particular category, you can use the set method to modify the query arguments:

add_action('woocommerce_product_query', 'exclude_category_from_shop');

function exclude_category_from_shop($query) {
    $tax_query = $query->get('tax_query');

    $tax_query[] = array(
        'taxonomy' => 'product_cat',
        'field'    => 'slug',
        'terms'    => 'excluded-category', // Replace with your category slug
        'operator' => 'NOT IN',
    );

    $query->set('tax_query', $tax_query);
}

2. Display Only Featured Products

To show only featured products on the shop page, modify the meta query:

add_action('woocommerce_product_query', 'show_only_featured_products');

function show_only_featured_products($query) {
    $meta_query = $query->get('meta_query');

    $meta_query[] = array(
        'key'   => '_featured',
        'value' => 'yes',
    );

    $query->set('meta_query', $meta_query);
}

3. Sort Products by Custom Field

If you have a custom field and want to sort products based on its value, use the orderby parameter:

add_action('woocommerce_product_query', 'sort_products_by_custom_field');

function sort_products_by_custom_field($query) {
    $query->set('meta_key', 'custom_field'); // Replace with your custom field key
    $query->set('orderby', 'meta_value_num');
    $query->set('order', 'ASC');
}

4. Limit Products Displayed on Shop Page

To limit the number of products displayed per page, adjust the posts_per_page parameter:

add_action('woocommerce_product_query', 'limit_products_per_page');

function limit_products_per_page($query) {
    $query->set('posts_per_page', 12); // Set the desired number of products per page
}

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Debugging Tips

When working with the woocommerce_product_query hook, debugging is essential to ensure your modifications work as expected. Here are some tips:

1. Log the Query: Use error_log to output the modified query parameters for debugging:

   error_log(print_r($query->query_vars, true));

1. Test in Staging: Always test your changes in a staging environment before applying them to production.

2. Check Conflicts: Ensure your customizations don’t conflict with other plugins or themes.

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Best Practices

1. Use Conditional Tags:

Limit your customizations to specific pages using WooCommerce conditional tags like is_shop() or is_product_category().

   if (!is_shop()) {
       return;
   }

1. Minimize Query Modifications:

Avoid overloading the query with unnecessary modifications, as it can impact site performance.

1. Follow Coding Standards:

Adhere to WordPress and WooCommerce coding standards for maintainable and readable code.

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Conclusion

The woocommerce_product_query hook is an essential tool for developers looking to customize WooCommerce product queries dynamically. With careful implementation and adherence to best practices, you can leverage this hook to create tailored product displays that meet your website’s needs.

By understanding its functionality and flexibility, you can unlock a wide range of possibilities to enhance your WooCommerce store.