Here is a custom function that will show your custom message on cart page, with the category archive pages link for the first product added to cart.
If a product without a category is added to cart, nothing is displayed.
Optionally you can also display it on checkout page (uncommenting last line).
Here is this code:
function cart_custom_message() {
if( !WC()->cart->is_empty ){
//Iterating each item in the cart
foreach ( WC()->cart->get_cart() as $item ) {
// Get the product categories object of the current item
$categories_obj = get_the_terms( $item['product_id'], 'product_cat' );
if($categories_obj) break; // when an item has a product category, stops the loop
}
if($categories_obj) {
//Iterating each category of the first item
foreach ( $categories_obj as $category ) {
break; // stop the loop to on the first category
}
$category_id = $category->term_id; // the category id
$category_name = $category->name; // the category name
$category_slug = $category->slug; // the category slug
$category_url = get_term_link( $category_slug, 'product_cat' ); // the link to category archive pages
// Your message (translatable)
$message = __("Add more T-shirts from <a href='$category_url'><strong>$category_name</strong></a> category and get a discount!", "your_theme_domain");
echo "<div class='woocommerce-info'>$message</div>";
}
}
}
// Display message on cart page
add_action('woocommerce_before_cart', 'cart_custom_message');
// Display message on checkout page (optionally, if needed, uncomment the line below)
// add_action('woocommerce_before_checkout_form', 'cart_custom_message', 5);
Code goes in function.php file of your active child theme (or theme) or also in any plugin file.
This code is tested and fully functional.
References: