We have tags and categories in WooCommerce. However, there is a significant distinction between collections and categories. Your store’s categories serve as a navigational aid. A collection is a set of products that are arranged for convenience of use or that have a common feature.

We don’t have collections in WooCommerce. Let’s learn how to use custom taxonomy to create collections. We must first register Collections, a custom taxonomy.

Below code adds a taxonomy called Collections.

// hook it to woocommerce_init
add_action( 'woocommerce_init', 'woocommerce_collections_init' );

function woocommerce_collections_init() {
 $labels = [
  'name'                       => esc_html__( 'Collections', 'wc-product-collections' ),
  'singular_name'              => esc_html__( 'Collection', 'wc-product-collections' ),
  'menu_name'                  => esc_html__( 'Collections', 'wc-product-collections' ),
  'all_items'                  => esc_html__( 'All Collections', 'wc-product-collections' ),
  'edit_item'                  => esc_html__( 'Edit Collection', 'wc-product-collections' ),
  'view_item'                  => esc_html__( 'View Collection', 'wc-product-collections' ),
  'update_item'                => esc_html__( 'Update Collection', 'wc-product-collections' ),
  'add_new_item'               => esc_html__( 'Add New Collection', 'wc-product-collections' ),
  'new_item_name'              => esc_html__( 'New Collection Name', 'wc-product-collections' ),
  'parent_item'                => esc_html__( 'Parent Collection', 'wc-product-collections' ),
  'parent_item_colon'          => esc_html__( 'Parent Collection:', 'wc-product-collections' ),
  'search_items'               => esc_html__( 'Search Collections', 'wc-product-collections' ),
  'popular_items'              => esc_html__( 'Popular Collections', 'wc-product-collections' ),
  'back_to_items'              => esc_html__( '← Go to Collections', 'wc-product-collections' ),
  'separate_items_with_commas' => esc_html__( 'Separate collections with commas', 'wc-product-collections' ),
  'add_or_remove_items'        => esc_html__( 'Add or remove collections', 'wc-product-collections' ),
  'choose_from_most_used'      => esc_html__( 'Choose from the most used collections', 'wc-product-collections' ),
  'not_found'                  => esc_html__( 'No collections found', 'wc-product-collections' )
 ];

 $args = [
  'hierarchical'       => true,
  'labels'             => $labels,
  'show_ui'            => true,
  'query_var'          => true,
  'public'             => true,
  'publicly_queryable' => true,
  'show_in_menu'       => true,
  'show_in_rest'       => true,
  'show_admin_column'  => true,
  'rewrite'            => [
   'slug'         => apply_filters( 'wc_product_taxonomy_slug', 'collections' ),
   'hierarchical' => true,
   'with_front'   => apply_filters( 'wc_product_taxonomy_with_front', true )
  ]
 ];

 // register a taxonomy
 register_taxonomy( 'collections', [ 'product' ], $args );
}

Now we need to add a field to this WooComerce taxonomy.

add_action( 'collections_add_form_fields', 'add_term_fields' );
add_action( 'collections_edit_form_fields', 'edit_form_fields', 10, 2 );

function add_term_fields( $taxonomy ) {
 ?>
  <div class="form-field">
   <label for="price_range">Price Range</label>
   <input type="number" name="price_range" id="price_range" />
   <p>Put a price like Under 900</p>
  </div>
 <?php
}

function edit_form_fields( $term, $taxonomy ) {

 // get meta data value
 $price_range = get_term_meta( $term->term_id, 'price_range', true );

 ?><tr class="form-field">
  <th><label for="price_range">Price Range</label></th>
  <td>
   <input name="price_range" id="price_range" type="number" value="<?php echo esc_attr( $price_range ) ?>" />
   <p>Put a price like Under 900</p>
  </td>
 </tr>
<?php
}


// save fields  
add_action( 'created_collections', 'wc_product_save_term_fields' );
add_action( 'edited_collections', 'wc_product_save_term_fields' );
function wc_product_save_term_fields( $term_id ) {
 
 update_term_meta(
  $term_id,
  'price_range',
  sanitize_text_field( $_POST[ 'price_range' ] )
 );
 
}

Now, we need a function which will take a price range and return the IDs.

function get_ids_on_price_range($value='100') {
 $IDs = array();
 $query = array(
     'post_status' => 'publish',
     'post_type' => 'product',
     'posts_per_page' => 99999999,
     'meta_query' => array(
         array(
             'key' => '_price',
             'value' => array(0, $value),
             'compare' => 'BETWEEN',
             'type' => 'NUMERIC'
         )
     )
 );

 $wpquery = new WP_Query($query); // return 10 products within the price range 50 - 100
 foreach ($wpquery->posts as $key => $value) {
  $IDs[] = $value->ID;
 }
 return $IDs;
}

Now, we need to run the process when the product is created or saved. We have hardcoded the term_id here, but this code can be improved. We can run a cronjob instead of save_post_product hook.

function wpdocs_product_meta( $post_id ) {
 // Check the logged in user has permission to edit this post
 if ( ! current_user_can( 'manage_options' ) ) {
  return $post_id;
 }

 $term_id = 30; // term id: change it 

 // get meta data value
 $price_range = get_term_meta( $term_id, 'price_range', true );

 $IDs = get_ids_on_price_range($price_range);

 //print_r($IDs);

 foreach ($IDs as $key => $value) {
  // code...
  wp_set_post_terms( $value, $term_id, 'collections' );
 }
 //die;
}
add_action( 'save_post_product', 'wpdocs_product_meta' );

Here is the medium link to above article: https://medium.com/@kish2011_/collections-in-woocommerce-like-shopify-b18b6f9e6f9a

If you are looking for a complete solution for automated Collections creation, then email me at kishore @ upnrunn.com