Create new product attribute programmatically in Woocommerce - php

Question

How can I create attributes for WooCommerce from a plugin?
I find only :
wp_set_object_terms( $object_id, $terms, $taxonomy, $append);
From this stack-question
But this approach required id of some product. I need to generate some attributes not attached to any products.

Answer 1

To create a term you can use wp_insert_term()
like so:
wp_insert_term( 'red', 'pa_colors' );
where colors is the name of your attribute. The taxonomy name of an attribute is always prepended by pa_.
Edit Attributes are merely custom taxonomies. Or you could say they are dynamic taxonomies that are manually created by the user in the back-end. Still, all the same, custom taxonomy rules apply.
You can see the source code here which loops through the attributes and runs register_taxonomy() on each. So to create a new attribute (remember it is just a taxonomy) then you need to run register_taxonomy() and simple prepend pa_ to the start of the taxonomy name.
Mimicking some of the values of the taxonomy args from core would get you something like this for a 'Colors' attribute.
/**
* Register a taxonomy.
*/
function so_29549525_register_attribute() {
$permalinks = get_option( 'woocommerce_permalinks' );
$taxonomy_data = array(
'hierarchical' => true,
'update_count_callback' => '_update_post_term_count',
'labels' => array(
'name' => __( 'My Colors', 'your-textdomain' ),
'singular_name' => __( 'Color', 'your-textdomain' ),
'search_items' => __( 'Search colors', 'your-textdomain' ),
'all_items' => __( 'All colors', 'your-textdomain' ),
'parent_item' => __( 'Parent color', 'your-textdomain' ),
'parent_item_colon' => __( 'Parent color:', 'your-textdomain' ),
'edit_item' => __( 'Edit color', 'your-textdomain' ),
'update_item' => __( 'Update color', 'your-textdomain' ),
'add_new_item' => __( 'Add new color', 'your-textdomain' ),
'new_item_name' => __( 'New color', 'your-textdomain' )
),
'show_ui' => false,
'query_var' => true,
'rewrite' => array(
'slug' => empty( $permalinks['attribute_base'] ) ? '' : trailingslashit( $permalinks['attribute_base'] ) . sanitize_title( 'colors' ),
'with_front' => false,
'hierarchical' => true
),
'sort' => false,
'public' => true,
'show_in_nav_menus' => false,
'capabilities' => array(
'manage_terms' => 'manage_product_terms',
'edit_terms' => 'edit_product_terms',
'delete_terms' => 'delete_product_terms',
'assign_terms' => 'assign_product_terms',
)
);
register_taxonomy( 'pa_my_color', array('product'), $taxonomy_data );
}
add_action( 'woocommerce_after_register_taxonomy', 'so_29549525_register_attribute' );
Update 2020-11-18
Attribute taxonomies are stored in the {$wpdb->prefix}woocommerce_attribute_taxonomies database table. And from there WooCommerce runs register_taxonomy() on each one that's found in the table. So in order to create an attribute taxonomy, a row should be added to this table. WooCommerce has a function wc_create_attribute() that will handle this for us. (Since 3.2+).
My conditional logic to test if the attribute exists is not the greatest and I would advise using some kind of version option in your plugin's update routine. But as an example of using wc_create_taxonomy() this should insert an attribute called "My Color".
/**
* Register an attribute taxonomy.
*/
function so_29549525_create_attribute_taxonomies() {
$attributes = wc_get_attribute_taxonomies();
$slugs = wp_list_pluck( $attributes, 'attribute_name' );
if ( ! in_array( 'my_color', $slugs ) ) {
$args = array(
'slug' => 'my_color',
'name' => __( 'My Color', 'your-textdomain' ),
'type' => 'select',
'orderby' => 'menu_order',
'has_archives' => false,
);
$result = wc_create_attribute( $args );
}
}
add_action( 'admin_init', 'so_29549525_create_attribute_taxonomies' );

Answer 2

For Woocommerce 3+ (2018)
To create a new product attribute from a label name use the following function:
function create_product_attribute( $label_name ){
global $wpdb;
$slug = sanitize_title( $label_name );
if ( strlen( $slug ) >= 28 ) {
return new WP_Error( 'invalid_product_attribute_slug_too_long', sprintf( __( 'Name "%s" is too long (28 characters max). Shorten it, please.', 'woocommerce' ), $slug ), array( 'status' => 400 ) );
} elseif ( wc_check_if_attribute_name_is_reserved( $slug ) ) {
return new WP_Error( 'invalid_product_attribute_slug_reserved_name', sprintf( __( 'Name "%s" is not allowed because it is a reserved term. Change it, please.', 'woocommerce' ), $slug ), array( 'status' => 400 ) );
} elseif ( taxonomy_exists( wc_attribute_taxonomy_name( $label_name ) ) ) {
return new WP_Error( 'invalid_product_attribute_slug_already_exists', sprintf( __( 'Name "%s" is already in use. Change it, please.', 'woocommerce' ), $label_name ), array( 'status' => 400 ) );
}
$data = array(
'attribute_label' => $label_name,
'attribute_name' => $slug,
'attribute_type' => 'select',
'attribute_orderby' => 'menu_order',
'attribute_public' => 0, // Enable archives ==> true (or 1)
);
$results = $wpdb->insert( "{$wpdb->prefix}woocommerce_attribute_taxonomies", $data );
if ( is_wp_error( $results ) ) {
return new WP_Error( 'cannot_create_attribute', $results->get_error_message(), array( 'status' => 400 ) );
}
$id = $wpdb->insert_id;
do_action('woocommerce_attribute_added', $id, $data);
wp_schedule_single_event( time(), 'woocommerce_flush_rewrite_rules' );
delete_transient('wc_attribute_taxonomies');
}
Code goes in function.php file of your active child theme (or active theme). Tested and works.
Based on:
Product Attribute wc_create_attribute() function code (Woocommerce 3.2+).
Create programmatically a variable product and two new attributes in Woocommerce
Related: Create programmatically a product using CRUD methods in Woocommerce 3