Automatically add the product's size as a size attribute from multiple fields and normalize the size name. [datafeedr][dfrpswc]

add_size_attribute-04.php

<?php

/**
 * Add the product's size as a size attribute for this product.
 *
 * The attribute "Size" with a slug of "size"
 * must already exist here:
 * WordPress Admin Area > Products > Attributes.
 *
 * @param array|string $value The current value of the $attribute for this $post.
 * @param string $attribute The slug of the attribute. Examples: pa_color or pa_shoe-size
 * @param array $post An array of post data including ID, post_title, post_status, etc...
 * @param array $product An array of product data returned from the Datafeedr API.
 * @param array $set A post array for this Product Set with an array key of postmeta containing all post meta data.
 * @param string $action The action the Product Set is performing. Value are either "insert" or "update".
 *
 * @return array|string The updated attribute's value.
 */
add_filter( 'dfrpswc_filter_attribute_value', function ( $value, $attribute, $post, $product, $set, $action ) {

	if ( $attribute !== 'pa_size' ) {
		return $value;
	}

	if ( isset( $product['size'] ) ) {
		return mycode_get_size( $product['size'] );
	}

	if ( isset( $product['custom1'] ) ) {
		return mycode_get_size( $product['custom1'] );
	}

	if ( isset( $product['name'] ) ) {
		return mycode_get_size( $product['name'] );
	}

	return $value;

}, 20, 6 );

/**
 * A function to normalize size attribute names.
 *
 * This returns a normalized value of a term based on a supplied
 * array of mappings of a key (desired word) mapped to an array of
 * keywords (undesired words).
 *
 * @param string $field The value to normalize.
 * @param string $default Optional. What to return if the $field value doesn't have a "normalized" value. Default: ''
 *
 * @return string Normalized attribute value.
 */
function mycode_get_size( $field, $default = '' ) {

	$map = [];

	// ++++++++++ Begin Editing Here ++++++++++

	// Small, Medium, Large Sizes
	$map['XXXS']   = [ 'xxx small' ];
	$map['XXS']    = [ 'xx small' ];
	$map['XS']     = [ 'x small' ];
	$map['Small']  = [ 'sm', 's' ];
	$map['Medium'] = [ 'md', 'med', 'm' ];
	$map['Large']  = [ 'lg', 'l' ];
	$map['XL']     = [ 'extra large', 'x large' ];
	$map['XXL']    = [ 'xx large' ];
	$map['XXXL']   = [ 'xxx large' ];

	// European Shoe Sizes
	$map['34']   = [ '34', 'UK 2' ];
	$map['34.5'] = [ '34.5', 'UK 2' ];
	$map['35']   = [ '35', 'UK 2.5' ];
	$map['35.5'] = [ '35.5', 'UK 3' ];
	$map['36']   = [ '36', 'UK 3.5' ];
	$map['36.5'] = [ '36.5', 'UK 3.5' ];
	$map['37']   = [ '37', 'UK 4' ];
	$map['37.5'] = [ '37.5', 'UK 4.5' ];
	$map['38']   = [ '38', 'UK 5' ];
	$map['38.5'] = [ '38.5', 'UK 5.5' ];
	$map['39']   = [ '39', 'UK 6' ];
	$map['39.5'] = [ '39.5', 'UK 6.5' ];
	$map['40']   = [ '40', 'UK 7' ];
	$map['40.5'] = [ '40.5', 'UK 7' ];
	$map['41']   = [ '41', 'UK 7.5' ];
	$map['41.5'] = [ '41.5', 'UK 7.5' ];
	$map['42']   = [ '42', 'UK 8' ];
	$map['42.5'] = [ '42.5', 'UK 8.5' ];
	$map['43']   = [ '43', 'UK 9' ];
	$map['43.5'] = [ '43.5', 'UK 9' ];
	$map['44']   = [ '44', 'UK 9.5' ];
	$map['44.5'] = [ '44.5', 'UK 10' ];
	$map['45']   = [ '45', 'UK 10.5' ];
	$map['45.5'] = [ '45.5', 'UK 10.5' ];
	$map['46']   = [ '46', 'UK 11' ];
	$map['46.5'] = [ '46.5', 'UK 11.5' ];
	$map['47']   = [ '47', 'UK 12' ];
	
	// ++++++++++ Stop Editing Here ++++++++++

	$terms = [];

	foreach ( $map as $key => $keywords ) {

		if ( preg_match( '/\b' . preg_quote( $key, '/' ) . '\b/iu', $field ) ) {
			$terms[] = $key;
		}

		foreach ( $keywords as $keyword ) {
			if ( preg_match( '/\b' . preg_quote( $keyword, '/' ) . '\b/iu', $field ) ) {
				$terms[] = $key;
			}
		}
	}

	if ( ! empty( $terms ) ) {
		return implode( WC_DELIMITER, array_unique( $terms ) );
	}

	return $default;
}