Add a filter for the items to apply coupons array.

[rawdreeg]

Submission Review Guidelines:

• I have followed the WooCommerce Contributing Guidelines and the WordPress Coding Standards.
• I have checked to ensure there aren't other open Pull Requests for the same update/change.
• I have reviewed my code for security best practices.
• Following the above guidelines will result in quick merges and clear and detailed feedback when appropriate.

Changes proposed in this Pull Request:

I am working on an issue where fixed_cart coupon needs to be applied to only a subset of the cart items. The items to apply coupon array is built by get_items_to_apply_coupon method in WC_Discounts class.

I propose a filter in get_items_to_apply_coupon modify the items to apply coupons to.

Closes #45790 .

How to test the changes in this Pull Request:

Using the WooCommerce Testing Instructions Guide, include your detailed testing instructions:

You can use the filter in your child's theme's function.php file.

add_filter( 'woocommerce_coupon_get_items_to_apply',  'get_items_to_apply' , 10, 2 );
function get_items_to_apply ($items_to_apply, $coupon ) {

                // Any Product ID to exclude
		$excluded_product_ids = array ( 25 ); // Replace with your test product ID.

		return array_filter( $items_to_apply, function( $item ) use ( $excluded_product_ids ) {
			return ! in_array( $item->product->get_id(), $excluded_product_ids );
		} );

	}

1. Check out this branch.
2. Create a fixed cart coupon
3. Add a few items in your cart, including the product exclude in the filter usage (above).
4. Navigate to WP Admin > WC > Orders and take a look at the order. Discount is displayed as applied to only the product allowed to accept discounts.

Changelog entry

• Automatically create a changelog entry from the details below.

Significance

• Patch
• Minor
• Major

Type

• Fix - Fixes an existing bug
• Add - Adds functionality
• Update - Update existing functionality
• Dev - Development related task
• Tweak - A minor adjustment to the codebase
• Performance - Address performance issues
• Enhancement - Improvement to existing functionality

Message

WC_Discount: Add a filter for the items to apply coupons array.

Comment

[github-actions]

Hi @budzanowski,

Apart from reviewing the code changes, please make sure to review the testing instructions as well.

You can follow this guide to find out what good testing instructions should look like:
https://github.com/woocommerce/woocommerce/wiki/Writing-high-quality-testing-instructions

[github-actions]

Test Results Summary

Commit SHA: e34fe28

Test 🧪	Passed ✅	Failed 🚨	Broken 🚧	Skipped ⏭️	Unknown ❔	Total 📊	Duration ⏱️
API Tests	259	0	0	2	0	261	0m 39s
E2E Tests	1	0	0	356	0	357	0m 31s

---

To view the full API test report, click here.
To view the full E2E test report, click here.
To view all test reports, visit the WooCommerce Test Reports Dashboard.

[budzanowski]

Looks good but we need the documentation.

[budzanowski]

This needs docblock. Please review https://developer.wordpress.org/coding-standards/inline-documentation-standards/php/ for guidance.

[rawdreeg]

Thanks @budzanowski . I added the missing docbloc here: ace39fa