CTX Feed Free — fix empty additional image tags

Developed a custom solution via MU-plugin for the free version of the CTX Feed plugin in WordPress/WooCommerce.

What was implemented:
- checking for the presence of additional images for the product;
- automatic addition of additional_image_link tags in the feed only for products that actually have extra photos;
- exclusion of empty tags from the Google Merchant XML feed;
- compatibility with the free version of CTX Feed without the need to purchase PRO;
- the solution works automatically without manual editing of products.

What problem it solves:

In the free version of CTX Feed, empty additional image tags could appear in the feed for products without an image gallery. This created:

- errors and warnings in Google Merchant Center;
- a "dirty" XML feed;
- validation issues for products.

After the improvement:

- only valid additional image links are included in the feed;
- Merchant receives a clean XML without empty tags;
- there is no need to purchase the PRO functionality of the plugin.

Technologies:

#WordPress #WooCommerce #CTXFeed #GoogleMerchant #PHP #XML #GoogleShopping #MerchantCenter #MUPlugin #WooCommerceDevelopment #CustomPlugin #FeedOptimization #Ecommerce

What else I can improve:
- custom fields in feeds;
- conditional logic for XML/CSV feeds;
- optimization of Google Merchant feeds;
- automation of WooCommerce;
- enhancement of free plugins for business tasks;
- custom hooks / filters / feed processing.