Shopware plugin to illustrate how you can extend a product entity in various ways
bin/console plugin:install --activate SwagTrainingProductEntityExtensionAn entity extension in a separate table, added to the entity via associations ($criteria->addAssociation())
This is supported by the core. You own data will reside in a separate table which is joined by the association.
Simple array extension added via event observer \SwagTraining\ProductEntityExtension\Subscriber\ProductSubscriber::onProductsLoaded()
This is supported by the core. Unfortunately, all of the data loading needs to happen by you, which leads to additional queries.
Array Extension field added via \SwagTraining\ProductEntityExtension\Extension\Content\Product\ExampleExtension::extendFields()
This is supported by the core. Unfortunately, all of the data loading needs to happen by you, which leads to additional queries.
A Product Entity Extension field added via \SwagTraining\ProductEntityExtension\Extension\Content\Product\ExampleExtension::extendFields() as a Runtime field.
This is supported by the core. Unfortunately, all of the data loading needs to happen by you, which leads to additional queries.
A new class ExtendedProductDefinition extends the original core ProductDefinition, not by adding a simple service rewrite, but by adding a compiler pass. Next, the new definition also leads to a new entity class and new collection class. And the field is added directly to the product table with a migration
This currently does not work, because data-loading is not happening for some reason.
However, this method is performant (like with associations) but totally hacky: Do not use this.
Decoration of ProductDefinition
This is not working: The Shopware\Core\Framework\DataAbstractionLayer\EntityDefinition::$registry is not initialized properly. Also, the constructor EntityDefinition::__construct is final so can't be extended.