Cart Extension Architecture

Extension guidelines

• CartProcessorInterface::process() must not execute queries, as it runs multiple times per request to resolve the dependencies of the elements in the shopping cart.
• The \Shopware\Core\Checkout\Cart\CartDataCollectorInterface::collect() method must check whether the required data was already loaded. This is to avoid executing unnecessary queries on the database. loaded data will be appended to CartDataCollection.
• Line items must be created via a LineItemFactoryHandler class.
• All price calculations and adjustments must take place via an appropriate PriceCalculator, which is stored inside the Shopware\Core\Checkout\Cart\Price class.
• Cart-related functions must be mapped via corresponding Store API routes in the Shopware\Core\Checkout\Cart\SalesChannel namespace.