How is «Submit Shipment» implemented?



Details: How does \Magento\Shipping\Controller\Adminhtml\Order\ShipmentLoader::load() work?

Details: How does \Magento\Sales\Model\Order\Shipment::register() work?

Details: How does \Magento\Shipping\Controller\Adminhtml\Order\Shipment\Save::_saveShipment() work?

See also:

A post was split to a new topic: In a loop creating shipments for orders. only for one order it is creating shipment after that throwing error like “registry key” already exists. How to overcome from this error?