Magento 2 Development Quick Start Guide

Argument injection

Argument injection is done via preference and type definitions within the di.xml.

By performing a lookup for the <preference string across the entire <MAGENTO_DIR> directory's di.xml files, we can see that Magento uses hundreds of preference definitions, spread across the majority of its modules.

Let's take a quick look at one of the __construct method, of the type Magento\Eav\Model\Attribute\Data\AbstractData:

public function __construct(    \Magento\Framework\Stdlib\DateTime\TimezoneInterface $localeDate,    \Psr\Log\LoggerInterface $logger,    \Magento\Framework\Locale\ResolverInterface $localeResolver) {    $this->_localeDate = $localeDate;    $this->_logger = $logger;    $this->_localeResolver = $localeResolver;}

We can find the