Magento 2: Dependency Injection Adobe Commerce (formerly known as Magento) uses dependency injection (DI) to replace functionality provided by the Mage class in Magento 1.x. Dependency injection is a design pattern that allows an object to declare its dependencies to an external object that supplies those dependencies. The dependencies declared by an object are usually class interfaces, and the dependencies provided by the external object are concrete implementations for those interfaces.

1. Magento Basics -
Dependency Injection
Abid H. Malik • 22.06.2023

2. Abid H. Malik
★ 20+ years experience in Software
Industry.
★ 13 Years experience in Magento
and other ecommerce platforms.
★ 6+ Years as corporate trainer and
content developer.
malikabid2006@gmail.com

3. Agenda
1. Dependency Injection
2. Object Manager
3. di.xml
4. Advantages of DI
Dependency Injection

4. What is DI?
● A design pattern that allows an object to declare its
dependencies to an external object that supplies those
dependencies.
● Dependencies are declared as Interfaces.
● Dependencies are provided as concrete classes.

5. What is Object Manager
● A service class in Adobe commerce / magento.
● Instantiates objects.
● Uses class constructors and di.xml to retrieve
information about the objects to be instantiated.
● Classes should not depend on Object Manager.
● Custom factories are exceptions

6. Dependency Types
● Injectable (singletons)
● Newable / non-injectable
○ Obtained by creating new class instance every time
○ Factories.

7. Injection types
● Constructor Injection
● Method Injection
● Optional Dependencies

8. Injection types

9. DI Configuration (di.xml)
● Purpose
○ Configuring dependencies
○ Overriding classes
○ Creating plugins
○ Creating virtual sub-classes
○ Defining preferences:
● Initial (app/etc/di.xml)
● Global (<moduleDir>/etc/di.xml)
● Area-specific (<moduleDir>/etc/<area>/di.xml)

10. Benefits of DI
● Loose coupling of code
● Easy maintenance
● Focus on what a class does.
● Flexibility and scalability

11. Best Practices
● Avoid Circular dependencies.
● Make sure d.xml configuration are correct.
● Avoid tight coupling of classes
● Keep number of dependencies to a minimum.
● Use interfaces to define dependencies.
● Use area-specific di.xml files.

12. Thank you!
● Keep Smiling.
● Send your feedback to
malikabid2006@gmail.com