he Object Manager refers to a fundamental component of the Magento framework. It is a dependency injection (DI) container that manages the creation and retrieval of objects throughout the system. The Object Manager is responsible for resolving dependencies between classes and providing instances of requested objects.
While the Object Manager in Magento 2 provides a convenient way to access and instantiate objects, it is worth mentioning that best practices encourage the use of dependency injection via the constructor or method injection instead of directly relying on the Object Manager. This approach improves testability, and maintainability, and adheres to the principles of SOLID design.
The Object Manager in Magento 2 serves several purposes and is used in various scenarios:
Dependency Injection: The Object Manager is the central mechanism for dependency injection in Magento 2. It automatically resolves and injects dependencies into objects, reducing the need for manual instantiation and configuration. This promotes modular and loosely coupled code.
Object Creation: The Object Manager is used to create instances of classes. Instead of directly using the new operator, developers can request objects from the Object Manager, which takes care of instantiating the appropriate class and resolving any dependencies.
Object Retrieval: The Object Manager provides a convenient way to retrieve objects from various parts of the system. It allows developers to fetch objects by their class name or interface, abstracting away the details of object lookup and instantiation.
Singleton Management: Magento 2’s Object Manager also manages singleton instances. By default, it ensures that only one instance of a class is created and shared across the system. This is useful for maintaining a single stateful instance of certain classes, such as database connections or configuration objects.
Interception and Plugin System: The Object Manager plays a vital role in Magento 2’s interception and plugin system. It enables developers to intercept and modify the behavior of Magento classes by defining plugins. Plugins are classes that can be configured to execute before, after, or around the execution of target methods, allowing for customization and extension of core functionality.