How Dependency Injection In
In this video, we will see how the Dependency Injection (#DI) works in #angular. We will also see the Inversion Of Control (IoC) principle, and the Dependency Inversion Principle (DIP).
The Dependency Injection is a design pattern under the umbrella of the Inversion Of Control principle.
In Angular Providers, when we use the #useClass, Angular will try to create a new class instance.
When we use #useExisting, we tell Angular to use an existing class instance.
In this example, the correct approach is to use #useExisting since the loggers are singleton and we don't need to create a new instance.
Chapters:
0:00 Intro
0:22 manually create class instances
5:14 dependency inversion principle
11:15 angular dependency injection (IoC)
16:55 abstractions vs concrete implementations
22:20 summary
Code: https://github.com/profanis/codeShots...
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