Total Guide To Angular 6+ Dependency Injection — providedIn vs providers:[ ] 💉

Original 📸 by Modestas Urbonas

🤫 Psst! Do you think that NgRx or Redux are overkill for your needs? Looking for something simpler? Check out @angular-extensions/model library!

Try out @angular-extensions/model library! Check out docs & Github

I know, I know… Angular 7 is out already but this topic is as relevant as ever! Angular 6 brought us new better providedIn syntax for registration of services into Angular dependency injection mechanism.

As it turned out, this topic can evoke quite emotional responses and there is a lot of confusion across GitHub comments, Slack and Stack Overflow so let’s make this clear once and for all!

📖 What we’re going to learn

1. Dependency Injection (DI) recapitulation (optional😉)
2. The Old Way™ of doing DI in Angular — providers: []
3. The New Way™ of doing DI in Angular — providedIn: 'root' | SomeModule
4. Possible scenarios when using providedIn
5. Recommendation on how to use new syntax in your projects
6. Summary

💉 Dependency Injection