Angular’s Dependency Injection: A Blessing or a Curse?

Angular is a controversial framework among developers that either loved or hated, with its fancy features and modern approaches to building web applications. One of the core features that stands out is dependency injection.

You might wonder, “What on Earth is that?”. Well it is actually come from one of the fundamentals of the Object Oriented Programming called Dependency Inversion. You might quick search on google to cover because in this post we are not going to. I would like to focus on the Angular as much as possible to not bore you 🙂

Let’s Discover The Dependency Injection!

Dependency injection, the magical power in Angular that I like most, is a technique that allows a class to receive its dependencies from an external source. The result? A clean and modular codebase, easier testing, and improved reusability.

Some might argue that dependency injection is just another “unnecessary complexity” of Angular. Most of ex react developers finds that Angular is overloaded with of tons features and they have valid points for sure. Angular is a large framework while react is just a vanilla library. They have different concerns overall.

Dependency Injection is one of the features that you would possibly like most. We can develop a frontend application just the way we did with the backend applications. When the frontend technologies evolved over the years, frontend applications became more larger and complex than it used to be. In order to avoid the complexity and provide more clean and robust systems we need such features which we were using for a very long time on backend applications.

Of course these are my ideas and one other may think differently then I do. There I would like to demonstrate some pitfalls and misconceptions that developers face when using it in Angular

Benefits of Dependency Injection in Angular:

1. Easier Testing: DI makes it simple to replace real dependencies with mock ones, which is great for testing your code without needing the actual services.
2. Loose Coupling: Components and services are not tightly bound to each other. This makes the system more flexible and easier to maintain. Via dependency injection you can override or provide different implementations without touching components – or – You can change an implementation of a business logic with one touch from whole application. Saves us times and prevents possible bugs.
3. Reusability: You can use the same service across different parts of your application without duplicating code.
4. Maintainability: DI promotes a cleaner code structure, making it easier to understand and modify.
5. Scalability: DI helps manage complex applications by organizing dependencies in a manageable way.
6. Configuration: Angular’s DI system allows you to easily configure which implementation of a service to use, making it adaptable to different situations.

Disadvantages of Dependency Injection in Angular:

1. Learning Curve: Beginners might find it difficult to understand how DI works and how to properly use it. But you can find lots of tutorials across the internet. There are many resourcefull tutorials on official website, medium and blogs.
2. Initial Setup: Setting up DI can be complex and may require more boilerplate code initially. For a small project it might look like a waste of time but when project get larger, it saves incredible time.
3. Debugging Issues: Tracing bugs can sometimes be harder because the dependencies are injected, and it’s not always clear where they come from.
4. Performance Overhead: In some cases, DI can introduce a small performance overhead due to the creation and management of dependencies.
5. Overhead in Small Projects: For very small projects, the benefits of DI might not outweigh the complexity it introduces.

Conclusion

In summary, DI in Angular helps make code more modular, testable, and maintainable, but it can also introduce complexity and a learning curve for those new to the concept. It might be look a bit complex in the beginning but when you understand it and start to using it I bet you gonna love it. It is among the best features angular provides and very reason that I choose angular over other frontend frameworks. If you are interested in I share some links below so you can dig more and get to know more about Dependency Injection.

For examples you can also read the following post from angular guide!