Should You Use Dependency Injection in Attributes?

Dependency Injection in Properties: A Deep Dive

Injecting dependencies in properties has always been a topic of discussion among developers due to the potential problems it can bring. To understand these issues, let's explore the technical limitations and shortcomings of this approach.

Challenges of Property Dependency Injection

Constructor injection (passing dependencies into the constructor during object creation) is not possible for properties because the common language runtime (CLR) controls the instantiation of properties. Property injection, as an alternative, suffers from temporal coupling issues and makes it difficult to verify container configurations.

An alternative to property dependency injection

To avoid the pitfalls of property dependency injection, there are two main approaches to consider:

1. Separate attributes and behaviors

This technology separates passive data (properties) from active behavior (services). Services contain dependencies and business logic, while properties are responsible for resolving the service and delegating operations to it.

2. Simple objects

This approach involves extracting all the logic from the properties and creating a service that encapsulates the dependencies. Property methods delegate tasks to services, using a service locator or DependencyResolver to dynamically retrieve service instances. However, direct injection and storage of services in property fields is not supported.

Choose an alternative

The choice of alternatives depends on specific needs and design preferences:

• Option 1 is appropriate when design simplicity is important or when properties are applied across multiple assemblies.
• Option 2 is recommended when simplicity is a priority.

In summary, using dependency injection in properties should be treated with caution. By understanding the limitations and adopting alternatives such as detaching properties and creating concise objects, developers can avoid potential problems and maintain a robust and easy-to-maintain code base.

The above is the detailed content of Should You Use Dependency Injection in Attributes?. For more information, please follow other related articles on the PHP Chinese website!