Should You Inject Dependencies into Attributes?

Attribute Dependency Injection: Challenges and Better Solutions

Injecting dependencies directly into attributes presents significant difficulties because the Common Language Runtime (CLR) manages their instantiation. This also applies to property injection, creating tight coupling and making the code brittle.

Such practices can interfere with dependency injection container verification, complicate framework caching mechanisms, and result in tightly coupled dependencies, increasing the likelihood of bugs.

Consequently, it's best to avoid dependency injection within attributes.

Superior Alternatives:

1. Passive Attributes (Separating Data and Behavior):

   • Decouple attribute metadata from its associated functionality.
   • Create a dedicated service to handle the logic and its dependencies.

2. Humble Objects (Logic Extraction):

   • Relocate all attribute logic to a custom service.
   • Register this service with the dependency injection container.
   • Utilize the attribute's methods as simple conduits to resolve and execute the service's methods.

Suggested Approach:

Option 1, separating data and behavior, generally leads to cleaner designs and broader applicability. However, Option 2 provides a more practical solution in certain contexts.

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