Category: Registration

In Parsley, the fundamental way to register services is by providing a constructor function to the service registry. This method enables you to create instances of your services in a controlled manner and inject them into your application as needed.

In Parsley, the RegisterInstance method registers a preexisting service instance, particularly useful for objects that cannot be created automatically due to complex configuration, data dependencies, or third-party APIs. Once registered, these instances behave as singletons, meaning the same instance is reused throughout the application. This ensures the registered object is consistently available as a dependency for other services, maintaining consistency and state across your application.

In Parsley, you can register a factory function to provide more control and customization when creating service instances. A factory function differs from a constructor function because it allows you to pass additional parameters to configure the service creation process.

In Parsley, you can register services with specific names to support more granular control and flexible resolution of service instances. Named services are beneficial when you need to manage multiple implementations of the same interface or provide different configurations for different contexts.

Parsley supports registering multiple services under the same contract type, allowing you to inject a list of these services into your application. While you can always resolve multiple services of the same contract using the ResolveRequiredServices[T] method, injecting them as an array or slice requires a list registration via the RegisterList[T] method.

Parsley provides a convenient way to group related services into modules using the RegisterModule method. This method allows you to register a function that bundles service registrations, making your code more organized and maintainable. Here's how to use it:

Parsley allows you to control the lifetime of your service instances through different lifetime scopes. The lifetime setting determines how often the constructor or factory method of a service registration is called and how instances are managed.

Parsley supports lazy proxies, a powerful feature that allows for the delayed activation of services. A lazy proxy acts as a placeholder for a dependency, deferring its creation until it is needed. This is particularly useful for services that are expensive to create or may not always be required immediately.

Parsley provides a Validator service to improve service registration and dependency management by detecting two key issues: missing dependencies and circular dependencies. These configuration issues can be challenging, but the Validator ensures your application's dependency graph is valid. It is an essential tool for enhancing the robustness of service registration and resolution, especially in applications with complex service interactions.

The Parsley CLI introduces a powerful feature for advanced dependency injection through its generate proxy command. This command, combined with //go:generate annotations, automatically generates proxy services and interfaces for your service contracts.