useValue

Using useValue in Providers

The useValue option allows you to register a fixed value or object as a dependency in the container. This is particularly useful for static configurations, constants, or objects that don’t need to be instantiated.

Example: Registering a Configuration Object

Suppose you have a configuration object for your application:

const AppConfig = {
  appName: "Depinjionary",
  version: "1.0.0",
  debug: true
};

You can register it as a provider using useValue:

import { ContainerResolver } from "depinjionary";

const providers = [
  { provide: "AppConfig", useValue: AppConfig }
];

const container = ContainerResolver.init(providers);

const config = await container.resolve<{ appName: string, debug: boolean }>("AppConfig");
console.log(config.appName); // Outputs: "Depinjionary"
console.log(config.debug);   // Outputs: true

---

Example: Using useValue for Constants

If you need to register a simple constant, useValue is also a great choice:

const API_ENDPOINT = "https://api.example.com";

const providers = [
  { provide: "ApiEndpoint", useValue: API_ENDPOINT }
];

const container = ContainerResolver.init(providers);

const endpoint = await container.resolve<string>("ApiEndpoint");
console.log(endpoint); // Outputs: "https://api.example.com"

---

Key Notes

1. When to Use useValue:

   • For static data like configurations, constants, or shared objects.
   • When no instantiation logic is required.

2. Accessing Values:

   • Use the provide key as the token to retrieve the value from the container.

3. Best Practices:

   • Use descriptive tokens (e.g., "AppConfig", "ApiEndpoint") to avoid confusion.
   • Combine with other types of providers (useClass, useFactory) for a well-structured dependency setup.

---