diff --git a/content/components.md b/content/components.md index 52cac155a2..89e4625db8 100644 --- a/content/components.md +++ b/content/components.md @@ -4,9 +4,9 @@ Providers are a fundamental concept in Nest. Many of the basic Nest classes may
-In the previous chapter, we built a simple `CatsController`. Controllers should handle HTTP requests and delegate more complex tasks to **providers**. Providers are plain JavaScript classes that are declared as `providers` in a [module](/modules). +In the previous chapter, we built a simple `CatsController`. Controllers should handle HTTP requests and delegate more complex tasks to **providers**. Providers are plain JavaScript classes that are declared as `providers` in a NestJS module. For more information, refer to the NestJS Module documentation. -> info **Hint** Since Nest enables the possibility to design and organize dependencies in a more OO way, we strongly recommend following the [SOLID](https://en.wikipedia.org/wiki/SOLID) principles. +> info **Hint** Since Nest enables the possibility to design and organize dependencies in a more OO way, we strongly recommend following the [SOLID principles](https://en.wikipedia.org/wiki/SOLID). #### Services @@ -112,7 +112,7 @@ The `CatsService` is **injected** through the class constructor. Notice the use #### Dependency injection -Nest is built around the strong design pattern commonly known as **Dependency injection**. We recommend reading a great article about this concept in the official [Angular](https://angular.dev/guide/di) documentation. +Nest is built around the strong design pattern commonly known as **Dependency injection**. We recommend reading a great article about this concept in the official [Angular documentation](https://angular.dev/guide/di). In Nest, thanks to TypeScript capabilities, it's extremely easy to manage dependencies because they are resolved just by type. In the example below, Nest will resolve the `catsService` by creating and returning an instance of `CatsService` (or, in the normal case of a singleton, returning the existing instance if it has already been requested elsewhere). This dependency is resolved and passed to your controller's constructor (or assigned to the indicated property): @@ -122,13 +122,13 @@ constructor(private catsService: CatsService) {} #### Scopes -Providers normally have a lifetime ("scope") synchronized with the application lifecycle. When the application is bootstrapped, every dependency must be resolved, and therefore every provider has to be instantiated. Similarly, when the application shuts down, each provider will be destroyed. However, there are ways to make your provider lifetime **request-scoped** as well. You can read more about these techniques [here](/fundamentals/injection-scopes). +Providers normally have a lifetime ("scope") synchronized with the application lifecycle. When the application is bootstrapped, every dependency must be resolved, and therefore every provider has to be instantiated. Similarly, when the application shuts down, each provider will be destroyed. However, there are ways to make your provider lifetime **request-scoped** as well. You can read more about these techniques in the [Injection Scopes documentation](/fundamentals/injection-scopes). #### Custom providers -Nest has a built-in inversion of control ("IoC") container that resolves relationships between providers. This feature underlies the dependency injection feature described above, but is in fact far more powerful than what we've described so far. There are several ways to define a provider: you can use plain values, classes, and either asynchronous or synchronous factories. More examples are provided [here](/fundamentals/dependency-injection). +Nest has a built-in inversion of control ("IoC") container that resolves relationships between providers. This feature underlies the dependency injection feature described above, but is in fact far more powerful than what we've described so far. There are several ways to define a provider: you can use plain values, classes, and either asynchronous or synchronous factories. More examples of defining providers can be found in the [Dependency Injection documentation](/fundamentals/dependency-injection). #### Optional providers @@ -145,7 +145,7 @@ export class HttpService { } ``` -Note that in the example above we are using a custom provider, which is the reason we include the `HTTP_OPTIONS` custom **token**. Previous examples showed constructor-based injection indicating a dependency through a class in the constructor. Read more about custom providers and their associated tokens [here](/fundamentals/custom-providers). +Note that in the example above we are using a custom provider, which is the reason we include the `HTTP_OPTIONS` custom **token**. Previous examples showed constructor-based injection indicating a dependency through a class in the constructor. You can read more about custom providers and their associated tokens in the [Custom Providers documentation](/fundamentals/custom-providers). #### Property-based injection