Inject service into an isolated ts file's function, outside of module in Nest Js v10

Inject service into an isolated ts file’s function, outside of module in Nest Js v10

If you are working with Nest Js v10 and trying to inject a service into an isolated TypeScript file’s function, outside of a module, you may face some challenges. In this blog post, we will explore different solutions to this problem.

Solution 1: Using the Nest Js Application Context

One way to inject a service into an isolated TypeScript file’s function is by using the Nest Js Application Context. The Application Context provides access to the Nest Js application instance and allows you to retrieve services from the container.

Here is an example of how you can use the Application Context to inject a service:


import { Injectable, NestApplicationContext } from '@nestjs/common';
import { MyService } from './my.service';

@Injectable()
export class MyFunctionService {
  private myService: MyService;

  constructor(appContext: NestApplicationContext) {
    this.myService = appContext.get(MyService);
  }

  public myFunction(): void {
    // Use the injected service here
    this.myService.doSomething();
  }
}

In the above example, we define a class called MyFunctionService and inject the NestApplicationContext into its constructor. We then retrieve the MyService from the application context using the get method. Now, we can use the injected service in the myFunction method.

Solution 2: Using the Dependency Injection Container

Another solution is to manually create an instance of the service using the dependency injection container provided by Nest Js.

Here is an example of how you can manually create an instance of a service:


import { Injectable } from '@nestjs/common';
import { MyService } from './my.service';

@Injectable()
export class MyFunctionService {
  private myService: MyService;

  constructor() {
    this.myService = new MyService();
  }

  public myFunction(): void {
    // Use the manually created service here
    this.myService.doSomething();
  }
}

In the above example, we create a new instance of the MyService using the new keyword in the constructor of the MyFunctionService class. Now, we can use the manually created service in the myFunction method.

Conclusion

Injecting a service into an isolated TypeScript file’s function, outside of a module, in Nest Js v10 can be achieved using the Nest Js Application Context or by manually creating an instance of the service using the dependency injection container. Choose the solution that best fits your needs and requirements.

Inject service into an isolated ts file’s function, outside of module in Nest Js v10