What is the process for exporting services within a module?

Is there a way to export a service from a module in angular 2?

I am looking to import the service into another component without specifying the exact location of the service. I believe it should be the responsibility of the module to handle this.

Core.module.ts:

import {
NgModule,
Optional, SkipSelf } from '@angular/core';
import { CommonModule } from '@angular/common';

import { MyApi } from './Api/myApi.service';

import { AuthenticationModule } from './authentication/authentication.module';

@NgModule({
imports: [
    CommonModule,
    AuthenticationModule
],
providers: [
    MyApi
],
exports: [MyApi, AuthenticationModule]
})
export class CoreModule {
constructor( @Optional() @SkipSelf() parentModule: CoreModule) {
    if (parentModule) {
    throw new Error(
        'CoreModule is already loaded. Import it in the AppModule only');
    }
}

}

App.component.ts:

import { Router, ActivatedRoute } from '@angular/router';
import { Component, ViewContainerRef, OnInit } from '@angular/core';

import { MyApi } from 'core.module'; //i want this to be the core module import, not './core/api/myApi.service'

@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
    constructor ( public service: MyApi) {
        service.doStuff()
    }
}

However, when I try to implement the above code, it indicates that MyApi is not exported by Core.module.

Note that this code snippet is slightly pseudo-code, so please pardon any minor mistakes I may have made :)

Answer №1

If you're looking to streamline your import statements, here are a couple of techniques you can implement:

  1. One approach is to export all components from your main file (usually named index.ts) and then import them individually as needed:

    import { NgModule } from '@angular/core';
    import { ApiService } from 'path/to/api.service';
    @NgModule({ ... })
    export class CoreModule {}
    export * from 'path/to/api.service';
    

    This allows you to import both CoreModule and ApiService from a single source like this:

    import { CoreModule, ApiService } from 'path/to/core.module;'
    

    Creating a central entry point for your module dependencies.

  2. In cases where your module is deeply nested or requires importing from a complex directory structure, consider defining an alias in your main tsconfig.json file, within compilerOptions.paths:

    {
      "compilerOptions": {
        // ...
        "paths": {
          "@app-core": ["app/path/to/deeply/nested/core.module"]
        }
      }
    }
    

    Then utilize this alias in your import statements:

    import { CoreModule, ApiService } from '@app-core'
    

Answer №2

Make sure to include the following line in your core.module

export {MyApi} from './Api/myApi.service';

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