How Can I Pass Backend-Rendered Parameters to the Angular2 Bootstrap Method?

Passing Backend-Rendered Parameters to Angular2 Bootstrap Method

To pass arguments rendered on the backend to the Angular2 bootstrap method, leverage Angular's dependency injection capabilities. Here's how to achieve it:

var headers = ... // Retrieve headers from the server

bootstrap(AppComponent, [{ provide: 'headers', useValue: headers }]);

This approach allows you to inject these parameters into your Angular components or services:

class SomeComponentOrService {
   constructor(@Inject('headers') private headers) {}
}

Alternatively, you can directly provide prepared BaseRequestOptions as follows:

class MyRequestOptions extends BaseRequestOptions {
  constructor(private headers) {
    super();
  }
} 

var values = ... // Fetch headers from the server
var headers = new MyRequestOptions(values);

bootstrap(AppComponent, [{ provide: BaseRequestOptions, useValue: headers }]);

With this method, you can use these headers in your Angular application by injecting BaseRequestOptions directly:

class ConfigService {
  constructor(private http: Http, @Inject(BaseRequestOptions) private baseRequestOptions) { }
}

Note: For AoT compilation, move the factory closure outside of the class:

function loadContext(context: ContextService) {
  return () => context.load();
}

And within the NgModule:

@NgModule({
  ...
  providers: [ ..., ContextService, { provide: APP_INITIALIZER, useFactory: loadContext, deps: [ContextService], multi: true } ],

For cyclic dependency issues, inject the Injector and retrieve the dependency:

this.myDep = injector.get(MyDependency);

Instead of directly injecting `MyDependency`:

@Injectable()
export class ConfigService {
private router:Router;
constructor(/private router:Router/ injector:Injector) {

setTimeout(() => this.router = injector.get(Router));

}
}

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