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angularangular2-injection

Angular 2 injector can't find Service when loading CustomExceptionHandler


When trying to inject a service into my CustomExceptionHandler, the Angular injector cannot find the service.

The error: Uncaught Can't resolve all parameters for CustomExceptionHandler: (?).

The setup:

CustomExceptionHandler

import { ExceptionHandler } from '@angular/core';

import { ServiceA } from '../services/a.service';

export class CustomExceptionHandler extends ExceptionHandler {

  constructor(private serviceA: ServiceA) {
    super(null, null);
  }

  call(error, stackTrace = null, reason = null) {
      //do something with the service
  }
}

app.module

@NgModule({
  declarations: [
    ...
  ],
  imports: [
    ...
  ],
  providers: [
    ServiceA,
    { provide: ExceptionHandler, useClass: CustomExceptionHandler },
  ],
  bootstrap: [AppComponent],
})
export class AppModule { }

Solution

  • update ExceptionHandler was renamed to ErrorHandler https://stackoverflow.com/a/35239028/217408

    orgiginal

    Add @Injectable() to your CustomExceptionHandler class.

    Add CustomExceptionHandler as another one of your providers in the app.module.ts:

    @NgModule({
      declarations: [
        ...
      ],
      imports: [
        ...
      ],
      providers: [
        ServiceA,
        CustomExceptionHandler,
        { provide: ExceptionHandler, useClass: CustomExceptionHandler },
      ],
      bootstrap: [AppComponent],
    })
    export class AppModule { }