CODEWITHSUNDEEP
angularerror-handlingobservable
Mateusz Witkowski
Mateusz Witkowski

Reputation: 1746

Angular 2 error never get to custom error handler

I've got the simpliest implementation of Angular's (v2.4.3) custom error handler but still can't log errors. What can be wrong?

app.module.ts

providers: [
    { provide: ErrorHandler, useClass: MyErrorHandler }
]

my-error-handler.ts

import { ErrorHandler, Injectable} from '@angular/core';

@Injectable()
export class MyErrorHandler extends ErrorHandler {

  constructor(private errorHandlerService: ErrorHandlerService) {
    super();
  }

  public handleError(error: any): void {
    console.log('error'); // nothing
  }
}

sample-service.ts (trying to throw error)

  addSomething(data) {
    let bodyString = JSON.stringify(data);
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(this.url + 'expense', bodyString, options)
      .map((res: Response) => res.json())
      .catch(this.handleError);
  }

  private handleError(error: any) {
    console.log(error.json()); // error: { message: 'Some error' }

    return Observable.throw(error.json());
  }

Error throwed in service never get to MyErrorHandler. What could be wrong?

I don't know if that's important but in console I also got something like this:

POST http://path/to/api 422 // logged by zone.js

Upvotes: 1

Views: 3986

Answers (1)

coderek
coderek

Reputation: 1870

change 

export class MyErrorHandler extends ErrorHandler {

to 

export class MyErrorHandler implements ErrorHandler {

refer to here https://angular.io/docs/ts/latest/api/core/index/ErrorHandler-class.html

And you should also remove the .catch method that short-circuit the error handling

return this.http.post(this.url + 'expense', bodyString, options)
  .map((res: Response) => res.json())
  .catch(this.handleError);      // remove this method call

Upvotes: 7

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