How to handle errors from HTTP observables

Question

I am not sure how to handle http errors in an angular2 observable. What I have is

    getContextAddress() : Observable<string[]> {
        return this.http.get(this.patientContextProviderURL)
        .map((res:Response) => {
            return res.json()
        })
        .catch((error:any) => Observable.throw(error.json().error || 'Server error'));
}

in valid URL cases, i.e. response of 200, all is well. I am not sure why when I use a bad url, response code of 400, there is no error generate.

How do I handle that case?

What do you mean "there is no error generate"? Where do you subscribe to this? Do you provide the second error handling callback to the subscription? Have any logging in place to see what's happening? Please give a minimal reproducible example. — jonrsharpe
– jonrsharpe, Commented Apr 14, 2017 at 21:33

DeborahK · Accepted Answer · 2017-04-14 21:43:57Z

1

This code is simply re-throwing the error. Are you catching it somewhere?

For example, I have code like this:

this.productService.getProducts()
    .subscribe(products => this.products = products,
               error => this.errorMessage = <any>error);
}

This catches the thrown error and sets an errorMessage property that I then display in the UI.

answered Apr 14, 2017 at 21:43

DeborahK

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Comments

reza · Accepted Answer · 2017-04-14 23:09:02Z

0

I was not catching the error where the subscription was taking place. My mistake

answered Apr 14, 2017 at 23:09

reza

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