CODEWITHSUNDEEP
javascriptangularjsangular-http
hansmaad
hansmaad

Reputation: 18905

How to read JSON error response from $http if responseType is arraybuffer

I load some binary data using 

$http.post(url, data, { responseType: "arraybuffer" }).success(
            function (data) { /*  */ });

In case of an error, the server responds with an error JSON object like

{ "message" : "something went wrong!" }

Is there any way to get the error response in a different type than a success response?

$http.post(url, data, { responseType: "arraybuffer" })
  .success(function (data) { /*  */ })
  .error(function (data) { /* how to access data.message ??? */ })

Upvotes: 55

Views: 25081

Answers (3)

Adeel Imran
Adeel Imran

Reputation: 13966

Suppose in your service, you have a function you are using like, This is for Angular 2

someFunc (params) {
    let url = 'YOUR API LINK';
    let headers = new Headers();
    headers.append('Content-Type', 'application/json');
    headers.append('Authorization','Bearer ******');
    return this._http
            .post(url, JSON.stringify(body), { headers: headers})
            .map(res => res.json());    
}

Make sure when you return it it is res.json() and not res.json. Hope it helps, to anyone having this issue

Upvotes: 1

smkanadl
smkanadl

Reputation: 1067

Edit: As @Paul LeBeau points out, my answer assumes that the response is ASCII encoded.

Basically you just need to decode the ArrayBuffer into a string and use JSON.parse().

var decodedString = String.fromCharCode.apply(null, new Uint8Array(data));
var obj = JSON.parse(decodedString);
var message = obj['message'];

I ran tests in IE11 & Chrome and this works just fine.

Upvotes: 84

Paul LeBeau
Paul LeBeau

Reputation: 101868

@smkanadl's answer assumes that the response is ASCII. If your response is in another encoding, then that won't work.

Modern browsers (eg. FF and Chrome, but not IE yet) now support the TextDecoder interface that allows you to decode a string from an ArrayBuffer (via a DataView).

if ('TextDecoder' in window) {
  // Decode as UTF-8
  var dataView = new DataView(data);
  var decoder = new TextDecoder('utf8');
  var response = JSON.parse(decoder.decode(dataView));
} else {
  // Fallback decode as ASCII
  var decodedString = String.fromCharCode.apply(null, new Uint8Array(data));
  var response = JSON.parse(decodedString);
}

Upvotes: 29

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