I am currently working on an Angular app that communicates with an API. The JSON responses from the API are prefixed with )]}', as recommended in Angular's official documentation.
The issue I am facing is that my browser seems to try decoding the response before Angular does.
While debugging step by step, I noticed that right after the xhr.onload callback is fired, the response turns out to be null.
The specific code snippet causing the problem is this one:
// From angular.js(1.5.9):12122
xhr.onload = function requestLoaded() {
var statusText = xhr.statusText || '';
// responseText is the old-school way of retrieving response (supported by IE9)
// response/responseType properties were introduced in XHR Level2 spec (supported by IE10)
var response = ('response' in xhr) ? xhr.response : xhr.responseText;
// normalize IE9 bug (http://bugs.jquery.com/ticket/1450)
var status = xhr.status === 1223 ? 204 : xhr.status;
// fix status code when it is 0 (0 status is undocumented).
// Occurs when accessing file resources or on Android 4.1 stock browser
// while retrieving files from application cache.
if (status === 0) {
status = response ? 200 : urlResolve(url).protocol === 'file' ? 404 : 0;
}
completeRequest(callback,
status,
response,
xhr.getAllResponseHeaders(),
statusText);
};
}
xhr.response is null even before Angular processes anything (as far as I can tell).
Angular attempts to remove the prefix using the following code:
function defaultHttpResponseTransform(data, headers) {
if (isString(data)) {
// Strip json vulnerability protection prefix and trim whitespace
var tempData = data.replace(JSON_PROTECTION_PREFIX, '').trim();
if (tempData) {
var contentType = headers('Content-Type');
if ((contentType && (contentType.indexOf(APPLICATION_JSON) === 0)) || isJsonLike(tempData)) {
data = fromJson(tempData);
}
}
}
return data;
}
However, at this point, the data is never a string because the browser has already attempted to decode it (unsuccessfully).
The format of the API output is as follows:
)]}',
[{"name": "A"}, {"name": "B"}]
If I remove the prefix, everything works fine. I have tested this on Opera 45.0, Firefox 46, and Chrome 58, all of which exhibit similar behavior. Therefore, I believe I might be overlooking something crucial.
The response headers include:
HTTP/1.1 200 OK
Server: nginx/1.11.5
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Cache-Control: no-cache, private
[...]
Content-Length: 1793
Any insights would be greatly appreciated.
Thank you!