fix(AjaxObservable): support json responseType on IE

[kwonoj]

Description:
This PR updates internal behavior of AjaxObservable for IE specific by IE doesn't support json as response type, parse response as json object internally.

Related issue (if exists):

closes #1381

[kwonoj]

I'm not clear at the moment if this approach is legit & acceptable, send out as PR for discussion to close out issue. If it's expected to not to support those and let it be handled externally, I'll simply close this PR as well as issue.

/cc @trxcllnt also for visibility.

[benlesh]

Have we run this across all browsers? It seems legit on the surface.

[kwonoj]

I've ran over Chrome / IE, can check FF (but not able to verify on safari).

[kwonoj]

Yes, this logic itself works on FF as well. (noticed response is null actually, but this seems somewhat different issue - api itself, or somewhere else that need to triage separately)

[danmarshall]

the fallback '' should be 'null' instead. I will send a PR

[kwonoj]

@danmarshall , OK, then will wait PR instead of writing it up by my own.

[benlesh]

Merged with bba13d8. Thanks, @kwonoj

[danmarshall]

Cool fix @kwonoj - however I am seeing a specific issue when server replies with HTTP 204 - No Content.

When this code executes:

JSON.parse(xhr.response || xhr.responseText || '')

If xhr.response or xhr.responseText are null then the statement will parse the empty string.
JSON.parse('') throws a syntax error (in any browser). Fix would be to parse 'null' to create a null which is the response object for an HTTP 204 in non-IE browsers.

[kwonoj]

@danmarshall Thanks for suggestion. I'll try to come up with PR shortly.

[maximusdominus]

Not sure if this is the appropriate place to put this, but I Just encountered this bug in a different place: when the server returns JSON in a 4xx / 5xx response.

typeof(error.xhr.response) on IE is string, but on all other browsers it's an object

Here's what my code looks like

(action$, store) => action$
    .ofType(MY_TYPE)
    .switchMap( action =>
      Observable.ajax({
        url: 'myUrl',
        method: 'POST',
        body: action.options,
        responseType: 'json',
      })
      .map(...)
      .catch(error => Observable.of({type: FETCH_FAILURE, errorResponse: error.xhr.response})),
    )

[adepatie]

@maximusdominus Were you able to resolve this issue? I'm facing the same issue.

UPDATE: easiest workaround is to detect (typeof error.xhr.response === 'string') and use JSON.parse accordingly.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.