[RCTNetworking] Received data was invalid.

[PhilippKrone]

Hi,

since v0.7.0-rc.2, I get the following error:

 [error][tid:com.facebook.React.RCTNetworkingQueue][RCTNetworking.m:384] Received data was invalid.

When trying to fetch() something as follows:

 fetch('https://ssl.google-analytics.com/collect', {
 method: 'post',
 body: hit.toQueryString()
 });

This code was working in prior versions of RN. The return from google seems to be an empty gif (1x1px).

P.S. this is from react-native-google-analytics.

[PhilippKrone]

@brentvatne Do you have any idea here? I was now debugging for some hours but had no luck until now.

[PhilippKrone]

@nicklockwood I just figured it was your commit in RCTNetworking.m that introduced this check (f88bc3e) - do you have any idea as to why this might happen?

[nicklockwood]

We currently only support XHR requests that return text responses. Support for images is planned, but not currently implemented. It probably worked before because we didn't report the error and just returned null as the response.

[PhilippKrone]

@nicklockwood Thanks for the answer. Would it make sense to add it to the breaking changes section then? Moreover, wouldnt it be better to log the error but not create a redbox? Sometimes, you might just want to open an URL without parsing the result (as it is the case for google analytics sometimes).
@Iwansbrough This might be of interest for you in terms of react-native-google-analytics

[nicklockwood]

Yes, on both counts.

[PhilippKrone]

@brentvatne I've seen that you have been active concerning "breaking changes" recently IIRC. Are you able to add stuff there? Concerning the other point of changing:

 if (!responseText && data.length) {
 RCTLogError(@"Received data was invalid.");
 return;
 }

in RCTNetworking.m to something that does not result in a Redbox: could you gimme some guidance as to how this should be done in RN? Is it enough to change "RCTLogError" to "RCTLogWarn"? I would like to add a PR then (have never done that before, so a little more guidance is highly appreciated :))

[nicklockwood]

Hi Philipp, I'm just investigating what would be involved. If it was a normal method call you'd just return an error callback, but in this case it's slightly more complicated as you'd need to cancel the request to prevent multiple errors being sent.

[PhilippKrone]

@nicklockwood OK, I've just created a pull request to work with, feel free to give feedback in there if thats better.
#1860

[brentvatne]

Thanks for the heads up @PhilippKrone, I updated the breaking changes section of the release notes: https://github.com/facebook/react-native/releases/tag/v0.7.0-rc

[lwansbrough]

Thanks for looking into this guys, as @PhilippKrone said, this is affecting my GA module.

[lwansbrough]

Can we not just check the Content-Type of the response for any of text, json, xml, html? If one of those is contained in it, assume it's text, if it isn't then return the response as binary?

[negativetwelve]

I just updated to 0.7.0-rc.2 and started getting some response errors on the app that I'm creating. I submitted a pull request at #1917 that fixes a bug in the way response headers are looked up (values were supposed to be lowercased but ended up not being lowercased which caused looking up things like Content-Type to return null).

I'm not sure if this is going to fix your problem but since you said it was working prior to 0.7.0-rc.2 and my change fixes a bug introduced in this commit (e00b9ac) that was introduced in 0.7.0-rc.2, I figured you could try it out!