Provide a CORS+POST transport

[mattrobenolt]

This is to go with getsentry/sentry#2267

I assume we'd instruct this through Raven.setTransport(Raven.POST) or something similar as an opt-in for the short term.

And likely plan on that being the default in 2.0 and bail on the GET/Image magic.

[dcramer]

IMO just "useCors: true" (or opt-out if we are assuming it works everywhere) Clients dont auto update anyways so should be safe.

[mattrobenolt]

We can do that too. It doesn't matter to me what the interface is.

[benvinegar]

How about this. You can either use the callback method setTransport, or you can use the transport config key, which accepts either an object or a string keyword.

e.g.

Raven.config({
  transport: 'xhr-post'
}).install();

or

Raven.config({
  transport: Raven.POST // or XhrPost or XHRPost
}).install();

I think XHR and POST are more important keywords than CORS.

[dcramer]

IMO we do not need flexibility on transports.

There are two situations:

1. You use your builtin transport mechanism
2. You specify a different way to upload data

The primary reason of the current flexibility is because we're not sure CORS is safe, right? So why dont we just focus on making that opt-in (or better yet, opt-out) until we're ready for it to be the only transport mechanism we bake in. We can still provide a hook for "how do I send data" but we dont need a complex API for that. Ruby does it via an 'async' option which you specify the calling function.

[mattrobenolt]

Ok, so to summarize our conversation: We don't want to expose a massive public API (or any public API) at all to suggest that there are a ton of different random transport options.

I also think it's slightly misleading to expose a random option useCORS. 1, because it's the wrong word. 2, because if we plan on making this the default, it'll go away soon after. So I'd rather not expose a public API at all for configuring this.

I'd like to see a function that does the transport with no public API that we can test ourselves internally before committing to it being public for the world.

Does this summarize well?

[dcramer]

I think thats correct. If it wasn't clear I'm not proposing we remove a public function to override how we send data.

[mattrobenolt]

@benvinegar I just tested locally by repurposing your react-native plugin:

function xhrTransport(options) {
    var request = new XMLHttpRequest();
    request.onreadystatechange = function (e) {
        if (request.readyState !== 4) {
            return;
        }

        if (request.status === 200) {
            if (options.onSuccess) {
                options.onSuccess();
            }
        } else {
            if (options.onError) {
                options.onError();
            }
        }
    };

    request.open('POST', options.url + '?' + urlencode(options.auth));
    request.send(JSON.stringify(options.data));
}

And this worked fine in Chrome now. I'm sure we'll need to do work to detect if this is able to be done, and to use the appropriate API depending on the browser. Like the examples in here: http://www.html5rocks.com/en/tutorials/cors/