Re: [Beacon] Data: Optional? Nullable?

On 2/11/14, 3:50 AM, Jonas Sicking wrote:
> On Mon, Feb 10, 2014 at 3:33 PM, Richard Barnes <> wrote:
>> Hey all,
>> I've been working on implementing Beacon in Firefox, and have had some
>> internal discussion with folks about the proper type for the "data"
>> parameter.
>> tl;dr: Data needs to be nullable and/or optional to avoid weird behavior.
>> The current ED has the following:
>> partial interface Navigator {
>>      boolean sendBeacon(DOMString url,
>>      (ArrayBufferView or Blob or DOMString or FormData) data);
>> };
>> That leads to behaviour that seems broken.  Since "DOMString" is included in
>> the list of allowed types, if the JS passes in null or undefined, it gets
>> converted to the string "null" or "undefined".
> This is quite normal JS behavior, so I wouldn't call it "broken".

"Broken" is maybe too strong.  Meant more that it was unexepceted to me 
as a developer, based on the spec.  But maybe that's just because I 
didn't properly understand the WebIDL :)

> However I would expect authors to be surprised that you have to send a
> body. Including all the data that the server cares about in the URL
> seems like a quite normal thing to do so I think it's something that
> we should allow.
> So I think we should make the argument nullable, let null mean "send
> no data" (and thus no Content-Type header), and make the argument
> optional and default to null.
>> So we've got two questions here:
>> 1. How should sendBeacon behave when data is null?
>> 2. How should sendBeacon behave when data is not provided?
> In both cases I think we should send no request body, but otherwise
> use normal behavior.

That sounds fine to me.

>> If we're going to send an empty request, then we probably shouldn't use
>> POST.
> Not having a request body for POST requests seems fully compliant with
> http 1.1. So I don't think we need to make any special exceptions
> here.

I can live with that.  I think it was Boris that told me he thought a 
POST with no body would be kind of weird, but I'll let him defend that 
position if he cares.


> / Jonas

Received on Tuesday, 11 February 2014 14:25:07 UTC