Re: JSON headers

[Willy Tarreau <[e-mail]>]

On Mon, Jul 11, 2016 at 03:47:32PM -0400, Yanick Rochon wrote:
> On 11 July 2016 at 15:25, Willy Tarreau <[e-mail]> wrote:
> 
> > On Mon, Jul 11, 2016 at 09:11:09PM +0200, Julian Reschke wrote:
> >
> > OK thanks for explaining. But then what situation could lead to this
> > confusing object to be emitted ? I thought that it was only related to
> > posting multiple headers in which case I don't see the issue if we
> > consider that all these headers are lists, and are then concatenated
> > by the recipient.
> >
> >
> If, for example, a sender sends a request such as
> 
> { ..., "Accept":
> "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5",
> ..., "Accept": "text/plain;q=0.9", ... }
> 
> through a clumsy string concatenation, what is the suggested behavior?

For me it means it sent two values for the Accept header defined as a list,
the first one being "appliation/xml...", and the second one "text/plain...".

I'm having an issue with the representation above though (and maybe I missed
certain things recently), because my understanding of JSON headers till now
was that one would send :

   { "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5" }

as the value of the first Accept header field, then

   { "text/plain;q=0.9" }

as the value of the second Accept header field.

And it's the recipient which would then decide to make a list of it because
we'd specifiy that each JSON-encoded header is a clearly defined list, so on
first header received it would do something like this (I'm not 100% sure about
the syntax as I'm not good at JSON) :

   { "Accept": {
        "application/xml", "application/xhtml+xml", "text/html;q=0.9",
        "text/plain;q=0.8", "image/png", "*/*;q=0.5" } }

Then when receiving the second header, it would simply append its value to
the list :

   { "Accept": {
        "application/xml", "application/xhtml+xml", "text/html;q=0.9",
        "text/plain;q=0.8", "image/png", "*/*;q=0.5", "text/plain;q=0.9" } }

Since it seams easy to me I'm having an issue understanding the deeper
problem and am pretty sure I missed something :-/

Regards,
Willy