[DAS] Dalliance: a new genome DAS client

[Thomas Down]

On Wed, Aug 4, 2010 at 3:53 PM, Andy Jenkinson <andy.jenkinson at ebi.ac.uk>wrote:

> Sure:
> http://www.ebi.ac.uk/das-srv/genomicdas/das/sources
>
> The implementation in ProServer is a bit more advanced in that it deals
> with preflight (HTTP "options") requests. These are necessary if the client
> sends custom headers (err, like X-DAS-Client in DAS 1.6) and non-simple
> requests (such as PUT). Cross-origin writeback would require preflight
> request support, for example.
>
> By the way, I just looked at the CORS spec and have made some changes to
> ProServer's implementation to support the 'expose headers' portion of the
> spec. Either this wasn't there last year or I missed it. I think this is
> necessary before the browser will get access to the custom DAS headers such
> as X-DAS-Status.
>

Yes, Access-Control-Expose-Headers is a new addition in the latest draft --
and, as you say, kind-of useful for DAS (specifically: we'll be able to
implement zooming rather more efficiently in Dalliance once we can detect
which sources actually implement maxbins -- which is currently a problem).

Unfortunately, the client support for this bit isn't there yet (see, for
instance, https://bugs.webkit.org/show_bug.cgi?id=41210), but will hopefully
appear soon!

                Thomas.