[DAS] next "feature" for 1.6 spec

[Jonathan Warren]

Thanks for all the great replies on this. I'm amazed at the different  
solutions people have come up with.

For now I suggest people have a play with the different suggestions  
and we can come back to this later this month and come up with a  
definitive solution.

Thanks

Jonathan.


On 29 Jun 2009, at 20:56, Ed wrote:

> I think this is a useful feature.  I think you should also consider  
> and test a variety of possible other syntax before making a  
> decision, though.
> One simple alternative is to add two new fields to the segment  
> element:
> <SEGMENT id="id" start="start" stop="stop" version="X.XX"  
> label="label" extendedStart="" extendedEnd="">
> Here extendedStart and extendedEnd refer to the start and end of the  
> maximum-sized region that you could have asked for which would have  
> returned the same set of features.
>
> Another simple alternative which requires NO new syntax would be for  
> the SEGMENT element to use the same format as before, but to allow  
> it to automatically stretch the start and end coordinates and return  
> them in the "start" and "end" fields.
>
> <SEGMENT id="id" start="extendedStart" stop="extendedStop"  
> version="X.XX" label="label">
> For example, if the user requests data for the region 1000 to 5000  
> but the response comes back as
>
> <SEGMENT id="id" start="500" stop="6100" version="X.XX" label="label">
> then the client would be able to know that there are no additional  
> features in the region from 500 to 6100.  Older clients would  
> probably not notice that the returned start and end were different  
> from the requested start and end and could work as before.
>
> Clients which cache results could cache this as covering the whole  
> region 500 to 6100 instead of just 1000 to 5000.
>
> I'm not currently involved in any DAS parsing, so I'm not likely to  
> stay in this discussion.  I just wanted to throw in this idea.
>
> Ed Erwin
> Affymetrix.
>
>
> 2009/6/29 Jonathan Warren <jw12 at sanger.ac.uk>
> Another feature we would like to add to the current 1.6 spec is the  
> ability for a server to return the next feature both left and right  
> of the current region if they exist but are out the currently  
> selected range.

Jonathan Warren
Senior Developer and DAS coordinator
jw12 at sanger.ac.uk
Ext: 2314
Telephone: 01223 492314








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