...
Each of the query_uri attribute of the das1:feature CAPABILITY can be processed as one
feature (or several if there is a das1:types CAPABILITY) of a server, the server is the
uri before the first /.
(NOTE - at this point there must be some steps to restrict the features to ones that will
actually return data. Most of the features will fail for some reason, or return no data,
when queried.
For example, M_musculus_Jul_2007 will give four servers and
if you select and load all of the features, most will return data. But for A_thaliana_Jun_2009, five servers are found
and if you select and load the features, none of them will return data.)
If the user selects a feature, a new query can be processed, using the query_uri
attribute of the das1:feature CAPABILITY, and adding a (optional) type param, and a
(required) segment param. The segment param must contain the chromosome, and can contain
the start and end. See the DAS spec. For example:
http://gbrowse.informatics.jax.org/cgi-bin/das/mouse_current%7CQTL/features?segment=1
(NOTE - if you don't know the chromosome names - IGB calls them BioSeq and DAS calls them segment -
this can cause a problem. Most of the DAS servers seem to use 1 as opposed to chr1, etc. If the
server supports entry_points, this can be used, also the IGB synonyms file.)