TITLE: InterService links in DAS/2 Author: Ewan Birney Date: 14 August 2001 To allow richer programmatic access in DAS/2 there should be the necessary hooks to allow one data type to point out to other data types held in other databases, usually in other data formats (but probably XML). This hook would be the equivalent of the href hook used by humans to get more data. The hook in my mind needs 3 elements (1) The identifier of the object it wants to point to in the other service (this may not be the same as the identifier of the object in the current data document) (2) A service where to retrieve that object and/or a meta-description of that service if one expects clients to prefer to negotiate to a local service provider (something like a URI and/or a SOAP service locator thing) (3) The XML schema/DTD of what is delivered back by that service so that the client can at least determine whether it wants to haul the data back out ie, something like A use case would be to indicate that this gene (identified in a simple DAS-GFF form as a start-end on genomic coordinates) has a particular expression pattern as indicated an identifier to the ArrayDescription level in, say, ArrayExpress, a service locator of ArrayExpress and a indicator that this in MIAMI format. These hooks should both be bundled by data serving services (like the current DAS-1 genome features) and also able to be retrieved from registry services allowing third parties to say, hook into Ensembl gene identifiers without altering Ensembl's DAS server itself. Something similar to the CORBA Trading service (in concept - not in implementation!) could then be added to provide a generic ranked list for a client who says "I have this information [ensembl gene] and I want this information [expression data]" but I would be more than happy to defer this to DAS/3 or indeed punt on it completely. The main thing is to provide a programmatic equivalent of the href outlink system ----------------------------------------------------------------- Ewan Birney. Mobile: +44 (0)7970 151230, Work: +44 1223 494420 . -----------------------------------------------------------------