[DAS2] id, url, uri, and iri

Andrew Dalke dalke at dalkescientific.com
Mon Mar 13 14:29:28 UTC 2006

Something to settle.

I've been using 'id' like this

>  <FEATURE id = "feature/hit12"
>           type_id = "type/est-alignment"
>           created = "2001-12-15T22:43:36"
>           modified = "2004-09-26T21:10:15" >
>    <LOC id="residues/Chr3" range="1201:1400:1" />
>    <PART id="feature/hit12.hsp1" />
>    <PART id="feature/hit12.hsp2" />
>    <ALIGN target_id="feature/yk12391" range="200:299" />

As Dave Howorth pointed out, most people use 'id' as an
in-document identifier, and not as an identifier to link
to other documents.  Eg, there's a "getElementById()" method
in the DOM which is mean to find DOM nodes given the id.

In looking around I found that it's keyed off of the type
(as determined by the schema) and not by the string 'id'.
I added 'xml:id' as a possible DAS attribute, which is defined
by the XML spec to work as expected for getElementById.

In private email Gregg asked about using 'uri' instead of
'id' for this.

I'm now leaning that way.  Either 'uri' or 'url' or 'iri'.
I prefer url because everyone knows what that means.  Gregg
prefers 'uri' I think because that's what allows fragment
identifiers, and because it includes things which are other
than URLs, like LSIDs.

However, the latest thing these days is an "iri" which
means "internationalized resource identifier"

I haven't read enough of it to understand it.  My first
attempt says that it's okay to use "uri" because there
are 1-to-1 mappings between uris and iris.  Also, I don't
want to test bidirectional text and I suspect there isn't yet
widely used library support for iris.

So I want to change the DAS use of 'id' to 'url' and say
"the value of the 'url' attribute is a URI".

					dalke at dalkescientific.com

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