[occi-wg] Syntax for attributes on links

[Richard Davies]

Following up the topic of attributes on links after the discussion on our
call:


The original example was:

> <link href="urn:uuid:4cc8cf62-69a4-4650-9e8c-7d4c516884df"
>       rel="http://purl.org/occi/storage#device" title="Hard Drive"/>

And as I said before, we also need a device identifier at which to connect
the storage, making it something like:

> <link type="ide:0:0" href="urn:uuid:4cc8cf62-69a4-4650-9e8c-7d4c516884df"
>       rel="http://purl.org/occi/storage#device" title="Hard Drive"/>

which mapped to JSON as:

> "link":[
>   {
>     "type":"ide:0:0"
>     "rel":"http://purl.org/occi/storage#device",
>     "href":"urn:uuid:4cc8cf62-69a4-4650-9e8c-7d4c516884df",
>     "title":"Hard Drive"
>   }
> ]


I still believe that the "link" here is a figment of conversion from the
Atom XML format. To write this in something more like native JSON, I'd go
with:

"ide:0:0": {
  "href":"urn:uuid:4cc8cf62-69a4-4650-9e8c-7d4c516884df",
  "title":"Hard Drive"
}

since the device identifier is unique for the VM, and clearly specifies this
as a place where storage is being attached.



In text format, I'd flatten this data structure as:

ide:0:0|href|4cc8cf62-69a4-4650-9e8c-7d4c516884df
ide:0:0|title|Hard Drive

or even just:

ide:0:0|4cc8cf62-69a4-4650-9e8c-7d4c516884df
ide:0:0|title|Hard Drive

Rather than the original:

link|ide:0:0|http://purl.org/occi/storage#device|Hard Drive|urn:uuid:4cc8cf62-69a4-4650-9e8c-7d4c516884df


This is rather cleaner in terms of not having to know what all the possible
attributes might be, and where they appear in the |-deliminated list.

Cheers,

Richard.