Changes between Initial Version and Version 1 of UUID

Timestamp:

05/04/10 22:39:14 (15 years ago)

Author:

Dominic König

Comment:

--

UUID

@@ +1 @@
+[[TOC]]
+= UUID conventions =
+
+== General ==
+
+UUIDs (Universal Unique IDentifiers) in Eden follow the Python uuid implementation,
+which is specified in RFC4122:
+
+    http://www.faqs.org/rfcs/rfc4122.html
+
+However, other systems do not necessarily follow this convention (especially data sets
+outside of IT systems), but we still must be able to identify such data resources.
+
+Therefore, in every shared resource (XML+JSON), the UUID shall be prefixed by the domain
+name of the originating instance (authoritative domain) plus a slash ("/"), e.g.
+
+{{{
+    haiti.sahanafoundation.org/12345678-1234-5678-1234-567812345678
+}}}
+
+Generally, a "domain name" here can be any arbitraty XML name except it must not contain
+any slashes. However, the domain name must be unique, of course - and therefore it is
+recommended to use the internet domain name of the current instance. This in turn requires
+that all applications which share that domain name and take part in the data exchange adhere
+to the same UUID convention (UUID's have to be unique at least within the same domain).
+
+== Implementation Guideline ==
+
+At '''import''', when the system receives a resource with a prefixed UUID and the prefix matches
+the domain of the current instance, then the prefix gets removed to identify the resource
+in the database. If the prefix differs from our domain, then the prefix is retained in the
+database record.
+
+At '''export''', all unprefixed UUIDs from the database get prefixed by the domain name of the
+current instance. In those UUIDs which already have a prefix (because they have been imported
+from another domain), the prefix is retained.
+