|Version 4 (modified by 13 years ago) ( diff ),|
UUIDs (Universal Unique IDentifiers) in Eden follow the Python uuid implementation, which is specified in RFC4122:
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.
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).
This convention is adopted from the person_record_id convention of PFIF.
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.