#10778: Standalone UUID implementation
----------------------------+-----------------------------------------------
Reporter: optilude | Owner: optilude
Type: PLIP | Status: new
Priority: minor | Milestone: 4.1
Component: Infrastructure | Resolution:
Keywords: |
----------------------------+-----------------------------------------------
Description changed by optilude:
Old description:
> = Motivation =
>
> Many applications require some notion of a universally unique ID. For
> example:
>
> * Archetypes/Kupu-style link-by-uid
> * References to content from non-content items, e.g. tiles/portlets
> * Disambiguation of content, e.g. in export/import scenarios
> * Effective tokenisation of content for vocabularies and selection
> widgets
>
> Archetypes has a solution its UID() attribute, but the implementation is
> AT-specific and rather heavyweight, requiring the interaction of three
> separate catalogues (portal_catalog, reference_catalog, uid_catalog).
>
> zope.intid/five.intid provide more generic integer ids, but these are not
> universally unique and so not stable across sites.
>
> CMFUId is a similar, CMF-specific solution.
>
> This PLIP proposes a lightweight, simple UUID mechanism that is
> independent of any content implementation. The aims are to have:
>
> * A standards-based UUID implementation, with
> * a simple, intuitive API, and
> * standard utility views
>
> = Assumptions =
>
> Plone wants to support content not exclusively built with Archetypes.
>
> = Proposal & Implementation =
>
> * A small package, ''plone.uuid'', with minimal dependencies
> * An adapter interface, ''IUUID'', to obtain a UUID for a content item.
> * A marker interface, 'IUUIDAware', which lets types opt into an on-
> create event handler, which allocates a UUID and stores it
> * All CMF content will be marked with this interface
> * UUIDs are generated using the standard library ''uuid'' module
> * The default implementation stores UUIDs in an attribute on the content
> object (an annotation would be less efficient, since it'd be in a
> separate persistent object)
> * Some utility views are registered:
> * ''@@uuid'', a view on any ''IUUIDAware'' item returning a UUID
> * ''@@resolve-uuid'', uses sub-path traversal to look up a UUID,
> returning a path
> * ''@@redirect-to-uuid'', uses sub-path traversal to look up a UUID,
> returning a 304 response
> * In addition, Plone should register a catalogue index and metadata
> column in ``portal_catalog`` to make it possibly to search by UUID and
> obtain a UUID from a catalogue brian
>
> = Deliverables =
>
> * The ''plone.uuid'' package
> * Minor changes to ''Products.CMFPlone''
> * A migration step to add UUIDs to existing content
> * Documentation
>
> = Risks =
>
> Potential confusion between this and the Archetypes' UID implementation.
>
> = Participants =
>
> Martin Aspeli, and hopefully others :-)
>
> = Progress =
>
> * PLIP submitted
New description:
= Motivation =
Many applications require some notion of a universally unique ID. For
example:
* Archetypes/Kupu-style link-by-uid
* References to content from non-content items, e.g. tiles/portlets
* Disambiguation of content, e.g. in export/import scenarios
* Effective tokenisation of content for vocabularies and selection
widgets
Archetypes has a solution its UID() attribute, but the implementation is
AT-specific and rather heavyweight, requiring the interaction of three
separate catalogues (portal_catalog, reference_catalog, uid_catalog).
zope.intid/five.intid provide more generic integer ids, but these are not
universally unique and so not stable across sites.
CMFUId is a similar, CMF-specific solution.
This PLIP proposes a lightweight, simple UUID mechanism that is
independent of any content implementation. The aims are to have:
* A standards-based UUID implementation, with
* a simple, intuitive API, and
* standard utility views
= Assumptions =
Plone wants to support content not exclusively built with Archetypes.
= Proposal & Implementation =
* A small package, ''plone.uuid'', with minimal dependencies
* A package ''plone.app.uuid'' for Zope 2/Plone specific stuff
* An adapter interface, ''IUUID'', to obtain a UUID for a content item.
* UUIDs are generated using the standard library ''uuid'' module
* A marker interface, 'IAttributeUUID', which lets types opt into an on-
create event handler, which allocates a UUID and stores it
* The default implementation stores UUIDs in an attribute on the content
object (an annotation would be less efficient, since it'd be in a separate
persistent object)
* Some utility views are registered:
* ''@@uuid'', a view on any ''IUUIDAware'' item returning a UUID
* ''@@redirect-to-uuid'', uses sub-path traversal to look up a UUID,
returning a 304 response
* Archetypes is updated to support the IUUID protocol and generate UUIDs
in the same way for new content (only). No migration will be required. The
UID() method will become a shim for IUUID(self). Code should be updated to
use IUUID instead if it needs to be compatible with non-AT content. It's
hoped that this can make it possible for AT content to make simple
references to non-AT content
= Deliverables =
* The ''plone.uuid'' and ''plone.app.uuid'' packages
* Updates to ''Products.Archetypes''
* Minor changes to ''Products.CMFPlone''
* Documentation
= Risks =
= Participants =
Martin Aspeli, and hopefully others :-)
= Progress =
* PLIP submitted
* PLIP implemented
* PLIP reviewed
--
--
Ticket URL: <http://dev.plone.org/plone/ticket/10778#comment:32>
Plone <http://plone.org>
Plone Content Management System
_______________________________________________
PLIP-Advisories mailing list
plip-advisor...@lists.plone.org
http://lists.plone.org/mailman/listinfo/plip-advisories
