Changes between Version 2 and Version 3 of ComponentVersioning

Timestamp:

04/10/12 11:46:34 (12 years ago)

Author:

twagoo

Comment:

design and implementation extended (xml examples)

ComponentVersioning

@@ -18 +18 @@
 The !ComponentRegistry web service (and as a result this will also apply to the Flex-based component browser) will not display deprecated components in any listing (e.g. [http://catalog.clarin.eu/ds/ComponentRegistry/rest/registry/profiles /registry/profiles]). However, they will still be available by their ID (like [http://catalog.clarin.eu/ds/ComponentRegistry/rest/registry/profiles/clarin.eu:cr1:p_1297242111880 /registry/profiles/clarin.eu:cr1:p_1297242111880]).
 
-There will be a call to list all direct (and possibly also recursive) successors
+There will be a call to list all direct (and possibly also recursive) successors of a specific component (see XML example below).
+
+Both the XML representation of a component and the XSD that results from the [source:/metadata/trunk/toolkit/xslt/comp2schema-v2/comp2schema.xsl comp2schema] transformation should contain deprecation and versioning information in some form (see below for a proposal).
 
 == Implementation ==
 
+=== Storage / internal representation ===
+
 The !ComponentRegistry web service has a PostgreSQL back-end in which it stores both the component specifications in their verbatim XML formatting and 'component metadata' (referred to as 'descriptions' to avoid ambiguity) containing fields such as 'creator' and 'group'. The 'deprecated' property can be added to this. To accommodate the successor relations, an additional table has to be added simply linking precursors and successors, and optionally storing a comment on each relation.
 
-{{{#!comment
+=== Client information ===
 
-Store in database
-Reflect in XSD
+Because most clients will consume the XSD transformation of components, the deprecation/versioning information will have to be represented in these profile schemata. It can be provided within an xs:appinfo element. This information can be taken from two proposed new ''optional'' header elements in the component specification: '''Deprecated''' and '''!SuccessorsList'''. 
 
-Relations:
-Deprecated yes/no & 0..* successors
+Example:
 
-Registry:
-Show only profiles/components that are not deprecated/replaced
+{{{
+#!xml
+<CMD_ComponentSpec isProfile="true">
+   <Header>
+      <ID>clarin.eu:cr1:p_1289827960126</ID>
+      <Name>LrtInventoryResource</Name>
+      <Description>Resources as stored before in the CLARIN LRT inventory</Description>
+      <Deprecated>true</Deprecated>
+      <SuccessorsList>http://catalog.clarin.eu/ds/ComponentRegistry/rest/registry/profiles/clarin.eu:cr1:p_1289827960126/successors</SuccessorsList>
+   </Header>
+}}}
 
-Get current successor=>follow successors
+in the XSD this would be transformed to:
+
+{{{
+#!xml
+<xs:schema xmlns:cmd="http://www.clarin.eu/cmd/"
+      xmlns:xs="http://www.w3.org/2001/XMLSchema"
+      xmlns:dcr="http://www.isocat.org/ns/dcr"
+      xmlns:ann="http://www.clarin.eu"
+      targetNamespace="http://www.clarin.eu/cmd/"
+      elementFormDefault="qualified">
+   <xs:import namespace="http://www.w3.org/XML/1998/namespace" schemaLocation="http://www.w3.org/2001/xml.xsd"/>
+   <xs:annotation>
+      <xs:appinfo>
+         <cmd:Deprecated>true</cmd:Deprecated>
+         <cmd:SuccessorsList>http://catalog.clarin.eu/ds/ComponentRegistry/rest/registry/profiles/clarin.eu:cr1:p_1289827960126/successors</cmd:SuccessorsList>
+      </xs:appinfo>
+   </xs:annotation>
 }}}
 
 == Discussion ==
 
-* Should we limit deprecation and versioning to published components?
+* Should we limit deprecation and versioning to published components? (what does it mean for an unpublished component to get deprecated?)
+* Should 'bi-directional' versioning information be provided or just successors? (should a successor component refer to its precursor?)
+* What to do with many-to-many relations in versioning? (merging and branching of components)