[
https://issues.apache.org/jira/browse/JCR-2011?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12680837#action_12680837
]
Charles Brooking commented on JCR-2011:
---------------------------------------
When you say "'semantic change' refers to node types with special semantics
(e.g. mix:versionable)", do you have a reference for this? I'd be interested in
finding out what the spec actually means.
It says
"the semantic change in effective node type
and the persistence of the change to the jcr:mixinTypes property
occur on save",
so surely this encompasses the change in effective node type! My interpretation
of the phrase "semantic change" is that it just distinguishes the meaningful
effects of changing types from the "literal change", which is the setting of
the jcr:mixinTypes attribute.
So my (humble) interpretation is that if the change in effective node type
should be persisted on save, then this issue is valid. Say I remove one mixin
type that includes a "foo" property but add another mixin type including an
identical "foo" property. If I do both of these things before saving, then the
"semantic change in effective node type" would be nil.
By the way, the spec for Node.setPrimaryType(String) also says: "Semantically,
the new node type may take effect immediately and must take effect on save.
Whichever behavior is adopted it must be the same as the behavior adopted for
addMixin() and the behavior that occurs when a node is first created." (section
5.5.3) This may mean that add/removeMixin should happen on save (thus
collectively being atomic like setPrimaryType), and maybe this is a bug rather
than improvement?
Some discussion on the list would be good, because I'm no JCR expert.
> Replacing mixin type doesn't preserve properties
> ------------------------------------------------
>
> Key: JCR-2011
> URL: https://issues.apache.org/jira/browse/JCR-2011
> Project: Jackrabbit Content Repository
> Issue Type: Improvement
> Components: jackrabbit-core
> Reporter: Charles Brooking
> Priority: Minor
>
> NodeImpl.setPrimaryType(String) attempts to "redefine" nodes and properties
> that were defined by the previous node type if they also appear in the new
> type. If there is no matching definition for a node/property in the new type
> - or value conversion for matched node/property fails - only then are
> children removed. For example, say I have a node "harry", with a primary type
> "Human" that defines a "bloodgroup" property. If I set the primary type to be
> an unrelated type "Animal" that has a similar "bloodgroup" property, then its
> property value will survive the call to setPrimaryType("Animal").
> The same is apparently not possible with mixins. NodeImpl.removeMixin(Name)
> immediately removes all children that were defined by the mixin (strictly,
> those that are not present in the effective node type resulting from the
> mixin being removed). In addition, NodeImpl.addMixin(Name) immediately throws
> a NodeTypeConflictException if you attempt to add a mixin defining an
> identically-named property prior to calling removeMixin. For example, say I
> have a node "matrix", with a mixin type "movie" that defines a "title"
> property. If I wish to replace the "movie" mixin on that node with another
> "jcr:title" mixin type, the existing "title" property will be deleted.
> This occurs regardless of the order in which removeMixin and addMixin are
> called, and without session.save() being called between them. One option for
> coding this is to defer validation (and possible node/property removal) until
> session.save() is called.
> This is not strictly a bug, as JSR-283 seems to leave the details of
> assigning node types (section 5.5) unspecified. However, it does say for
> Node.removeMixin(String) that "Both the semantic change in effective node
> type and the persistence of the
> change to the jcr:mixinTypes property occur on save" and ideally we could
> emulate the nice behaviour in NodeImpl.setPrimaryType(String) for mixin types.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
