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Posted to dev@openjpa.apache.org by Kevin Sutter <kw...@gmail.com> on 2007/01/17 00:20:58 UTC

Processing "system level" entity listeners

Looking for some assistance (that is, background information) on how the
orm.xml parsing is supposed to work.  I'm attempting to specify some entity
listeners in my orm.xml, but I continue to get the following TRACE message:

322664  my persistence unit  TRACE  [main] openjpa.MetaData - OpenJPA does
not currently support XML element "pre-persist". Ignoring.

My orm.xml looks like this:

<entity-mappings
    xmlns="http://java.sun.com/xml/ns/persistence/orm"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm
http://java.sun.com/xml/ns/persistence/orm_1_0.xsd"
    version="1.0">
    <persistence-unit-metadata>
        <persistence-unit-defaults>
            <entity-listeners>
                <entity-listener class="
com.ibm.ws.persistence.tests.simple.TestEntity">
                    <pre-persist  method-name="prePersist" />
                    <post-persist method-name="postPersist" />
                    <pre-remove   method-name="preRemove" />
                    <post-remove  method-name="postRemove" />
                    <pre-update   method-name="preUpdate" />
                    <post-update  method-name="postUpdate" />
                    <post-load    method-name="postLoad" />
                </entity-listener>
            </entity-listeners>
        </persistence-unit-defaults>
    </persistence-unit-metadata>
</entity-mappings>

I've started to debug this problem, but I have some general questions on how
the SAX parser is supposed to work.  I see in the
CFMetaDataParser.startElement() where these "entity-listener" related tags
are treated as System Elements -- we end up calling
XMLPersistenceMetaDataParser.startSystemElement().

The processing in this method is dependent on whether the given element is a
MetaDataTag or not.  When we process the "entity-listener" element, it's
treated like a "normal" element and we fall past the switch statement and
eventually call startEntityListener().  This processing all seems to depend
on whether the _elems hashmap contains a string entry or a MetatDataTag for
a given Element.  What is the significance of being a MetaDataTag or not?

In this simple orm.xml, I have noticed that persistence-unit-metadata,
persistence-unit-defaults, and entity-listener are not MetaDataTags.  But,
entity-listeners and the individual pre-persist, post-persist, etc elements
are all MetaDataTags.

When one of these pre-* or post-* MetaDataTag elements are processed in the
startSystemElement() method, we fall into the default leg of the switch
statement and produce the TRACE message outlined above.

Any pointers would be appreciated.  Thanks!

Kevin

Re: Processing "system level" entity listeners

Posted by Kevin Sutter <kw...@gmail.com>.
Marc,
Thanks for the background on the earlier drafts of the JPA spec.  That helps
explain some of the processing that I see.  I also now see that elements
tagged as MetaDataTags have corresponding annotation support associated with
them.  So, it looks like I just need to provide similar callback processing
for the pre-* and post-* methods at the "system" level as exist at the
"class" levels.  Thanks for your insights.

Kevin

On 1/16/07, Marc Prud'hommeaux <mp...@apache.org> wrote:
>
> Kevin-
>
> The draft of the JPA spec said that "pre-persist" was only supported
> beneath the "entity-listeners" (note plural) element, rather than
> "entity-listener". This appears to have been corrected in the final
> version of the spec, but it looks like we never updated that part of
> the code (and the CTS doesn't test for it). This is indeed a bug.
>
> As for how the parser works, I'm afraid I don't know all that much
> about it (aside from sharing your observation that it is complex).
> Hopefully, though, my comment above will make the problem make a
> little more sense to you...
>
>
>
> On Jan 16, 2007, at 3:20 PM, Kevin Sutter wrote:
>
> > Looking for some assistance (that is, background information) on
> > how the
> > orm.xml parsing is supposed to work.  I'm attempting to specify
> > some entity
> > listeners in my orm.xml, but I continue to get the following TRACE
> > message:
> >
> > 322664  my persistence unit  TRACE  [main] openjpa.MetaData -
> > OpenJPA does
> > not currently support XML element "pre-persist". Ignoring.
> >
> > My orm.xml looks like this:
> >
> > <entity-mappings
> >    xmlns="http://java.sun.com/xml/ns/persistence/orm"
> >    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> >    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm
> > http://java.sun.com/xml/ns/persistence/orm_1_0.xsd"
> >    version="1.0">
> >    <persistence-unit-metadata>
> >        <persistence-unit-defaults>
> >            <entity-listeners>
> >                <entity-listener class="
> > com.ibm.ws.persistence.tests.simple.TestEntity">
> >                    <pre-persist  method-name="prePersist" />
> >                    <post-persist method-name="postPersist" />
> >                    <pre-remove   method-name="preRemove" />
> >                    <post-remove  method-name="postRemove" />
> >                    <pre-update   method-name="preUpdate" />
> >                    <post-update  method-name="postUpdate" />
> >                    <post-load    method-name="postLoad" />
> >                </entity-listener>
> >            </entity-listeners>
> >        </persistence-unit-defaults>
> >    </persistence-unit-metadata>
> > </entity-mappings>
> >
> > I've started to debug this problem, but I have some general
> > questions on how
> > the SAX parser is supposed to work.  I see in the
> > CFMetaDataParser.startElement() where these "entity-listener"
> > related tags
> > are treated as System Elements -- we end up calling
> > XMLPersistenceMetaDataParser.startSystemElement().
> >
> > The processing in this method is dependent on whether the given
> > element is a
> > MetaDataTag or not.  When we process the "entity-listener" element,
> > it's
> > treated like a "normal" element and we fall past the switch
> > statement and
> > eventually call startEntityListener().  This processing all seems
> > to depend
> > on whether the _elems hashmap contains a string entry or a
> > MetatDataTag for
> > a given Element.  What is the significance of being a MetaDataTag
> > or not?
> >
> > In this simple orm.xml, I have noticed that persistence-unit-metadata,
> > persistence-unit-defaults, and entity-listener are not
> > MetaDataTags.  But,
> > entity-listeners and the individual pre-persist, post-persist, etc
> > elements
> > are all MetaDataTags.
> >
> > When one of these pre-* or post-* MetaDataTag elements are
> > processed in the
> > startSystemElement() method, we fall into the default leg of the
> > switch
> > statement and produce the TRACE message outlined above.
> >
> > Any pointers would be appreciated.  Thanks!
> >
> > Kevin
>
>

Re: Processing "system level" entity listeners

Posted by Marc Prud'hommeaux <mp...@apache.org>.
Kevin-

The draft of the JPA spec said that "pre-persist" was only supported  
beneath the "entity-listeners" (note plural) element, rather than  
"entity-listener". This appears to have been corrected in the final  
version of the spec, but it looks like we never updated that part of  
the code (and the CTS doesn't test for it). This is indeed a bug.

As for how the parser works, I'm afraid I don't know all that much  
about it (aside from sharing your observation that it is complex).  
Hopefully, though, my comment above will make the problem make a  
little more sense to you...



On Jan 16, 2007, at 3:20 PM, Kevin Sutter wrote:

> Looking for some assistance (that is, background information) on  
> how the
> orm.xml parsing is supposed to work.  I'm attempting to specify  
> some entity
> listeners in my orm.xml, but I continue to get the following TRACE  
> message:
>
> 322664  my persistence unit  TRACE  [main] openjpa.MetaData -  
> OpenJPA does
> not currently support XML element "pre-persist". Ignoring.
>
> My orm.xml looks like this:
>
> <entity-mappings
>    xmlns="http://java.sun.com/xml/ns/persistence/orm"
>    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm
> http://java.sun.com/xml/ns/persistence/orm_1_0.xsd"
>    version="1.0">
>    <persistence-unit-metadata>
>        <persistence-unit-defaults>
>            <entity-listeners>
>                <entity-listener class="
> com.ibm.ws.persistence.tests.simple.TestEntity">
>                    <pre-persist  method-name="prePersist" />
>                    <post-persist method-name="postPersist" />
>                    <pre-remove   method-name="preRemove" />
>                    <post-remove  method-name="postRemove" />
>                    <pre-update   method-name="preUpdate" />
>                    <post-update  method-name="postUpdate" />
>                    <post-load    method-name="postLoad" />
>                </entity-listener>
>            </entity-listeners>
>        </persistence-unit-defaults>
>    </persistence-unit-metadata>
> </entity-mappings>
>
> I've started to debug this problem, but I have some general  
> questions on how
> the SAX parser is supposed to work.  I see in the
> CFMetaDataParser.startElement() where these "entity-listener"  
> related tags
> are treated as System Elements -- we end up calling
> XMLPersistenceMetaDataParser.startSystemElement().
>
> The processing in this method is dependent on whether the given  
> element is a
> MetaDataTag or not.  When we process the "entity-listener" element,  
> it's
> treated like a "normal" element and we fall past the switch  
> statement and
> eventually call startEntityListener().  This processing all seems  
> to depend
> on whether the _elems hashmap contains a string entry or a  
> MetatDataTag for
> a given Element.  What is the significance of being a MetaDataTag  
> or not?
>
> In this simple orm.xml, I have noticed that persistence-unit-metadata,
> persistence-unit-defaults, and entity-listener are not  
> MetaDataTags.  But,
> entity-listeners and the individual pre-persist, post-persist, etc  
> elements
> are all MetaDataTags.
>
> When one of these pre-* or post-* MetaDataTag elements are  
> processed in the
> startSystemElement() method, we fall into the default leg of the  
> switch
> statement and produce the TRACE message outlined above.
>
> Any pointers would be appreciated.  Thanks!
>
> Kevin