Mailing-List: contact commons-dev-help@jakarta.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Jakarta Commons Developers List" <commons-dev@jakarta.apache.org>
Date: Tue, 1 Jul 2003 22:01:23 +0100
Subject: Re: [Betwixt] Derived Class support
Content-Type: text/plain; charset=US-ASCII; format=flowed
Mime-Version: 1.0 (Apple Message framework v482)
From: robert burrell donkin <robertburrelldonkin@blueyonder.co.uk>
To: "Jakarta Commons Developers List" <commons-dev@jakarta.apache.org>
Content-Transfer-Encoding: 7bit
In-Reply-To: <000001c33cc6$a2974680$1ad9c150@RossMason>
Message-Id: <2C1F53FF-AC07-11D7-9785-003065DC754C@blueyonder.co.uk>

hi ross

thanks for the patch. i've taken a quick look at it and it seems fine. 
i'll go through it in detail a little later. (i've got a multiple versions 
checked out at the moment with various patches and enhancements applied so 
it's a little difficult for me just now.)

please you could (in future) post your diffs in -u format (see 
http://jakarta.apache.org/commons/patches.html).

- robert

On Friday, June 27, 2003, at 05:10 PM, Ross Mason wrote:

> Hi Robert,
>
> Sorry for the delay, but things have been very hectic.
>
> I've attached the source code and a CVS diff of the changes I've made for
> the derived bean support.
>
> I'm going away for a few months next week so if you need anything else
> please let me know asap.
>
> There is a minor bug with this patch that occasionally throws an
> IllegalArgumentException when trying to set attributes on a bean.  Even
> though we get this exception the bean's attributes do get set. I think is
> caused when new rules are registered for a derived bean and the digester
> becomes briefly out of sync until the top object is popped and a new 
> derived
> object is created and put on the stack. I have not had time to look into
> this, and as it doesn't cause any problems we have ignored it in our 
> project
> for the time being. I've enclosed a trace for you.
>
> Ross
>
> WARN [main] (MethodUpdater.java:156) - Cannot evaluate method: setName on
> bean: com.estafet.smse.persistence.Occupation@1ee2c2c of type:
> com.estafet.smse.persistence.Occupation with value: Nurse of type:
> java.lang.String
>  INFO [main] (MethodUpdater.java:197) - Caught exception:
> java.lang.IllegalArgumentException: object is not an instance of declaring
> class
> java.lang.IllegalArgumentException: object is not an instance of declaring
> class
> 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> 	at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
> 39
> )
> 	at
> sun.reflect.DelegatingMethodAccessorImpl.invoke
> (DelegatingMethodAccessorImpl
> .java:25)
> 	at java.lang.reflect.Method.invoke(Method.java:324)
> 	at
> org.apache.commons.betwixt.expression.MethodUpdater.update(MethodUpdater.
> jav
> a:152)
> 	at
> org.apache.commons.betwixt.io.BeanRuleSet$ReadContext$PrimitiveRule.body(
> Bea
> nRuleSet.java:576)
> 	at
> org.apache.commons.digester.Digester.endElement(Digester.java:800)
> 	at
> org.apache.xerces.parsers.AbstractSAXParser.endElement(AbstractSAXParser.
> jav
> a:579)
> 	at
> org.apache.xerces.impl.XMLNamespaceBinder.endElement(XMLNamespaceBinder.java
> :646)
> 	at
> org.apache.xerces.impl.dtd.XMLDTDValidator.handleEndElement
> (XMLDTDValidator.
> java:1972)
> 	at
> org.apache.xerces.impl.dtd.XMLDTDValidator.endElement(XMLDTDValidator.java:
> 8
> 78)
> 	at
> org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.handleEndElement
> (XMLDo
> cumentFragmentScannerImpl.java:1144)
> 	at
> org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanEndElement
> (XMLDocu
> mentFragmentScannerImpl.java:987)
> 	at
> org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatc
> her.dispatch(XMLDocumentFragmentScannerImpl.java:1445)
> 	at
> org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument
> (XMLDocume
> ntFragmentScannerImpl.java:333)
> 	at
> org.apache.xerces.parsers.DTDConfiguration.parse(DTDConfiguration.java:524)
> 	at
> org.apache.xerces.parsers.DTDConfiguration.parse(DTDConfiguration.java:580)
> 	at org.apache.xerces.parsers.XMLParser.parse(XMLParser.java:152)
> 	at
> org.apache.xerces.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:
> 116
> 9)
> 	at org.apache.commons.digester.Digester.parse(Digester.java:1322)
> 	at
> com.estafet.smse.message.JournalMessage.create(JournalMessage.java:92)
> 	at
> com.estafet.smse.message.JournalMessage.<init>(JournalMessage.java:46)
> 	at
> com.estafet.smse.test.message.MessagesTest.testJournalMessage
> (MessagesTest.j
> ava:210)
> 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> 	at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:
> 39
> )
> 	at
> sun.reflect.DelegatingMethodAccessorImpl.invoke
> (DelegatingMethodAccessorImpl
> .java:25)
> 	at java.lang.reflect.Method.invoke(Method.java:324)
> 	at junit.framework.TestCase.runTest(TestCase.java:166)
> 	at junit.framework.TestCase.runBare(TestCase.java:140)
> 	at junit.framework.TestResult$1.protect(TestResult.java:106)
> 	at junit.framework.TestResult.runProtected(TestResult.java:124)
> 	at junit.framework.TestResult.run(TestResult.java:109)
> 	at junit.framework.TestCase.run(TestCase.java:131)
> 	at junit.framework.TestSuite.runTest(TestSuite.java:173)
> 	at junit.framework.TestSuite.run(TestSuite.java:168)
> 	at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests
> (RemoteTestRu
> nner.java:392)
> 	at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run
> (RemoteTestRunner.
> java:276)
> 	at
> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main
> (RemoteTestRunner
> .java:167)
>
> -----Original Message-----
> From: robert burrell donkin [mailto:robertburrelldonkin@blueyonder.co.uk]
> Sent: 09 May 2003 16:05
> To: Jakarta Commons Developers List
> Subject: Re: [Betwixt] Derived Class support
>
> hi ross
>
> that all sounds great!
>
> the best way is to do a cvs diff -u against CVS HEAD and either post it to
> the list or add it to bugzilla.
>
> - robert
>
> On Friday, May 2, 2003, at 03:26 PM, Ross Mason wrote:
>
>> Hi James/ Robert,
>>
>>
>>
>> Just to give you an update.  I've got betwixt working with most of the
>> functionality needed for Derived class support -
>>
>>
>>
>> -          Population of derived class attributes from the BeanReader now
>> works.
>>
>> -          It also supports population of beans with common attributes. 
>> i.
>> e.
>> 'Person' has an attribute 'name' only, 'Consultant' and 'Hitman' extend
>> Person.  They both have a attributes hourlyRate, but the attribute is not
>> derived.  I needed this scenario supported in my code.    Currently, only
>> primitive common attribute types are supported.
>>
>> -          To demonstrate this I've written a new test case in the 
>> derived
>> package.  This tests all the old and new functionality and also tests
>> round-tripping.
>>
>> -          I haven't had time to write support in the .betwixt files to
>> specify whether the className attribute should be written for a bean or
>> made
>> the attribute name 'className' configurable (as James suggested) . I've
>> been
>> testing the code with a derived XMLIntrospector that checks to see if the
>> bean being introspected is of a certain base-class type and includes a
>> className attribute descriptor. Maybe we should let users register 
>> derived
>> classes with the XMLIntrospector and determine whether the attribute
>> should
>> be written automatically?
>>
>> -          I've been running my project with this code for the past week
>> without any problems and all the existing test-cases work.
>>
>>
>>
>> The code I've written does the job but there may be better ways of doing
>> it
>> (especially the support for common attributes).   Betwixt as it stands is
>> pretty hard to extend and it's apparent that certain areas need
>> re-factoring/ re-architecting.  I would be keen to get involved with 
>> this,
>> but I'm pretty busy with other stuff for the next 6 weeks.
>>
>>
>>
>> Anyway, what now? How do you want me to get the code to you so you can
>> check
>> it over?
>>
>>
>>
>>
>>
>> Ross
>>
>> -------------------------------------------
>>
>> Mobile: +44 (0) 7745 944 082
>>
>> Work:  +44 (0) 20 7503 4811
>>
>> Fax:      +44 (0) 20 7503 4811
>>
>>
>>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>
>   ---------------------------------------------------------------------
> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: commons-dev-help@jakarta.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: commons-dev-help@jakarta.apache.org