Mailing-List: contact cayenne-user-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: cayenne-user@incubator.apache.org
Received-SPF: neutral (asf.osuosl.org: local policy)
Date: Tue, 29 Aug 2006 19:50:52 -0400
From: =?ISO-8859-1?Q?Jonathan_B=E9lisle?= <jonathan.belisle@rcda.ca>
Subject: Re: DataContext synchronization bug ?
In-reply-to: <44F4B724.6010902@maine.rr.com>
To: cayenne-user@incubator.apache.org
Message-id: <44F4D2DC.80600@rcda.ca>
MIME-version: 1.0
Content-type: text/plain; charset=ISO-8859-1; format=flowed
Content-transfer-encoding: 8BIT
References: <44F20182.2030806@rcda.ca>
 <78B591AA-8116-482C-9BA0-009FE03AADBC@ish.com.au> <44F33AA3.1070402@rcda.ca>
 <6E87D0A6-0F0A-4ACE-B1F8-FC8269849362@ish.com.au> <44F38FF7.9060408@rcda.ca>
 <EA9DA036-70BA-4F77-AF1C-3E426F0E773A@ish.com.au> <44F4A3D1.8080307@rcda.ca>
 <44F4B724.6010902@maine.rr.com>
User-Agent: Thunderbird 1.5.0.5 (Windows/20060719)

I printed the list of updated objects and my object is there with the 
persistance state to MODIFIED.
And I am committing the right dataContext : dataContext2

Event then, committing one or the other data context should write the 
changes to the database.


Bryan Lewis wrote:
> This might not help much, but...  I've been wrestling with a somewhat
> similar issue, and it turned out to be a silly bug of my own.  I wasn't
> committing in the right DataContext.  I'm reminded of that when you say 
> "Still not working" after trying Marcin's suggestion of touching some
> attribute of the localObject.  If it's still not saving after that,
> maybe the object isn't in the DataContext you're committing.  Could you
> print the list of updated objects in the DC just before the commit?  
> Something like this:
>
>         Collection objects = dc.newObjects();
>         objects.addAll(dc.modifiedObjects());
>         objects.addAll(dc.deletedObjects());
>
>         Iterator it = objects.iterator();
>         while (it.hasNext()) {
>             log.debug(it.next());
>         }
>
>
>
>
> Jonathan B�lisle wrote:
>   
>> Hi,
>>
>> Still not working.
>> Is it the normal behavior of localObject() or is it a bug ?
>> It seems to me that there should be a way to copy a modified object to
>> a different dataContext
>> while keeping it's modification info.
>>
>> Maybe I'm not doing it the right way.
>> Maybe localObject() is not the right way.
>>
>> Somebody know the right way ?
>>
>> Jonathan
>>
>>
>> Marcin Skladaniec wrote:
>>     
>>> Hi
>>> I'm not using localObject with prototype at the moment. I had some
>>> problems with it as well.
>>> Please try after doing localObject retouching some attribute, like
>>> dataObjectInContext2.setName(getName()),  commit and see if this will
>>> put to the database only the new name.
>>>
>>> Marcin
>>>
>>> On 29/08/2006, at 10:53 AM, Jonathan B�lisle wrote:
>>>
>>>       
>>>> Hi,
>>>>
>>>> It should work but it does not.
>>>>
>>>> context2.commitChanges() won't send an update statement to the
>>>> database if the object was modified in context1.
>>>>
>>>> I think it's not working because context2 was not notified of the
>>>> changes made to dataObject while it was in context1.
>>>>
>>>> Is it working for you ?
>>>> Try the code from the previous post. You will see that nothing gets
>>>> written to the database on commit.
>>>> If it does well..... there's something wrong somewhere :)
>>>>
>>>> Jonathan
>>>>
>>>>
>>>> Marcin Skladaniec wrote:
>>>>         
>>>>> Hello !
>>>>>
>>>>> I think you have it all right, but just in case:
>>>>> dataObjectInContext2=
>>>>> context2.localObject(dataObjectInContext1.getObjectId(),
>>>>> dataObjectInContext1);
>>>>> dataObjectInContext2.setPersistenceState(dataObjectInContext1.getPersistenceState()
>>>>> ); //In case that the object 1 state is NEW
>>>>> context2.commitChanges();
>>>>> Is it that dead simple or you are doing some more things ?
>>>>> I don't see a reason why it is not working for you.
>>>>> Marcin
>>>>>
>>>>>
>>>>> On 29/08/2006, at 4:49 AM, Jonathan B�lisle wrote:
>>>>>
>>>>>           
>>>>>> Hi Marcin,
>>>>>>
>>>>>> I've already looked at localObject() and it's not good.
>>>>>> Here's why ?
>>>>>>
>>>>>> You have a data object : dataObjectInContext1
>>>>>> You modify a property : dataObjectInContext1.setName("the new name");
>>>>>> You copy it to the second dataContext and modify it's
>>>>>> persistenceState
>>>>>>
>>>>>>    dataObjectInContext2=
>>>>>> context2.localObject(dataObjectInContext1.getObjectId(),
>>>>>> dataObjectInContext1);
>>>>>>   
>>>>>> dataObjectInContext2.setPersistenceState(PersistenceState.MODIFIED);
>>>>>>
>>>>>> Everything is ok till now but here is the problem :
>>>>>>
>>>>>>    dataObjectInContext2.commitChanges();
>>>>>>
>>>>>> Nothing will be written to the database because context2 did not
>>>>>> track changes of dataObjectInContext2.
>>>>>> That's why i'm not using localObject().
>>>>>> Is there a way that dataObjectInContext2 will be committed using
>>>>>> localObject() ?
>>>>>>
>>>>>> I'm using Cayenne 1.2
>>>>>>
>>>>>> Jonathan.
>>>>>>
>>>>>>
>>>>>> Marcin Skladaniec wrote:
>>>>>>             
>>>>>>> Hello Jonathan
>>>>>>>
>>>>>>> Please take a closer look on the localObject() method.
>>>>>>> Straight from javadocs :
>>>>>>> "Returns an object local to this DataContext and matching the
>>>>>>> ObjectId. If prototype is not null, local object is refreshed
>>>>>>> with the prototype values.
>>>>>>>
>>>>>>> In case you pass a non-null second parameter, you are responsible
>>>>>>> for setting correct persistence state of the returned local
>>>>>>> object, as generally there is no way for Cayenne to determine the
>>>>>>> resulting local object state."
>>>>>>>
>>>>>>> If you have still problems please mention what version of cayenne
>>>>>>> are you using.
>>>>>>>
>>>>>>> Marcin
>>>>>>> -------------------------->
>>>>>>> ish
>>>>>>> http://www.ish.com.au
>>>>>>> Level 1, 30 Wilson Street Newtown 2042 Australia
>>>>>>> phone +61 2 9550 5001   fax +61 2 9550 4001
>>>>>>>
>>>>>>>
>>>>>>> On 28/08/2006, at 6:33 AM, Jonathan B�lisle wrote:
>>>>>>>
>>>>>>>               
>>>>>>>> Hi, maybe someone can help me here.
>>>>>>>>
>>>>>>>> I'm trying to copy a dataObject to another dataContext while
>>>>>>>> keeping
>>>>>>>> it's modified state so that it will be correctly committed to
>>>>>>>> the db by the second dataContext.
>>>>>>>>
>>>>>>>> Let say we have an entity with an attribute Name and a
>>>>>>>> relationship Category.
>>>>>>>> The object 1000001 exist in the db and has a Name and a Category
>>>>>>>>
>>>>>>>> //Create the dataContext
>>>>>>>> DataContext dc1= DataContext.createDataContext();
>>>>>>>> DataContext dc2= DataContext.createDataContext();
>>>>>>>>
>>>>>>>> //Get object from db. Modify the name.
>>>>>>>> Animal from= (Animal) DataObjectUtils.objectForPK(dc1, new
>>>>>>>> ObjectId("Animal", "animalId", 1000001));
>>>>>>>> from.setName("XXX" + new SecureRandom().nextInt());
>>>>>>>>
>>>>>>>> //Get local object to dc2
>>>>>>>> //I cannot use dc2.localObject(from.getObjectId(), from);
>>>>>>>> //because the dc2 won't see the modification made in dc1.
>>>>>>>> Animal to= (Animal) dc2.localObject(from.getObjectId(), null);
>>>>>>>> dc2.getObjectStore().resolveHollow(to);
>>>>>>>>
>>>>>>>> //Copy the attributes from object1 to object2      String attName;
>>>>>>>> ObjAttribute objAttribute;
>>>>>>>> ObjEntity objEntity=
>>>>>>>> from.getObjectContext().getEntityResolver().lookupObjEntity(to);
>>>>>>>> Iterator attributes = objEntity.getAttributes().iterator();
>>>>>>>> while (attributes.hasNext()) {
>>>>>>>>    objAttribute = (ObjAttribute) attributes.next();
>>>>>>>>    attName= objAttribute.getName();
>>>>>>>>
>>>>>>>>    to.writeProperty(attName, from.readPropertyDirectly(attName));
>>>>>>>> }
>>>>>>>>       dc2.commitChanges();
>>>>>>>>
>>>>>>>> System.out.println(from);
>>>>>>>> System.out.println(to);
>>>>>>>>
>>>>>>>> Everything is committed correctly to the db but the object from
>>>>>>>> has now a Category = null
>>>>>>>>
>>>>>>>> The problem is after the dc2.commitChanges() and
>>>>>>>> it comes from
>>>>>>>> org.objectstyle.cayenne.event.EventManager.DispatchThread.run()
>>>>>>>> witch is firing an event to set the relationship Category to null.
>>>>>>>> I don't know why it is doing that.
>>>>>>>> I am doing something wrong ? Is it a bug in cayenne ?
>>>>>>>> And i need context synchronization so turning it off is not an
>>>>>>>> option.
>>>>>>>>
>>>>>>>> I really need help on this one, can someone help me ?
>>>>>>>>
>>>>>>>> Jonathan
>>>>>>>>                 
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>               
>>>>> -------------------------->
>>>>> ish
>>>>> http://www.ish.com.au
>>>>> Level 1, 30 Wilson Street Newtown 2042 Australia
>>>>> phone +61 2 9550 5001   fax +61 2 9550 4001
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>           
>>> -------------------------->
>>> ish
>>> http://www.ish.com.au
>>> Level 1, 30 Wilson Street Newtown 2042 Australia
>>> phone +61 2 9550 5001   fax +61 2 9550 4001
>>>
>>>
>>>
>>>
>>>
>>>       
>
>
>
>
>
>