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Posted to user@cayenne.apache.org by Simran Narula <sn...@avoka.com> on 2012/03/28 06:58:31 UTC
Track Column level changes in Cayenne
Hi,
I need to log each action taken on my portal UI for e.g.
Price changed for product x
Assume all the information is contained within one table i.e.both price & the product information.
When the portal is loaded with product information, user can change the price of the product.
I want to check if the price has changed or not and for that I am using a pre-update call back in Cayenne entity to check these changes, I want to check if the price x is changed to Y and push another history record in the Database. So far I have tried cache strategies - NO_CACHE and other workarounds but no success yet.
surely I can achieve this by other hacky means, but do not want to. My question is... is there any way to track column level changes in Cayenne ?
Thanks.
Simran
RE: Track Column level changes in Cayenne
Posted by Simran Narula <sn...@avoka.com>.
Don't worry about this !
The culprit was incorrect configuration in db
-----Original Message-----
From: Simran Narula [mailto:snarula@avoka.com]
Sent: Tuesday, 10 April 2012 1:55 PM
To: user@cayenne.apache.org
Subject: RE: Track Column level changes in Cayenne
Hi Guys,
Looks like need a little more help on below,
I am getting
The INSERT statement conflicted with the FOREIGN KEY constraint "X_Constraint". The conflict occurred in database "MyDatabase", table "dbo.X", column 'X_oid'.
As raised earlier, I want to track column level changes on a particular entity, and for that Andrus advised me to get a parallel context and retrieve same object from the database and do the comparison Between the entity (that might have changed values) and fresh object that I have retrieved from the database using the parallel ObjectContext.
What I am doing is below,
On the save click on a page, I am saving the entity X like this:
myEntityService.save(X)
// where save() just checks if it's a new object and registers it, otherwise just commits the changes using commitChanges();
Then, I have preUpdate() callback on X Entity Class, like this:
onPreUpdate() {
if (hasPropertyValueChanged(properyNameConstant))
{
ObjectContext context = DataContext.getThreadObjectContext();
Log l = (Log)context.newObject(Log.class);
// populate log instance with whatever details
addToLog(l);
}
}
Where addToLog()... is simply addToManyTarget("Log", obj, true);
... and finally, I have the hasPropertyValueChanged is something like this...
hasPropertyValueChanged(String properyName) {
ObjectContext parallelContext = DataContext.createDataContext(false);
ObjEntity objEntity = parallelContext.getEntityResolver().lookupObjEntity(entityClass);
String pkName = CayenneUtils.getPkName(entityClass);
ObjectId objectId = new ObjectId(objEntity.getName(), pkName, pkId);
ObjectIdQuery objectIdQuery = new ObjectIdQuery(objectId, false, ObjectIdQuery.CACHE_REFRESH);
MyBaseEntity persistedObject = (MyBaseEntity) DataObjectUtils.objectForQuery(parallelContext, objectIdQuery);
// Compare the value in the current entity object (where we suspect the value to might have changed of a particular column) and the persisted object that we just obtained
// if the value has been changed then return true... allowing the new Log to be created...
}
Once this is executed.. I get a
The INSERT statement conflicted with the FOREIGN KEY constraint "X_Constraint". The conflict occurred in database "MyDatabase", table "dbo.X", column 'X_oid'.
Which eventually causes the
CommitException...
Why am I getting this... ? I know its complaining about foreign key constraint, on my X table which is represented by X entity in the code examples above, the Log table has a foreign key reference to X_oid in X Table
[Click] [error] handleException: org.apache.cayenne.CayenneRuntimeException: [v.3.0.2 Jun 11 2011 09:52:20] Commit Exception
at org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:1149)
at org.apache.cayenne.access.DataContext.commitChanges(DataContext.java:1060)
at XXX.CayenneService.commitChanges(CayenneService.java:X)
at XXX.EntityService.save(EntityService.java:X)
at XXX.onSaveClick(MyPage.java:X)
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:585)
at org.apache.click.util.ClickUtils.invokeListener(ClickUtils.java:1949)
at org.apache.click.util.ActionListenerAdaptor.onAction(ActionListenerAdaptor.java:59)
at org.apache.click.ActionEventDispatcher.fireActionEvent(ActionEventDispatcher.java:248)
at org.apache.click.ActionEventDispatcher.fireActionEvents(ActionEventDispatcher.java:193)
at org.apache.click.ActionEventDispatcher$EventHolder.fireActionEvents(ActionEventDispatcher.java:430)
at org.apache.click.ActionEventDispatcher.fireActionEvents(ActionEventDispatcher.java:226)
at org.apache.click.ActionEventDispatcher.fireActionEvents(ActionEventDispatcher.java:212)
at org.apache.click.ClickServlet.performOnProcess(ClickServlet.java:666)
at org.apache.click.ClickServlet.processPage(ClickServlet.java:562)
at org.apache.click.ClickServlet.handleRequest(ClickServlet.java:379)
at org.apache.click.ClickServlet.doPost(ClickServlet.java:294)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at xxx
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at xxx
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
<...irrelevant lines truncated>
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at xxx
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:595)
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The INSERT statement conflicted with the FOREIGN KEY constraint "X_Contraint". The conflict occurred in database "MyDatabase", table "dbo.X", column 'X_oid'.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(Unknown Source)
at com.microsoft.sqlserver.jdbc.IOBuffer.processPackets(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.sendExecute(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.doExecuteUpdate(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeUpdate(Unknown Source)
at org.apache.cayenne.access.jdbc.BatchAction.runAsIndividualQueries(BatchAction.java:221)
at org.apache.cayenne.access.jdbc.BatchAction.performAction(BatchAction.java:91)
at org.apache.cayenne.dba.sqlserver.SQLServerBatchAction.performAction(SQLServerBatchAction.java:59)
at org.apache.cayenne.access.DataNodeQueryAction.runQuery(DataNodeQueryAction.java:87)
at org.apache.cayenne.access.DataNode.performQueries(DataNode.java:269)
at org.apache.cayenne.access.DataDomainFlushAction.runQueries(DataDomainFlushAction.java:226)
at org.apache.cayenne.access.DataDomainFlushAction.flush(DataDomainFlushAction.java:144)
at org.apache.cayenne.access.DataDomain.onSyncFlush(DataDomain.java:824)
at org.apache.cayenne.access.DataDomain$2.transform(DataDomain.java:791)
at org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:850)
at org.apache.cayenne.access.DataDomain.onSync(DataDomain.java:788)
at org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:1121)
... 65 more
-----Original Message-----
From: Simran Narula
Sent: Thursday, 5 April 2012 1:54 PM
To: 'user@cayenne.apache.org'
Subject: RE: Track Column level changes in Cayenne
Hey Andrus,
Thanks for your reply that day.
Just wanted to let you know this Worked !!
Thanks heaps for help !
-----Original Message-----
From: Andrus Adamchik [mailto:andrus@objectstyle.org]
Sent: Wednesday, 28 March 2012 6:50 PM
To: user@cayenne.apache.org
Subject: Re: Track Column level changes in Cayenne
(reposting from stackoverflow answer)
There are a few ways to approach this. Here is the one that IMO is the most transparent. The trick is to use a different ObjectContext from the one committing changes. Then you will get a separate copy of the object that will contain currently saved value:
// 'this' refers to the DataObject being committed (assuming things happen in its callback)
ObjectContext parallelContext = ... // create a new context here like you normally would
// 3.1 API; 3.0.x has a similar method with a slightly different sig
MyClass clone = parallelContext.localObject(this);
// if you are ok with cached old value, ignore the 'invalidateObjects' call.
// If not, uncomment it to ensure the object gets refetched.
// Also 3.1 API. Should be easy to adjust for 3.0
// parallelContext.invalidateObjects(clone);
Object oldValue = clone.getXyz();
Andrus
On Mar 28, 2012, at 7:58 AM, Simran Narula wrote:
> Hi,
>
> I need to log each action taken on my portal UI for e.g.
>
> Price changed for product x
>
> Assume all the information is contained within one table i.e.both price & the product information.
>
> When the portal is loaded with product information, user can change the price of the product.
>
> I want to check if the price has changed or not and for that I am using a pre-update call back in Cayenne entity to check these changes, I want to check if the price x is changed to Y and push another history record in the Database. So far I have tried cache strategies - NO_CACHE and other workarounds but no success yet.
>
> surely I can achieve this by other hacky means, but do not want to. My question is... is there any way to track column level changes in Cayenne ?
>
> Thanks.
> Simran
>
>
RE: Track Column level changes in Cayenne
Posted by Simran Narula <sn...@avoka.com>.
Hi Guys,
Looks like need a little more help on below,
I am getting
The INSERT statement conflicted with the FOREIGN KEY constraint "X_Constraint". The conflict occurred in database "MyDatabase", table "dbo.X", column 'X_oid'.
As raised earlier, I want to track column level changes on a particular entity, and for that Andrus advised me to get a parallel context and retrieve same object from the database and do the comparison
Between the entity (that might have changed values) and fresh object that I have retrieved from the database using the parallel ObjectContext.
What I am doing is below,
On the save click on a page, I am saving the entity X like this:
myEntityService.save(X)
// where save() just checks if it's a new object and registers it, otherwise just commits the changes using commitChanges();
Then, I have preUpdate() callback on X Entity Class, like this:
onPreUpdate() {
if (hasPropertyValueChanged(properyNameConstant))
{
ObjectContext context = DataContext.getThreadObjectContext();
Log l = (Log)context.newObject(Log.class);
// populate log instance with whatever details
addToLog(l);
}
}
Where addToLog()... is simply addToManyTarget("Log", obj, true);
... and finally, I have the hasPropertyValueChanged is something like this...
hasPropertyValueChanged(String properyName) {
ObjectContext parallelContext = DataContext.createDataContext(false);
ObjEntity objEntity = parallelContext.getEntityResolver().lookupObjEntity(entityClass);
String pkName = CayenneUtils.getPkName(entityClass);
ObjectId objectId = new ObjectId(objEntity.getName(), pkName, pkId);
ObjectIdQuery objectIdQuery = new ObjectIdQuery(objectId, false, ObjectIdQuery.CACHE_REFRESH);
MyBaseEntity persistedObject = (MyBaseEntity) DataObjectUtils.objectForQuery(parallelContext, objectIdQuery);
// Compare the value in the current entity object (where we suspect the value to might have changed of a particular column) and the persisted object that we just obtained
// if the value has been changed then return true... allowing the new Log to be created...
}
Once this is executed.. I get a
The INSERT statement conflicted with the FOREIGN KEY constraint "X_Constraint". The conflict occurred in database "MyDatabase", table "dbo.X", column 'X_oid'.
Which eventually causes the
CommitException...
Why am I getting this... ? I know its complaining about foreign key constraint, on my X table which is represented by X entity in the code examples above, the Log table has a foreign key reference to X_oid in X Table
[Click] [error] handleException: org.apache.cayenne.CayenneRuntimeException: [v.3.0.2 Jun 11 2011 09:52:20] Commit Exception
at org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:1149)
at org.apache.cayenne.access.DataContext.commitChanges(DataContext.java:1060)
at XXX.CayenneService.commitChanges(CayenneService.java:X)
at XXX.EntityService.save(EntityService.java:X)
at XXX.onSaveClick(MyPage.java:X)
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:585)
at org.apache.click.util.ClickUtils.invokeListener(ClickUtils.java:1949)
at org.apache.click.util.ActionListenerAdaptor.onAction(ActionListenerAdaptor.java:59)
at org.apache.click.ActionEventDispatcher.fireActionEvent(ActionEventDispatcher.java:248)
at org.apache.click.ActionEventDispatcher.fireActionEvents(ActionEventDispatcher.java:193)
at org.apache.click.ActionEventDispatcher$EventHolder.fireActionEvents(ActionEventDispatcher.java:430)
at org.apache.click.ActionEventDispatcher.fireActionEvents(ActionEventDispatcher.java:226)
at org.apache.click.ActionEventDispatcher.fireActionEvents(ActionEventDispatcher.java:212)
at org.apache.click.ClickServlet.performOnProcess(ClickServlet.java:666)
at org.apache.click.ClickServlet.processPage(ClickServlet.java:562)
at org.apache.click.ClickServlet.handleRequest(ClickServlet.java:379)
at org.apache.click.ClickServlet.doPost(ClickServlet.java:294)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at xxx
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at xxx
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
<...irrelevant lines truncated>
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at xxx
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:595)
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The INSERT statement conflicted with the FOREIGN KEY constraint "X_Contraint". The conflict occurred in database "MyDatabase", table "dbo.X", column 'X_oid'.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(Unknown Source)
at com.microsoft.sqlserver.jdbc.IOBuffer.processPackets(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.sendExecute(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.doExecuteUpdate(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeUpdate(Unknown Source)
at org.apache.cayenne.access.jdbc.BatchAction.runAsIndividualQueries(BatchAction.java:221)
at org.apache.cayenne.access.jdbc.BatchAction.performAction(BatchAction.java:91)
at org.apache.cayenne.dba.sqlserver.SQLServerBatchAction.performAction(SQLServerBatchAction.java:59)
at org.apache.cayenne.access.DataNodeQueryAction.runQuery(DataNodeQueryAction.java:87)
at org.apache.cayenne.access.DataNode.performQueries(DataNode.java:269)
at org.apache.cayenne.access.DataDomainFlushAction.runQueries(DataDomainFlushAction.java:226)
at org.apache.cayenne.access.DataDomainFlushAction.flush(DataDomainFlushAction.java:144)
at org.apache.cayenne.access.DataDomain.onSyncFlush(DataDomain.java:824)
at org.apache.cayenne.access.DataDomain$2.transform(DataDomain.java:791)
at org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:850)
at org.apache.cayenne.access.DataDomain.onSync(DataDomain.java:788)
at org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:1121)
... 65 more
-----Original Message-----
From: Simran Narula
Sent: Thursday, 5 April 2012 1:54 PM
To: 'user@cayenne.apache.org'
Subject: RE: Track Column level changes in Cayenne
Hey Andrus,
Thanks for your reply that day.
Just wanted to let you know this Worked !!
Thanks heaps for help !
-----Original Message-----
From: Andrus Adamchik [mailto:andrus@objectstyle.org]
Sent: Wednesday, 28 March 2012 6:50 PM
To: user@cayenne.apache.org
Subject: Re: Track Column level changes in Cayenne
(reposting from stackoverflow answer)
There are a few ways to approach this. Here is the one that IMO is the most transparent. The trick is to use a different ObjectContext from the one committing changes. Then you will get a separate copy of the object that will contain currently saved value:
// 'this' refers to the DataObject being committed (assuming things happen in its callback)
ObjectContext parallelContext = ... // create a new context here like you normally would
// 3.1 API; 3.0.x has a similar method with a slightly different sig
MyClass clone = parallelContext.localObject(this);
// if you are ok with cached old value, ignore the 'invalidateObjects' call.
// If not, uncomment it to ensure the object gets refetched.
// Also 3.1 API. Should be easy to adjust for 3.0
// parallelContext.invalidateObjects(clone);
Object oldValue = clone.getXyz();
Andrus
On Mar 28, 2012, at 7:58 AM, Simran Narula wrote:
> Hi,
>
> I need to log each action taken on my portal UI for e.g.
>
> Price changed for product x
>
> Assume all the information is contained within one table i.e.both price & the product information.
>
> When the portal is loaded with product information, user can change the price of the product.
>
> I want to check if the price has changed or not and for that I am using a pre-update call back in Cayenne entity to check these changes, I want to check if the price x is changed to Y and push another history record in the Database. So far I have tried cache strategies - NO_CACHE and other workarounds but no success yet.
>
> surely I can achieve this by other hacky means, but do not want to. My question is... is there any way to track column level changes in Cayenne ?
>
> Thanks.
> Simran
>
>
RE: Track Column level changes in Cayenne
Posted by Simran Narula <sn...@avoka.com>.
By the way, Cayenne should allow checking if a particular value has been changed, may be in the future releases
-----Original Message-----
From: Simran Narula [mailto:snarula@avoka.com]
Sent: Thursday, 5 April 2012 1:54 PM
To: user@cayenne.apache.org
Subject: RE: Track Column level changes in Cayenne
Hey Andrus,
Thanks for your reply that day.
Just wanted to let you know this Worked !!
Thanks heaps for help !
-----Original Message-----
From: Andrus Adamchik [mailto:andrus@objectstyle.org]
Sent: Wednesday, 28 March 2012 6:50 PM
To: user@cayenne.apache.org
Subject: Re: Track Column level changes in Cayenne
(reposting from stackoverflow answer)
There are a few ways to approach this. Here is the one that IMO is the most transparent. The trick is to use a different ObjectContext from the one committing changes. Then you will get a separate copy of the object that will contain currently saved value:
// 'this' refers to the DataObject being committed (assuming things happen in its callback)
ObjectContext parallelContext = ... // create a new context here like you normally would
// 3.1 API; 3.0.x has a similar method with a slightly different sig
MyClass clone = parallelContext.localObject(this);
// if you are ok with cached old value, ignore the 'invalidateObjects' call.
// If not, uncomment it to ensure the object gets refetched.
// Also 3.1 API. Should be easy to adjust for 3.0
// parallelContext.invalidateObjects(clone);
Object oldValue = clone.getXyz();
Andrus
On Mar 28, 2012, at 7:58 AM, Simran Narula wrote:
> Hi,
>
> I need to log each action taken on my portal UI for e.g.
>
> Price changed for product x
>
> Assume all the information is contained within one table i.e.both price & the product information.
>
> When the portal is loaded with product information, user can change the price of the product.
>
> I want to check if the price has changed or not and for that I am using a pre-update call back in Cayenne entity to check these changes, I want to check if the price x is changed to Y and push another history record in the Database. So far I have tried cache strategies - NO_CACHE and other workarounds but no success yet.
>
> surely I can achieve this by other hacky means, but do not want to. My question is... is there any way to track column level changes in Cayenne ?
>
> Thanks.
> Simran
>
>
RE: Track Column level changes in Cayenne
Posted by Simran Narula <sn...@avoka.com>.
Hey Andrus,
Thanks for your reply that day.
Just wanted to let you know this Worked !!
Thanks heaps for help !
-----Original Message-----
From: Andrus Adamchik [mailto:andrus@objectstyle.org]
Sent: Wednesday, 28 March 2012 6:50 PM
To: user@cayenne.apache.org
Subject: Re: Track Column level changes in Cayenne
(reposting from stackoverflow answer)
There are a few ways to approach this. Here is the one that IMO is the most transparent. The trick is to use a different ObjectContext from the one committing changes. Then you will get a separate copy of the object that will contain currently saved value:
// 'this' refers to the DataObject being committed (assuming things happen in its callback)
ObjectContext parallelContext = ... // create a new context here like you normally would
// 3.1 API; 3.0.x has a similar method with a slightly different sig
MyClass clone = parallelContext.localObject(this);
// if you are ok with cached old value, ignore the 'invalidateObjects' call.
// If not, uncomment it to ensure the object gets refetched.
// Also 3.1 API. Should be easy to adjust for 3.0
// parallelContext.invalidateObjects(clone);
Object oldValue = clone.getXyz();
Andrus
On Mar 28, 2012, at 7:58 AM, Simran Narula wrote:
> Hi,
>
> I need to log each action taken on my portal UI for e.g.
>
> Price changed for product x
>
> Assume all the information is contained within one table i.e.both price & the product information.
>
> When the portal is loaded with product information, user can change the price of the product.
>
> I want to check if the price has changed or not and for that I am using a pre-update call back in Cayenne entity to check these changes, I want to check if the price x is changed to Y and push another history record in the Database. So far I have tried cache strategies - NO_CACHE and other workarounds but no success yet.
>
> surely I can achieve this by other hacky means, but do not want to. My question is... is there any way to track column level changes in Cayenne ?
>
> Thanks.
> Simran
>
>
Re: Track Column level changes in Cayenne
Posted by Andrus Adamchik <an...@objectstyle.org>.
(reposting from stackoverflow answer)
There are a few ways to approach this. Here is the one that IMO is the most transparent. The trick is to use a different ObjectContext from the one committing changes. Then you will get a separate copy of the object that will contain currently saved value:
// 'this' refers to the DataObject being committed (assuming things happen in its callback)
ObjectContext parallelContext = ... // create a new context here like you normally would
// 3.1 API; 3.0.x has a similar method with a slightly different sig
MyClass clone = parallelContext.localObject(this);
// if you are ok with cached old value, ignore the 'invalidateObjects' call.
// If not, uncomment it to ensure the object gets refetched.
// Also 3.1 API. Should be easy to adjust for 3.0
// parallelContext.invalidateObjects(clone);
Object oldValue = clone.getXyz();
Andrus
On Mar 28, 2012, at 7:58 AM, Simran Narula wrote:
> Hi,
>
> I need to log each action taken on my portal UI for e.g.
>
> Price changed for product x
>
> Assume all the information is contained within one table i.e.both price & the product information.
>
> When the portal is loaded with product information, user can change the price of the product.
>
> I want to check if the price has changed or not and for that I am using a pre-update call back in Cayenne entity to check these changes, I want to check if the price x is changed to Y and push another history record in the Database. So far I have tried cache strategies - NO_CACHE and other workarounds but no success yet.
>
> surely I can achieve this by other hacky means, but do not want to. My question is... is there any way to track column level changes in Cayenne ?
>
> Thanks.
> Simran
>
>