[jira] Commented: (CAY-436) In modeler, change default object relationship delete rule

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    [ https://issues.apache.org/cayenne/browse/CAY-436?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12986#action_12986 ]

Kevin Menard commented on CAY-436:
----------------------------------

All in all, this looks pretty good.  A couple questions:

1) In DbLoaderHelper, is there any reason that you need to explicitly update the ObjEntity?  Or rather, is there a reason that your observer pattern fails to work here?

2) Is there a reason that the observer pattern fails in ObjRelationshipInfoModel#savePath?

I may be looking at the code wrong, but it strikes me that the EntityMergeListener or something similar could be used in such a way that you don't actually have to hook in explicit updates in so many places.

> In modeler, change default object relationship delete rule
> ----------------------------------------------------------
>
>                 Key: CAY-436
>                 URL: https://issues.apache.org/cayenne/browse/CAY-436
>             Project: Cayenne
>          Issue Type: Improvement
>          Components: Cayenne Core Library, CayenneModeler GUI
>         Environment: winxp, M7
>            Reporter: weidox
>            Assignee: Kevin Menard
>             Fix For: UNDEFINED FUTURE
>
>         Attachments: patch-CAY-436.txt
>
>
> Should be good to change default delete rules for object relationships, one to many - cascade, and vice versa - to nullify. I think it's the rules used mostly for these relationships.
> And the best thing would be to have configurable options for these, but that's more complex.

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[Andrey Razumovsky]

The first and obvious reason was to use 'common' callbacks - like
EntityListener and DataMapListener. But that would really make life harder
because I need not change the rule every time. For instance, I probably
don't wan't to mess with it when I will code copy-paste. Finally, as long as
I remember, 'add' events are not fired sometimes (for instance, when
syncronizing Db and Obj entities.
Other rule for me was not to break into main core. Def rules are likely
modeler's property and jdk-1.5-unpublished need not know about them. So I
ended in manually checking all the places where a new relationship is
created.
To answer directly to your question, now I see that EntityMergeListener can
work in DbLoader if we add the same API to work with EntityMergeListeners
and then pass them to EntityMergeSupport. Still, there's DbLoaderHelper. I
need to save entities to an array first because it comes to the helper
without any relationships yet synchronized.

2008/6/30, Kevin Menard (JIRA) <dev@...>:

>
>
>     [
> https://issues.apache.org/cayenne/browse/CAY-436?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12986#action_12986]
>
> Kevin Menard commented on CAY-436:
> ----------------------------------
>
> All in all, this looks pretty good.  A couple questions:
>
> 1) In DbLoaderHelper, is there any reason that you need to explicitly
> update the ObjEntity?  Or rather, is there a reason that your observer
> pattern fails to work here?
>
> 2) Is there a reason that the observer pattern fails in
> ObjRelationshipInfoModel#savePath?
>
> I may be looking at the code wrong, but it strikes me that the
> EntityMergeListener or something similar could be used in such a way that
> you don't actually have to hook in explicit updates in so many places.
>
> > In modeler, change default object relationship delete rule
> > ----------------------------------------------------------
> >
> >                 Key: CAY-436
> >                 URL: https://issues.apache.org/cayenne/browse/CAY-436
> >             Project: Cayenne
> >          Issue Type: Improvement
> >          Components: Cayenne Core Library, CayenneModeler GUI
> >         Environment: winxp, M7
> >            Reporter: weidox
> >            Assignee: Kevin Menard
> >             Fix For: UNDEFINED FUTURE
> >
> >         Attachments: patch-CAY-436.txt
> >
> >
> > Should be good to change default delete rules for object relationships,
> one to many - cascade, and vice versa - to nullify. I think it's the rules
> used mostly for these relationships.
> > And the best thing would be to have configurable options for these, but
> that's more complex.
>
>
> --
> This message is automatically generated by JIRA.
> -
> You can reply to this email to add a comment to the issue online.
>
>

[nirvdrum]

I'm willing to go with this for now because the "manual" approach is  
fairly short and straightforward.  While what I proposed may (or may not)  
be more architecturally sound, it would certainly be more complicated.  
I'd still keep that part of code in mind as a candidate refactoring as you  
work through other issues that may have similar needs.

--
Kevin

On Mon, 30 Jun 2008 01:54:07 -0400, Andrey Razumovsky  
<razumovsky.andrey@...> wrote:

> The first and obvious reason was to use 'common' callbacks - like
> EntityListener and DataMapListener. But that would really make life  
> harder
> because I need not change the rule every time. For instance, I probably
> don't wan't to mess with it when I will code copy-paste. Finally, as  
> long as
> I remember, 'add' events are not fired sometimes (for instance, when
> syncronizing Db and Obj entities.
> Other rule for me was not to break into main core. Def rules are likely
> modeler's property and jdk-1.5-unpublished need not know about them. So I
> ended in manually checking all the places where a new relationship is
> created.
> To answer directly to your question, now I see that EntityMergeListener  
> can
> work in DbLoader if we add the same API to work with EntityMergeListeners
> and then pass them to EntityMergeSupport. Still, there's DbLoaderHelper.  
> I
> need to save entities to an array first because it comes to the helper
> without any relationships yet synchronized.
>
> 2008/6/30, Kevin Menard (JIRA) <dev@...>:
>>
>>
>>     [
>> https://issues.apache.org/cayenne/browse/CAY-436?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12986#action_12986]
>>
>> Kevin Menard commented on CAY-436:
>> ----------------------------------
>>
>> All in all, this looks pretty good.  A couple questions:
>>
>> 1) In DbLoaderHelper, is there any reason that you need to explicitly
>> update the ObjEntity?  Or rather, is there a reason that your observer
>> pattern fails to work here?
>>
>> 2) Is there a reason that the observer pattern fails in
>> ObjRelationshipInfoModel#savePath?
>>
>> I may be looking at the code wrong, but it strikes me that the
>> EntityMergeListener or something similar could be used in such a way  
>> that
>> you don't actually have to hook in explicit updates in so many places.
>>
>> > In modeler, change default object relationship delete rule
>> > ----------------------------------------------------------
>> >
>> >                 Key: CAY-436
>> >                 URL: https://issues.apache.org/cayenne/browse/CAY-436
>> >             Project: Cayenne
>> >          Issue Type: Improvement
>> >          Components: Cayenne Core Library, CayenneModeler GUI
>> >         Environment: winxp, M7
>> >            Reporter: weidox
>> >            Assignee: Kevin Menard
>> >             Fix For: UNDEFINED FUTURE
>> >
>> >         Attachments: patch-CAY-436.txt
>> >
>> >
>> > Should be good to change default delete rules for object  
>> relationships,
>> one to many - cascade, and vice versa - to nullify. I think it's the  
>> rules
>> used mostly for these relationships.
>> > And the best thing would be to have configurable options for these,  
>> but
>> that's more complex.
>>
>>
>> --
>> This message is automatically generated by JIRA.
>> -
>> You can reply to this email to add a comment to the issue online.
>>
>>