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Posted to users@openjpa.apache.org by Lukas Weibel <lu...@bluewin.ch> on 2009/02/04 14:58:59 UTC
Global (session-based) data filter
Hi there,
is there any global Datafilter with OpenJPA available? I want do delete
objects just logical (set a delete flag). For some sessions I want to
display only the active objects, but in other sessions the deleted ones
should also be displayed. Another case would be some security level on
each entity. The user can than only view objects that are in his
security level. Of course the filter should also apply for navigating in
the object model: group.getMembers() should only return objects
according to the current (session) filter.
Has anyone an idea how to solve this problem?
Hibernate does have such a mechano. But you have to apply the filter on
each association.
Regards,
Lukas Weibel
Re: Global (session-based) data filter
Posted by Steven Eckert <te...@hispeed.ch>.
Hi,
I'm currently having the same problem as you and with Hibernate. All my
entities in the database have a deleted flag. When loading from the
database, I want to filter all deleted entries. The only possibility I've
found is to add the filter to each entity (does not work when adding to base
class) and to each association. This is very error prone and hard to
maintain.
Is there no other way to define the filter on the base class, which is used
whenever a specialization is loaded? As well for each entity as well as for
the associations? Is Hibernate my problem?
Please let me know, if you find a solution!
Regards,
Steven
Lukas Weibel wrote:
>
> Hi there,
>
> is there any global Datafilter with OpenJPA available? I want do delete
> objects just logical (set a delete flag). For some sessions I want to
> display only the active objects, but in other sessions the deleted ones
> should also be displayed. Another case would be some security level on
> each entity. The user can than only view objects that are in his
> security level. Of course the filter should also apply for navigating in
> the object model: group.getMembers() should only return objects
> according to the current (session) filter.
>
> Has anyone an idea how to solve this problem?
>
> Hibernate does have such a mechano. But you have to apply the filter on
> each association.
>
> Regards,
> Lukas Weibel
>
>
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Re: Global (session-based) data filter
Posted by mysakjs <my...@us.ibm.com>.
Hi all, Just want to confirm whether this support is available now with
relatively current releases, including the latest, of openjpa. I am most
interested in this support to filter soft deleted records.
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Re: Global (session-based) data filter
Posted by Lukas Weibel <lu...@bluewin.ch>.
Hi all
Actually, I would prefer a filter set on the entity that would apply for all
operations on entities of that type…
Something like:
The sample entity (base class for all security relevant classes):
@Filter(name="accessLevel", condition=":current > accessLevel")
public class SampleClass {
private int accessLevel;
...
}
The access snippet:
EntityManagerFactory emf =
Persistence.createEntityManagerFactory("Tutorial");
EntityManager em = emf.createEntityManager();
em.enableFilter(accessLevel, new FilterArgument("current",
user.getAccessLevel())) ;
- Any JPQL Statement implicitly ignores objects that matches the filter
- Loading of objects and associations also ignores them.
em.disableFilter(accessLevel);
Of course changing a filter would require to clear the cache…
The soft-delete problem can be formulated as “@Filter(name="deleted",
condition="deleted=1")”. For deleting an object I would still use just an
update statement. Or the better, JPA should support an “@InsteadOfDelete”
callback…
Regards,
Lukas
Steven Eckert wrote:
>
> Hi Pinaki
>
> Thank you for your quick reply. I'd implement the soft delete with two
> distinct functionalities.
>
> The first would be to enhance the FilterDef. I'd add an inherit flag and a
> includeReference flag . E.g. @FilterDef(name = "isDeletedFilter",
> defaultCondition = "deleted = 0", inherit = "true", includeReference =
> "true"). This would allow me to define a filter on the base class (due to
> the inherit flag), which would be valid for all subclasses. The
> includeReference would indicate, thatloading a OneToMany inheritance, for
> the Many entities this filter is active.
>
> The second would be to add a BeforeDelete handler. This would be the same
> as the OnDelete but would return a boolean, if the entry should physically
> be deleted or not.
>
> The soft delete would be implemented by
> - Adding a FilterDef and defining a filter on the base class as described
> above with inherit = "true" and includeReference = "true". This would
> ensure, that any entities, marked as deleted would not be loaded. Either
> as Entity or as foreign key reference.
> - Creating a BeforeDelete handler, that "deletes" the Entity (by updating
> the Entry to be deleted and setting the deleted flag to true) and return
> false. This ensures the when a delete occurs, the entry is not physically
> deleted and it is marked as deleted.
>
> Please give me your view on this topic.
>
>
> Regards,
>
> Steven
>
>
> Pinaki Poddar wrote:
>>
>> Hi,
>>> is there any global Datafilter with OpenJPA available?
>>
>> This is an often requested feature, especially filter out 'softly
>> deleted' records. Also to filter multi-cardinality relations. But OpenJPA
>> does not (yet) have it.
>> Your requirements mention a more dynamic behavior. For example, in
>> some cases you want to access the softly deleted records, in some cases
>> you don't. Some filters are based on current user's security level. Few
>> of the inputs we will like to receive are
>>
>> a) what are the appropriate mechanics to describe the filter?
>> Class-level Annotations, Fetch Plan or a separate interface, query hints,
>> ....?
>> b) at what level such a filter should apply? Class, Field, both?
>> c) What is the syntax for the filter description?
>>
>> Let us know, with a concrete example how you will like to specify
>> the logical delete use case.
>>
>> Pinaki
>>
>
>
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Re: Global (session-based) data filter
Posted by Steven Eckert <te...@hispeed.ch>.
Hi Pinaki
Thank you for your quick reply. I'd implement the soft delete with two
distinct functionalities.
The first would be to enhance the FilterDef. I'd add an inherit flag and a
includeReference flag . E.g. @FilterDef(name = "isDeletedFilter",
defaultCondition = "deleted = 0", inherit = "true", includeReference =
"true"). This would allow me to define a filter on the base class (due to
the inherit flag), which would be valid for all subclasses. The
includeReference would indicate, thatloading a OneToMany inheritance, for
the Many entities this filter is active.
The second would be to add a BeforeDelete handler. This would be the same as
the OnDelete but would return a boolean, if the entry should physically be
deleted or not.
The soft delete would be implemented by
- Adding a FilterDef and defining a filter on the base class as described
above with inherit = "true" and includeReference = "true". This would
ensure, that any entities, marked as deleted would not be loaded. Either as
Entity or as foreign key reference.
- Creating a BeforeDelete handler, that "deletes" the Entity (by updating
the Entry to be deleted and setting the deleted flag to true) and return
false. This ensures the when a delete occurs, the entry is not physically
deleted and it is marked as deleted.
Please give me your view on this topic.
Regards,
Steven
Pinaki Poddar wrote:
>
> Hi,
>> is there any global Datafilter with OpenJPA available?
>
> This is an often requested feature, especially filter out 'softly
> deleted' records. Also to filter multi-cardinality relations. But OpenJPA
> does not (yet) have it.
> Your requirements mention a more dynamic behavior. For example, in some
> cases you want to access the softly deleted records, in some cases you
> don't. Some filters are based on current user's security level. Few of the
> inputs we will like to receive are
>
> a) what are the appropriate mechanics to describe the filter?
> Class-level Annotations, Fetch Plan or a separate interface, query hints,
> ....?
> b) at what level such a filter should apply? Class, Field, both?
> c) What is the syntax for the filter description?
>
> Let us know, with a concrete example how you will like to specify
> the logical delete use case.
>
> Pinaki
>
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Re: Global (session-based) data filter
Posted by Pinaki Poddar <pp...@apache.org>.
Hi,
> is there any global Datafilter with OpenJPA available?
This is an often requested feature, especially filter out 'softly deleted'
records. Also to filter multi-cardinality relations. But OpenJPA does not
(yet) have it.
Your requirements mention a more dynamic behavior. For example, in some
cases you want to access the softly deleted records, in some cases you
don't. Some filters are based on current user's security level. Few of the
inputs we will like to receive are
a) what are the appropriate mechanics to describe the filter? Class-level
Annotations, Fetch Plan or a separate interface, query hints, ....?
b) at what level such a filter should apply? Class, Field, both?
c) What is the syntax for the filter description?
Let us know, with a concrete example how you will like to specify the
logical delete use case.
Pinaki
--
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