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Posted to user@cayenne.apache.org by "Juan J. Gil" <ma...@gmail.com> on 2012/08/26 16:15:12 UTC
Vaadin Integration and MetaData of mappings
Hello, I'm thinking to use cayenne in conjunction with vaadin
(http://vaadin.com).
I'm trying to use some kind of tight integration between both frameworks
(defining cayenne generated classes which are vaadin data models
implementations).
That way I could define forms directly on data objects, querying &
mutating its state directly from vaadin widgets.
As vaadin is an stateful web framework, should I have to expect for some
kind of problem with data objects between requests? I mean, the data
objects will reside at the http session, and will be used directly by
the vaadin widgets, does this kind of cayenne data objects "use" could
arrive with attaching/detaching problems?
Also, is there a way to add metadata info in cayenne metamodel? I would
like to add constraints / validations to generated classes, so they can
be used to define searching criterias on indexed attributes (something
like active-records class filters, but only on indexed properties) and
generate model validations on properties so they can be used at UI
fields directly, facilitating the app development.
Finally, I'm looking for a multitenant implementation to use, and I
believe that the solution pointed at
http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/
could be also used with cayenne; is there any constraint I should look for?
Best regards
Juanjo
ps: pardon my really poor English! :P
Re: Vaadin Integration and MetaData of mappings
Posted by Andrus Adamchik <an...@objectstyle.org>.
Send us a link, when you do :)
On Aug 30, 2012, at 6:49 PM, Juan José Gil wrote:
> sorry, where says "bog" its "blog" :S
>
> 2012/8/30 Juan José Gil <ma...@gmail.com>
>
>> Understood :)
>>
>> Thanks for such great guidelines!
>>
>> I'll see if it is possible to bog about vaadin & cayenne integration :)
>>
>> Regards
>> Juanjo
>>
>> 2012/8/30 Andrus Adamchik <an...@objectstyle.org>
>>
>>> In your app please keep using Guice.
>>>
>>> Cayenne DI (which is strongly inspired by Guice, but has much smaller
>>> footprint) is intended for configuring stuff inside Cayenne. The container
>>> itself is hidden inside CayenneRuntime and we are not promoting it for
>>> general app-level use, even though in theory it should be possible.
>>>
>>> Andrus
>>>
>>> On Aug 30, 2012, at 4:13 PM, Juan José Gil wrote:
>>>
>>>> thanks Andrus!
>>>>
>>>> I'll give it a try :)
>>>>
>>>> which are the pros of using cayenne di instead of guice? (I've already
>>>> worked on integrating guice + vaadin + shiro and I don't want to loose
>>> all
>>>> that effort :S)
>>>>
>>>> Regards
>>>> Juanjo
>>>>
>>>>
>>>> 2012/8/30 Andrus Adamchik <an...@objectstyle.org>
>>>>
>>>>> 1. Serialization. There's not much to it really. Just make sure the
>>>>> context you are using is session-scoped. See for instance this class
>>> that
>>>>> provides a session-bound context (used by CayenneFilter) :
>>>>>
>>>>>
>>>>>
>>> http://svn.apache.org/viewvc/cayenne/main/branches/STABLE-3.1/framework/cayenne-jdk1.5-unpublished/src/main/java/org/apache/cayenne/configuration/web/SessionContextRequestHandler.java?view=markup
>>>>>
>>>>> 2. Multi-tenancy... So if you go with DB-schema per tenant, it might
>>> look
>>>>> like this:
>>>>>
>>>>> // do it once per tenant, and cache the returned runtime in the app
>>> scope
>>>>> ServerRuntime createServerRuntime(final String tenantSchema) {
>>>>>
>>>>> // "cayenne-xyz.xml" is a mapping common to all tenants, that will be
>>>>> further customized here
>>>>> ServerRuntime runtime = new ServerRuntime("cayenne-xyz.xml", new
>>>>> Module() {
>>>>>
>>>>> // in a custom module override the schema of all loaded DataMaps
>>>>> public void configure(Binder binder) {
>>>>> binder.bind(DataMapLoader.class).toInstance(new
>>>>> TenantMapLoader(tenantSchema));
>>>>> }
>>>>> });
>>>>>
>>>>>
>>>>> return runtime;
>>>>> }
>>>>>
>>>>> class TenantMapLoader extends XMLDataMapLoader {
>>>>>
>>>>> private String tenantSchema;
>>>>>
>>>>> TenantMapLoader(String tenantSchema) {
>>>>> this.tenantSchema = tenantSchema;
>>>>> }
>>>>>
>>>>>
>>>>> public DataMap load(Resource configurationResource) {
>>>>> DataMap map = super.load(configurationResource);
>>>>> map.setDefaultSchema(tenantSchema);
>>>>>
>>>>> for(DbEntity e : map.getDbEntities()) {
>>>>> e.setSchema(tenantSchema);
>>>>> }
>>>>>
>>>>> return map;
>>>>> }
>>>>> }
>>>>>
>>>>> Andrus
>>>>>
>>>>>
>>>>> On Aug 29, 2012, at 4:15 PM, Juan José Gil wrote:
>>>>>
>>>>>> Thanks for the reply Andrus!
>>>>>>
>>>>>> Could you point me to docs/samples about ObjectContext Serialization &
>>>>>> multi-tenant approaches you describe?
>>>>>>
>>>>>> About the"adding-metadata" part, I was thinking in adding constraints
>>> in
>>>>> a
>>>>>> similar way to active-record in RoR or GORM in grails, but using code
>>>>>> generation phases of cayenne.
>>>>>>
>>>>>> By now i'll use some kind of "typed" KVC delegating to cayenne the
>>>>>> properties access and then providing some kind a "class metadata"
>>> which
>>>>> can
>>>>>> be extended by subclasses... but i'll prefer the "code generation"
>>> form,
>>>>> so
>>>>>> I can use IDEs capabilities.
>>>>>>
>>>>>> maybe I'll generate some "java code configuration" which then will be
>>>>> used
>>>>>> to generate final classes... it sounds as a mess but it could give
>>> really
>>>>>> nice possibilities! don't you think?
>>>>>>
>>>>>> if i get to somewhere with this approach I'll tell you :)
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> the data objects will reside at the http session, and will be used
>>>>>>> directly by the vaadin widgets, does this kind of cayenne data
>>> objects
>>>>>>> "use" could arrive with attaching/detaching problems?
>>>>>>>
>>>>>>> Shouldn't be a problem. You can store Cayenne objects in a session.
>>> The
>>>>>>> simplest way to avoid attach/detach issues is to have a
>>> session-scoped
>>>>>>> ObjectContext. Then it is serialized/deserialized together with the
>>>>> objects
>>>>>>> in case the session is saved to disk, or replicated across the
>>> cluster.
>>>>>>>
>>>>>>>> Also, is there a way to add metadata info in cayenne metamodel? I
>>> would
>>>>>>> like to add constraints / validations to generated classes, so they
>>> can
>>>>> be
>>>>>>> used to define searching criterias on indexed attributes (something
>>> like
>>>>>>> active-records class filters, but only on indexed properties) and
>>>>> generate
>>>>>>> model validations on properties so they can be used at UI fields
>>>>> directly,
>>>>>>> facilitating the app development.
>>>>>>>
>>>>>>> You can add extra info using callbacks or lifecycle listeners. Any
>>> extra
>>>>>>> properties can be defined either manually in generated subclasses, or
>>>>> even
>>>>>>> stored in the base CayenneDataObject (with 'readProperty' /
>>>>> 'writeProperty'
>>>>>>> methods, and custom property names).
>>>>>>>
>>>>>>>> Finally, I'm looking for a multitenant implementation to use, and I
>>>>>>> believe that the solution pointed at
>>>>>>>
>>>>>
>>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbealso used with cayenne; is there any constraint I should look for?
>>>>>>>
>>>>>>> Cayenne is certainly friendly to various multi-tenancy approaches. In
>>>>> 3.1
>>>>>>> API terms, you might assign a separate instance of ServerRuntime to
>>> each
>>>>>>> tenant, and use that to create ObjectContexts for its users. You may
>>>>> start
>>>>>>> all runtimes from the same basic configuration, and "namespace" them
>>>>> using
>>>>>>> tenant-unique DB URL. Or you may use a single DataSource, and after a
>>>>>>> runtime is loaded, scan through all its DbEntities and assign a
>>> tenant
>>>>>>> "schema" to them. Feel free to ask about further details.
>>>>>>>
>>>>>>> Andrus
>>>>>>>
>>>>>>>
>>>>>>> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
>>>>>>>> Hello, I'm thinking to use cayenne in conjunction with vaadin (
>>>>>>> http://vaadin.com).
>>>>>>>>
>>>>>>>> I'm trying to use some kind of tight integration between both
>>>>> frameworks
>>>>>>> (defining cayenne generated classes which are vaadin data models
>>>>>>> implementations).
>>>>>>>> That way I could define forms directly on data objects, querying &
>>>>>>> mutating its state directly from vaadin widgets.
>>>>>>>> As vaadin is an stateful web framework, should I have to expect for
>>>>> some
>>>>>>> kind of problem with data objects between requests? I mean, the data
>>>>>>> objects will reside at the http session, and will be used directly by
>>>>> the
>>>>>>> vaadin widgets, does this kind of cayenne data objects "use" could
>>>>> arrive
>>>>>>> with attaching/detaching problems?
>>>>>>>>
>>>>>>>> Also, is there a way to add metadata info in cayenne metamodel? I
>>> would
>>>>>>> like to add constraints / validations to generated classes, so they
>>> can
>>>>> be
>>>>>>> used to define searching criterias on indexed attributes (something
>>> like
>>>>>>> active-records class filters, but only on indexed properties) and
>>>>> generate
>>>>>>> model validations on properties so they can be used at UI fields
>>>>> directly,
>>>>>>> facilitating the app development.
>>>>>>>>
>>>>>>>> Finally, I'm looking for a multitenant implementation to use, and I
>>>>>>> believe that the solution pointed at
>>>>>>>
>>>>>
>>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbealso used with cayenne; is there any constraint I should look for?
>>>>>>>>
>>>>>>>> Best regards
>>>>>>>> Juanjo
>>>>>>>>
>>>>>>>> ps: pardon my really poor English! :P
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>
>>>
>>
Re: Vaadin Integration and MetaData of mappings
Posted by Juan José Gil <ma...@gmail.com>.
sorry, where says "bog" its "blog" :S
2012/8/30 Juan José Gil <ma...@gmail.com>
> Understood :)
>
> Thanks for such great guidelines!
>
> I'll see if it is possible to bog about vaadin & cayenne integration :)
>
> Regards
> Juanjo
>
> 2012/8/30 Andrus Adamchik <an...@objectstyle.org>
>
>> In your app please keep using Guice.
>>
>> Cayenne DI (which is strongly inspired by Guice, but has much smaller
>> footprint) is intended for configuring stuff inside Cayenne. The container
>> itself is hidden inside CayenneRuntime and we are not promoting it for
>> general app-level use, even though in theory it should be possible.
>>
>> Andrus
>>
>> On Aug 30, 2012, at 4:13 PM, Juan José Gil wrote:
>>
>> > thanks Andrus!
>> >
>> > I'll give it a try :)
>> >
>> > which are the pros of using cayenne di instead of guice? (I've already
>> > worked on integrating guice + vaadin + shiro and I don't want to loose
>> all
>> > that effort :S)
>> >
>> > Regards
>> > Juanjo
>> >
>> >
>> > 2012/8/30 Andrus Adamchik <an...@objectstyle.org>
>> >
>> >> 1. Serialization. There's not much to it really. Just make sure the
>> >> context you are using is session-scoped. See for instance this class
>> that
>> >> provides a session-bound context (used by CayenneFilter) :
>> >>
>> >>
>> >>
>> http://svn.apache.org/viewvc/cayenne/main/branches/STABLE-3.1/framework/cayenne-jdk1.5-unpublished/src/main/java/org/apache/cayenne/configuration/web/SessionContextRequestHandler.java?view=markup
>> >>
>> >> 2. Multi-tenancy... So if you go with DB-schema per tenant, it might
>> look
>> >> like this:
>> >>
>> >> // do it once per tenant, and cache the returned runtime in the app
>> scope
>> >> ServerRuntime createServerRuntime(final String tenantSchema) {
>> >>
>> >> // "cayenne-xyz.xml" is a mapping common to all tenants, that will be
>> >> further customized here
>> >> ServerRuntime runtime = new ServerRuntime("cayenne-xyz.xml", new
>> >> Module() {
>> >>
>> >> // in a custom module override the schema of all loaded DataMaps
>> >> public void configure(Binder binder) {
>> >> binder.bind(DataMapLoader.class).toInstance(new
>> >> TenantMapLoader(tenantSchema));
>> >> }
>> >> });
>> >>
>> >>
>> >> return runtime;
>> >> }
>> >>
>> >> class TenantMapLoader extends XMLDataMapLoader {
>> >>
>> >> private String tenantSchema;
>> >>
>> >> TenantMapLoader(String tenantSchema) {
>> >> this.tenantSchema = tenantSchema;
>> >> }
>> >>
>> >>
>> >> public DataMap load(Resource configurationResource) {
>> >> DataMap map = super.load(configurationResource);
>> >> map.setDefaultSchema(tenantSchema);
>> >>
>> >> for(DbEntity e : map.getDbEntities()) {
>> >> e.setSchema(tenantSchema);
>> >> }
>> >>
>> >> return map;
>> >> }
>> >> }
>> >>
>> >> Andrus
>> >>
>> >>
>> >> On Aug 29, 2012, at 4:15 PM, Juan José Gil wrote:
>> >>
>> >>> Thanks for the reply Andrus!
>> >>>
>> >>> Could you point me to docs/samples about ObjectContext Serialization &
>> >>> multi-tenant approaches you describe?
>> >>>
>> >>> About the"adding-metadata" part, I was thinking in adding constraints
>> in
>> >> a
>> >>> similar way to active-record in RoR or GORM in grails, but using code
>> >>> generation phases of cayenne.
>> >>>
>> >>> By now i'll use some kind of "typed" KVC delegating to cayenne the
>> >>> properties access and then providing some kind a "class metadata"
>> which
>> >> can
>> >>> be extended by subclasses... but i'll prefer the "code generation"
>> form,
>> >> so
>> >>> I can use IDEs capabilities.
>> >>>
>> >>> maybe I'll generate some "java code configuration" which then will be
>> >> used
>> >>> to generate final classes... it sounds as a mess but it could give
>> really
>> >>> nice possibilities! don't you think?
>> >>>
>> >>> if i get to somewhere with this approach I'll tell you :)
>> >>>
>> >>>>
>> >>>>
>> >>>>> the data objects will reside at the http session, and will be used
>> >>>> directly by the vaadin widgets, does this kind of cayenne data
>> objects
>> >>>> "use" could arrive with attaching/detaching problems?
>> >>>>
>> >>>> Shouldn't be a problem. You can store Cayenne objects in a session.
>> The
>> >>>> simplest way to avoid attach/detach issues is to have a
>> session-scoped
>> >>>> ObjectContext. Then it is serialized/deserialized together with the
>> >> objects
>> >>>> in case the session is saved to disk, or replicated across the
>> cluster.
>> >>>>
>> >>>>> Also, is there a way to add metadata info in cayenne metamodel? I
>> would
>> >>>> like to add constraints / validations to generated classes, so they
>> can
>> >> be
>> >>>> used to define searching criterias on indexed attributes (something
>> like
>> >>>> active-records class filters, but only on indexed properties) and
>> >> generate
>> >>>> model validations on properties so they can be used at UI fields
>> >> directly,
>> >>>> facilitating the app development.
>> >>>>
>> >>>> You can add extra info using callbacks or lifecycle listeners. Any
>> extra
>> >>>> properties can be defined either manually in generated subclasses, or
>> >> even
>> >>>> stored in the base CayenneDataObject (with 'readProperty' /
>> >> 'writeProperty'
>> >>>> methods, and custom property names).
>> >>>>
>> >>>>> Finally, I'm looking for a multitenant implementation to use, and I
>> >>>> believe that the solution pointed at
>> >>>>
>> >>
>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbealso used with cayenne; is there any constraint I should look for?
>> >>>>
>> >>>> Cayenne is certainly friendly to various multi-tenancy approaches. In
>> >> 3.1
>> >>>> API terms, you might assign a separate instance of ServerRuntime to
>> each
>> >>>> tenant, and use that to create ObjectContexts for its users. You may
>> >> start
>> >>>> all runtimes from the same basic configuration, and "namespace" them
>> >> using
>> >>>> tenant-unique DB URL. Or you may use a single DataSource, and after a
>> >>>> runtime is loaded, scan through all its DbEntities and assign a
>> tenant
>> >>>> "schema" to them. Feel free to ask about further details.
>> >>>>
>> >>>> Andrus
>> >>>>
>> >>>>
>> >>>> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
>> >>>>> Hello, I'm thinking to use cayenne in conjunction with vaadin (
>> >>>> http://vaadin.com).
>> >>>>>
>> >>>>> I'm trying to use some kind of tight integration between both
>> >> frameworks
>> >>>> (defining cayenne generated classes which are vaadin data models
>> >>>> implementations).
>> >>>>> That way I could define forms directly on data objects, querying &
>> >>>> mutating its state directly from vaadin widgets.
>> >>>>> As vaadin is an stateful web framework, should I have to expect for
>> >> some
>> >>>> kind of problem with data objects between requests? I mean, the data
>> >>>> objects will reside at the http session, and will be used directly by
>> >> the
>> >>>> vaadin widgets, does this kind of cayenne data objects "use" could
>> >> arrive
>> >>>> with attaching/detaching problems?
>> >>>>>
>> >>>>> Also, is there a way to add metadata info in cayenne metamodel? I
>> would
>> >>>> like to add constraints / validations to generated classes, so they
>> can
>> >> be
>> >>>> used to define searching criterias on indexed attributes (something
>> like
>> >>>> active-records class filters, but only on indexed properties) and
>> >> generate
>> >>>> model validations on properties so they can be used at UI fields
>> >> directly,
>> >>>> facilitating the app development.
>> >>>>>
>> >>>>> Finally, I'm looking for a multitenant implementation to use, and I
>> >>>> believe that the solution pointed at
>> >>>>
>> >>
>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbealso used with cayenne; is there any constraint I should look for?
>> >>>>>
>> >>>>> Best regards
>> >>>>> Juanjo
>> >>>>>
>> >>>>> ps: pardon my really poor English! :P
>> >>>>>
>> >>>>>
>> >>>>
>> >>>>
>> >>
>> >>
>>
>>
>
Re: Vaadin Integration and MetaData of mappings
Posted by Juan José Gil <ma...@gmail.com>.
Understood :)
Thanks for such great guidelines!
I'll see if it is possible to bog about vaadin & cayenne integration :)
Regards
Juanjo
2012/8/30 Andrus Adamchik <an...@objectstyle.org>
> In your app please keep using Guice.
>
> Cayenne DI (which is strongly inspired by Guice, but has much smaller
> footprint) is intended for configuring stuff inside Cayenne. The container
> itself is hidden inside CayenneRuntime and we are not promoting it for
> general app-level use, even though in theory it should be possible.
>
> Andrus
>
> On Aug 30, 2012, at 4:13 PM, Juan José Gil wrote:
>
> > thanks Andrus!
> >
> > I'll give it a try :)
> >
> > which are the pros of using cayenne di instead of guice? (I've already
> > worked on integrating guice + vaadin + shiro and I don't want to loose
> all
> > that effort :S)
> >
> > Regards
> > Juanjo
> >
> >
> > 2012/8/30 Andrus Adamchik <an...@objectstyle.org>
> >
> >> 1. Serialization. There's not much to it really. Just make sure the
> >> context you are using is session-scoped. See for instance this class
> that
> >> provides a session-bound context (used by CayenneFilter) :
> >>
> >>
> >>
> http://svn.apache.org/viewvc/cayenne/main/branches/STABLE-3.1/framework/cayenne-jdk1.5-unpublished/src/main/java/org/apache/cayenne/configuration/web/SessionContextRequestHandler.java?view=markup
> >>
> >> 2. Multi-tenancy... So if you go with DB-schema per tenant, it might
> look
> >> like this:
> >>
> >> // do it once per tenant, and cache the returned runtime in the app
> scope
> >> ServerRuntime createServerRuntime(final String tenantSchema) {
> >>
> >> // "cayenne-xyz.xml" is a mapping common to all tenants, that will be
> >> further customized here
> >> ServerRuntime runtime = new ServerRuntime("cayenne-xyz.xml", new
> >> Module() {
> >>
> >> // in a custom module override the schema of all loaded DataMaps
> >> public void configure(Binder binder) {
> >> binder.bind(DataMapLoader.class).toInstance(new
> >> TenantMapLoader(tenantSchema));
> >> }
> >> });
> >>
> >>
> >> return runtime;
> >> }
> >>
> >> class TenantMapLoader extends XMLDataMapLoader {
> >>
> >> private String tenantSchema;
> >>
> >> TenantMapLoader(String tenantSchema) {
> >> this.tenantSchema = tenantSchema;
> >> }
> >>
> >>
> >> public DataMap load(Resource configurationResource) {
> >> DataMap map = super.load(configurationResource);
> >> map.setDefaultSchema(tenantSchema);
> >>
> >> for(DbEntity e : map.getDbEntities()) {
> >> e.setSchema(tenantSchema);
> >> }
> >>
> >> return map;
> >> }
> >> }
> >>
> >> Andrus
> >>
> >>
> >> On Aug 29, 2012, at 4:15 PM, Juan José Gil wrote:
> >>
> >>> Thanks for the reply Andrus!
> >>>
> >>> Could you point me to docs/samples about ObjectContext Serialization &
> >>> multi-tenant approaches you describe?
> >>>
> >>> About the"adding-metadata" part, I was thinking in adding constraints
> in
> >> a
> >>> similar way to active-record in RoR or GORM in grails, but using code
> >>> generation phases of cayenne.
> >>>
> >>> By now i'll use some kind of "typed" KVC delegating to cayenne the
> >>> properties access and then providing some kind a "class metadata" which
> >> can
> >>> be extended by subclasses... but i'll prefer the "code generation"
> form,
> >> so
> >>> I can use IDEs capabilities.
> >>>
> >>> maybe I'll generate some "java code configuration" which then will be
> >> used
> >>> to generate final classes... it sounds as a mess but it could give
> really
> >>> nice possibilities! don't you think?
> >>>
> >>> if i get to somewhere with this approach I'll tell you :)
> >>>
> >>>>
> >>>>
> >>>>> the data objects will reside at the http session, and will be used
> >>>> directly by the vaadin widgets, does this kind of cayenne data objects
> >>>> "use" could arrive with attaching/detaching problems?
> >>>>
> >>>> Shouldn't be a problem. You can store Cayenne objects in a session.
> The
> >>>> simplest way to avoid attach/detach issues is to have a session-scoped
> >>>> ObjectContext. Then it is serialized/deserialized together with the
> >> objects
> >>>> in case the session is saved to disk, or replicated across the
> cluster.
> >>>>
> >>>>> Also, is there a way to add metadata info in cayenne metamodel? I
> would
> >>>> like to add constraints / validations to generated classes, so they
> can
> >> be
> >>>> used to define searching criterias on indexed attributes (something
> like
> >>>> active-records class filters, but only on indexed properties) and
> >> generate
> >>>> model validations on properties so they can be used at UI fields
> >> directly,
> >>>> facilitating the app development.
> >>>>
> >>>> You can add extra info using callbacks or lifecycle listeners. Any
> extra
> >>>> properties can be defined either manually in generated subclasses, or
> >> even
> >>>> stored in the base CayenneDataObject (with 'readProperty' /
> >> 'writeProperty'
> >>>> methods, and custom property names).
> >>>>
> >>>>> Finally, I'm looking for a multitenant implementation to use, and I
> >>>> believe that the solution pointed at
> >>>>
> >>
> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbealso used with cayenne; is there any constraint I should look for?
> >>>>
> >>>> Cayenne is certainly friendly to various multi-tenancy approaches. In
> >> 3.1
> >>>> API terms, you might assign a separate instance of ServerRuntime to
> each
> >>>> tenant, and use that to create ObjectContexts for its users. You may
> >> start
> >>>> all runtimes from the same basic configuration, and "namespace" them
> >> using
> >>>> tenant-unique DB URL. Or you may use a single DataSource, and after a
> >>>> runtime is loaded, scan through all its DbEntities and assign a tenant
> >>>> "schema" to them. Feel free to ask about further details.
> >>>>
> >>>> Andrus
> >>>>
> >>>>
> >>>> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
> >>>>> Hello, I'm thinking to use cayenne in conjunction with vaadin (
> >>>> http://vaadin.com).
> >>>>>
> >>>>> I'm trying to use some kind of tight integration between both
> >> frameworks
> >>>> (defining cayenne generated classes which are vaadin data models
> >>>> implementations).
> >>>>> That way I could define forms directly on data objects, querying &
> >>>> mutating its state directly from vaadin widgets.
> >>>>> As vaadin is an stateful web framework, should I have to expect for
> >> some
> >>>> kind of problem with data objects between requests? I mean, the data
> >>>> objects will reside at the http session, and will be used directly by
> >> the
> >>>> vaadin widgets, does this kind of cayenne data objects "use" could
> >> arrive
> >>>> with attaching/detaching problems?
> >>>>>
> >>>>> Also, is there a way to add metadata info in cayenne metamodel? I
> would
> >>>> like to add constraints / validations to generated classes, so they
> can
> >> be
> >>>> used to define searching criterias on indexed attributes (something
> like
> >>>> active-records class filters, but only on indexed properties) and
> >> generate
> >>>> model validations on properties so they can be used at UI fields
> >> directly,
> >>>> facilitating the app development.
> >>>>>
> >>>>> Finally, I'm looking for a multitenant implementation to use, and I
> >>>> believe that the solution pointed at
> >>>>
> >>
> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbealso used with cayenne; is there any constraint I should look for?
> >>>>>
> >>>>> Best regards
> >>>>> Juanjo
> >>>>>
> >>>>> ps: pardon my really poor English! :P
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>
> >>
>
>
Re: Vaadin Integration and MetaData of mappings
Posted by Andrus Adamchik <an...@objectstyle.org>.
In your app please keep using Guice.
Cayenne DI (which is strongly inspired by Guice, but has much smaller footprint) is intended for configuring stuff inside Cayenne. The container itself is hidden inside CayenneRuntime and we are not promoting it for general app-level use, even though in theory it should be possible.
Andrus
On Aug 30, 2012, at 4:13 PM, Juan José Gil wrote:
> thanks Andrus!
>
> I'll give it a try :)
>
> which are the pros of using cayenne di instead of guice? (I've already
> worked on integrating guice + vaadin + shiro and I don't want to loose all
> that effort :S)
>
> Regards
> Juanjo
>
>
> 2012/8/30 Andrus Adamchik <an...@objectstyle.org>
>
>> 1. Serialization. There's not much to it really. Just make sure the
>> context you are using is session-scoped. See for instance this class that
>> provides a session-bound context (used by CayenneFilter) :
>>
>>
>> http://svn.apache.org/viewvc/cayenne/main/branches/STABLE-3.1/framework/cayenne-jdk1.5-unpublished/src/main/java/org/apache/cayenne/configuration/web/SessionContextRequestHandler.java?view=markup
>>
>> 2. Multi-tenancy... So if you go with DB-schema per tenant, it might look
>> like this:
>>
>> // do it once per tenant, and cache the returned runtime in the app scope
>> ServerRuntime createServerRuntime(final String tenantSchema) {
>>
>> // "cayenne-xyz.xml" is a mapping common to all tenants, that will be
>> further customized here
>> ServerRuntime runtime = new ServerRuntime("cayenne-xyz.xml", new
>> Module() {
>>
>> // in a custom module override the schema of all loaded DataMaps
>> public void configure(Binder binder) {
>> binder.bind(DataMapLoader.class).toInstance(new
>> TenantMapLoader(tenantSchema));
>> }
>> });
>>
>>
>> return runtime;
>> }
>>
>> class TenantMapLoader extends XMLDataMapLoader {
>>
>> private String tenantSchema;
>>
>> TenantMapLoader(String tenantSchema) {
>> this.tenantSchema = tenantSchema;
>> }
>>
>>
>> public DataMap load(Resource configurationResource) {
>> DataMap map = super.load(configurationResource);
>> map.setDefaultSchema(tenantSchema);
>>
>> for(DbEntity e : map.getDbEntities()) {
>> e.setSchema(tenantSchema);
>> }
>>
>> return map;
>> }
>> }
>>
>> Andrus
>>
>>
>> On Aug 29, 2012, at 4:15 PM, Juan José Gil wrote:
>>
>>> Thanks for the reply Andrus!
>>>
>>> Could you point me to docs/samples about ObjectContext Serialization &
>>> multi-tenant approaches you describe?
>>>
>>> About the"adding-metadata" part, I was thinking in adding constraints in
>> a
>>> similar way to active-record in RoR or GORM in grails, but using code
>>> generation phases of cayenne.
>>>
>>> By now i'll use some kind of "typed" KVC delegating to cayenne the
>>> properties access and then providing some kind a "class metadata" which
>> can
>>> be extended by subclasses... but i'll prefer the "code generation" form,
>> so
>>> I can use IDEs capabilities.
>>>
>>> maybe I'll generate some "java code configuration" which then will be
>> used
>>> to generate final classes... it sounds as a mess but it could give really
>>> nice possibilities! don't you think?
>>>
>>> if i get to somewhere with this approach I'll tell you :)
>>>
>>>>
>>>>
>>>>> the data objects will reside at the http session, and will be used
>>>> directly by the vaadin widgets, does this kind of cayenne data objects
>>>> "use" could arrive with attaching/detaching problems?
>>>>
>>>> Shouldn't be a problem. You can store Cayenne objects in a session. The
>>>> simplest way to avoid attach/detach issues is to have a session-scoped
>>>> ObjectContext. Then it is serialized/deserialized together with the
>> objects
>>>> in case the session is saved to disk, or replicated across the cluster.
>>>>
>>>>> Also, is there a way to add metadata info in cayenne metamodel? I would
>>>> like to add constraints / validations to generated classes, so they can
>> be
>>>> used to define searching criterias on indexed attributes (something like
>>>> active-records class filters, but only on indexed properties) and
>> generate
>>>> model validations on properties so they can be used at UI fields
>> directly,
>>>> facilitating the app development.
>>>>
>>>> You can add extra info using callbacks or lifecycle listeners. Any extra
>>>> properties can be defined either manually in generated subclasses, or
>> even
>>>> stored in the base CayenneDataObject (with 'readProperty' /
>> 'writeProperty'
>>>> methods, and custom property names).
>>>>
>>>>> Finally, I'm looking for a multitenant implementation to use, and I
>>>> believe that the solution pointed at
>>>>
>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbe also used with cayenne; is there any constraint I should look for?
>>>>
>>>> Cayenne is certainly friendly to various multi-tenancy approaches. In
>> 3.1
>>>> API terms, you might assign a separate instance of ServerRuntime to each
>>>> tenant, and use that to create ObjectContexts for its users. You may
>> start
>>>> all runtimes from the same basic configuration, and "namespace" them
>> using
>>>> tenant-unique DB URL. Or you may use a single DataSource, and after a
>>>> runtime is loaded, scan through all its DbEntities and assign a tenant
>>>> "schema" to them. Feel free to ask about further details.
>>>>
>>>> Andrus
>>>>
>>>>
>>>> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
>>>>> Hello, I'm thinking to use cayenne in conjunction with vaadin (
>>>> http://vaadin.com).
>>>>>
>>>>> I'm trying to use some kind of tight integration between both
>> frameworks
>>>> (defining cayenne generated classes which are vaadin data models
>>>> implementations).
>>>>> That way I could define forms directly on data objects, querying &
>>>> mutating its state directly from vaadin widgets.
>>>>> As vaadin is an stateful web framework, should I have to expect for
>> some
>>>> kind of problem with data objects between requests? I mean, the data
>>>> objects will reside at the http session, and will be used directly by
>> the
>>>> vaadin widgets, does this kind of cayenne data objects "use" could
>> arrive
>>>> with attaching/detaching problems?
>>>>>
>>>>> Also, is there a way to add metadata info in cayenne metamodel? I would
>>>> like to add constraints / validations to generated classes, so they can
>> be
>>>> used to define searching criterias on indexed attributes (something like
>>>> active-records class filters, but only on indexed properties) and
>> generate
>>>> model validations on properties so they can be used at UI fields
>> directly,
>>>> facilitating the app development.
>>>>>
>>>>> Finally, I'm looking for a multitenant implementation to use, and I
>>>> believe that the solution pointed at
>>>>
>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbe also used with cayenne; is there any constraint I should look for?
>>>>>
>>>>> Best regards
>>>>> Juanjo
>>>>>
>>>>> ps: pardon my really poor English! :P
>>>>>
>>>>>
>>>>
>>>>
>>
>>
Re: Vaadin Integration and MetaData of mappings
Posted by Juan José Gil <ma...@gmail.com>.
thanks Andrus!
I'll give it a try :)
which are the pros of using cayenne di instead of guice? (I've already
worked on integrating guice + vaadin + shiro and I don't want to loose all
that effort :S)
Regards
Juanjo
2012/8/30 Andrus Adamchik <an...@objectstyle.org>
> 1. Serialization. There's not much to it really. Just make sure the
> context you are using is session-scoped. See for instance this class that
> provides a session-bound context (used by CayenneFilter) :
>
>
> http://svn.apache.org/viewvc/cayenne/main/branches/STABLE-3.1/framework/cayenne-jdk1.5-unpublished/src/main/java/org/apache/cayenne/configuration/web/SessionContextRequestHandler.java?view=markup
>
> 2. Multi-tenancy... So if you go with DB-schema per tenant, it might look
> like this:
>
> // do it once per tenant, and cache the returned runtime in the app scope
> ServerRuntime createServerRuntime(final String tenantSchema) {
>
> // "cayenne-xyz.xml" is a mapping common to all tenants, that will be
> further customized here
> ServerRuntime runtime = new ServerRuntime("cayenne-xyz.xml", new
> Module() {
>
> // in a custom module override the schema of all loaded DataMaps
> public void configure(Binder binder) {
> binder.bind(DataMapLoader.class).toInstance(new
> TenantMapLoader(tenantSchema));
> }
> });
>
>
> return runtime;
> }
>
> class TenantMapLoader extends XMLDataMapLoader {
>
> private String tenantSchema;
>
> TenantMapLoader(String tenantSchema) {
> this.tenantSchema = tenantSchema;
> }
>
>
> public DataMap load(Resource configurationResource) {
> DataMap map = super.load(configurationResource);
> map.setDefaultSchema(tenantSchema);
>
> for(DbEntity e : map.getDbEntities()) {
> e.setSchema(tenantSchema);
> }
>
> return map;
> }
> }
>
> Andrus
>
>
> On Aug 29, 2012, at 4:15 PM, Juan José Gil wrote:
>
> > Thanks for the reply Andrus!
> >
> > Could you point me to docs/samples about ObjectContext Serialization &
> > multi-tenant approaches you describe?
> >
> > About the"adding-metadata" part, I was thinking in adding constraints in
> a
> > similar way to active-record in RoR or GORM in grails, but using code
> > generation phases of cayenne.
> >
> > By now i'll use some kind of "typed" KVC delegating to cayenne the
> > properties access and then providing some kind a "class metadata" which
> can
> > be extended by subclasses... but i'll prefer the "code generation" form,
> so
> > I can use IDEs capabilities.
> >
> > maybe I'll generate some "java code configuration" which then will be
> used
> > to generate final classes... it sounds as a mess but it could give really
> > nice possibilities! don't you think?
> >
> > if i get to somewhere with this approach I'll tell you :)
> >
> >>
> >>
> >>> the data objects will reside at the http session, and will be used
> >> directly by the vaadin widgets, does this kind of cayenne data objects
> >> "use" could arrive with attaching/detaching problems?
> >>
> >> Shouldn't be a problem. You can store Cayenne objects in a session. The
> >> simplest way to avoid attach/detach issues is to have a session-scoped
> >> ObjectContext. Then it is serialized/deserialized together with the
> objects
> >> in case the session is saved to disk, or replicated across the cluster.
> >>
> >>> Also, is there a way to add metadata info in cayenne metamodel? I would
> >> like to add constraints / validations to generated classes, so they can
> be
> >> used to define searching criterias on indexed attributes (something like
> >> active-records class filters, but only on indexed properties) and
> generate
> >> model validations on properties so they can be used at UI fields
> directly,
> >> facilitating the app development.
> >>
> >> You can add extra info using callbacks or lifecycle listeners. Any extra
> >> properties can be defined either manually in generated subclasses, or
> even
> >> stored in the base CayenneDataObject (with 'readProperty' /
> 'writeProperty'
> >> methods, and custom property names).
> >>
> >>> Finally, I'm looking for a multitenant implementation to use, and I
> >> believe that the solution pointed at
> >>
> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbe also used with cayenne; is there any constraint I should look for?
> >>
> >> Cayenne is certainly friendly to various multi-tenancy approaches. In
> 3.1
> >> API terms, you might assign a separate instance of ServerRuntime to each
> >> tenant, and use that to create ObjectContexts for its users. You may
> start
> >> all runtimes from the same basic configuration, and "namespace" them
> using
> >> tenant-unique DB URL. Or you may use a single DataSource, and after a
> >> runtime is loaded, scan through all its DbEntities and assign a tenant
> >> "schema" to them. Feel free to ask about further details.
> >>
> >> Andrus
> >>
> >>
> >> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
> >>> Hello, I'm thinking to use cayenne in conjunction with vaadin (
> >> http://vaadin.com).
> >>>
> >>> I'm trying to use some kind of tight integration between both
> frameworks
> >> (defining cayenne generated classes which are vaadin data models
> >> implementations).
> >>> That way I could define forms directly on data objects, querying &
> >> mutating its state directly from vaadin widgets.
> >>> As vaadin is an stateful web framework, should I have to expect for
> some
> >> kind of problem with data objects between requests? I mean, the data
> >> objects will reside at the http session, and will be used directly by
> the
> >> vaadin widgets, does this kind of cayenne data objects "use" could
> arrive
> >> with attaching/detaching problems?
> >>>
> >>> Also, is there a way to add metadata info in cayenne metamodel? I would
> >> like to add constraints / validations to generated classes, so they can
> be
> >> used to define searching criterias on indexed attributes (something like
> >> active-records class filters, but only on indexed properties) and
> generate
> >> model validations on properties so they can be used at UI fields
> directly,
> >> facilitating the app development.
> >>>
> >>> Finally, I'm looking for a multitenant implementation to use, and I
> >> believe that the solution pointed at
> >>
> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/couldbe also used with cayenne; is there any constraint I should look for?
> >>>
> >>> Best regards
> >>> Juanjo
> >>>
> >>> ps: pardon my really poor English! :P
> >>>
> >>>
> >>
> >>
>
>
Re: Vaadin Integration and MetaData of mappings
Posted by Andrus Adamchik <an...@objectstyle.org>.
1. Serialization. There's not much to it really. Just make sure the context you are using is session-scoped. See for instance this class that provides a session-bound context (used by CayenneFilter) :
http://svn.apache.org/viewvc/cayenne/main/branches/STABLE-3.1/framework/cayenne-jdk1.5-unpublished/src/main/java/org/apache/cayenne/configuration/web/SessionContextRequestHandler.java?view=markup
2. Multi-tenancy... So if you go with DB-schema per tenant, it might look like this:
// do it once per tenant, and cache the returned runtime in the app scope
ServerRuntime createServerRuntime(final String tenantSchema) {
// "cayenne-xyz.xml" is a mapping common to all tenants, that will be further customized here
ServerRuntime runtime = new ServerRuntime("cayenne-xyz.xml", new Module() {
// in a custom module override the schema of all loaded DataMaps
public void configure(Binder binder) {
binder.bind(DataMapLoader.class).toInstance(new TenantMapLoader(tenantSchema));
}
});
return runtime;
}
class TenantMapLoader extends XMLDataMapLoader {
private String tenantSchema;
TenantMapLoader(String tenantSchema) {
this.tenantSchema = tenantSchema;
}
public DataMap load(Resource configurationResource) {
DataMap map = super.load(configurationResource);
map.setDefaultSchema(tenantSchema);
for(DbEntity e : map.getDbEntities()) {
e.setSchema(tenantSchema);
}
return map;
}
}
Andrus
On Aug 29, 2012, at 4:15 PM, Juan José Gil wrote:
> Thanks for the reply Andrus!
>
> Could you point me to docs/samples about ObjectContext Serialization &
> multi-tenant approaches you describe?
>
> About the"adding-metadata" part, I was thinking in adding constraints in a
> similar way to active-record in RoR or GORM in grails, but using code
> generation phases of cayenne.
>
> By now i'll use some kind of "typed" KVC delegating to cayenne the
> properties access and then providing some kind a "class metadata" which can
> be extended by subclasses... but i'll prefer the "code generation" form, so
> I can use IDEs capabilities.
>
> maybe I'll generate some "java code configuration" which then will be used
> to generate final classes... it sounds as a mess but it could give really
> nice possibilities! don't you think?
>
> if i get to somewhere with this approach I'll tell you :)
>
>>
>>
>>> the data objects will reside at the http session, and will be used
>> directly by the vaadin widgets, does this kind of cayenne data objects
>> "use" could arrive with attaching/detaching problems?
>>
>> Shouldn't be a problem. You can store Cayenne objects in a session. The
>> simplest way to avoid attach/detach issues is to have a session-scoped
>> ObjectContext. Then it is serialized/deserialized together with the objects
>> in case the session is saved to disk, or replicated across the cluster.
>>
>>> Also, is there a way to add metadata info in cayenne metamodel? I would
>> like to add constraints / validations to generated classes, so they can be
>> used to define searching criterias on indexed attributes (something like
>> active-records class filters, but only on indexed properties) and generate
>> model validations on properties so they can be used at UI fields directly,
>> facilitating the app development.
>>
>> You can add extra info using callbacks or lifecycle listeners. Any extra
>> properties can be defined either manually in generated subclasses, or even
>> stored in the base CayenneDataObject (with 'readProperty' / 'writeProperty'
>> methods, and custom property names).
>>
>>> Finally, I'm looking for a multitenant implementation to use, and I
>> believe that the solution pointed at
>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/could be also used with cayenne; is there any constraint I should look for?
>>
>> Cayenne is certainly friendly to various multi-tenancy approaches. In 3.1
>> API terms, you might assign a separate instance of ServerRuntime to each
>> tenant, and use that to create ObjectContexts for its users. You may start
>> all runtimes from the same basic configuration, and "namespace" them using
>> tenant-unique DB URL. Or you may use a single DataSource, and after a
>> runtime is loaded, scan through all its DbEntities and assign a tenant
>> "schema" to them. Feel free to ask about further details.
>>
>> Andrus
>>
>>
>> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
>>> Hello, I'm thinking to use cayenne in conjunction with vaadin (
>> http://vaadin.com).
>>>
>>> I'm trying to use some kind of tight integration between both frameworks
>> (defining cayenne generated classes which are vaadin data models
>> implementations).
>>> That way I could define forms directly on data objects, querying &
>> mutating its state directly from vaadin widgets.
>>> As vaadin is an stateful web framework, should I have to expect for some
>> kind of problem with data objects between requests? I mean, the data
>> objects will reside at the http session, and will be used directly by the
>> vaadin widgets, does this kind of cayenne data objects "use" could arrive
>> with attaching/detaching problems?
>>>
>>> Also, is there a way to add metadata info in cayenne metamodel? I would
>> like to add constraints / validations to generated classes, so they can be
>> used to define searching criterias on indexed attributes (something like
>> active-records class filters, but only on indexed properties) and generate
>> model validations on properties so they can be used at UI fields directly,
>> facilitating the app development.
>>>
>>> Finally, I'm looking for a multitenant implementation to use, and I
>> believe that the solution pointed at
>> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/could be also used with cayenne; is there any constraint I should look for?
>>>
>>> Best regards
>>> Juanjo
>>>
>>> ps: pardon my really poor English! :P
>>>
>>>
>>
>>
Re: Vaadin Integration and MetaData of mappings
Posted by Juan José Gil <ma...@gmail.com>.
Thanks for the reply Andrus!
Could you point me to docs/samples about ObjectContext Serialization &
multi-tenant approaches you describe?
About the"adding-metadata" part, I was thinking in adding constraints in a
similar way to active-record in RoR or GORM in grails, but using code
generation phases of cayenne.
By now i'll use some kind of "typed" KVC delegating to cayenne the
properties access and then providing some kind a "class metadata" which can
be extended by subclasses... but i'll prefer the "code generation" form, so
I can use IDEs capabilities.
maybe I'll generate some "java code configuration" which then will be used
to generate final classes... it sounds as a mess but it could give really
nice possibilities! don't you think?
if i get to somewhere with this approach I'll tell you :)
>
>
> > the data objects will reside at the http session, and will be used
> directly by the vaadin widgets, does this kind of cayenne data objects
> "use" could arrive with attaching/detaching problems?
>
> Shouldn't be a problem. You can store Cayenne objects in a session. The
> simplest way to avoid attach/detach issues is to have a session-scoped
> ObjectContext. Then it is serialized/deserialized together with the objects
> in case the session is saved to disk, or replicated across the cluster.
>
> > Also, is there a way to add metadata info in cayenne metamodel? I would
> like to add constraints / validations to generated classes, so they can be
> used to define searching criterias on indexed attributes (something like
> active-records class filters, but only on indexed properties) and generate
> model validations on properties so they can be used at UI fields directly,
> facilitating the app development.
>
> You can add extra info using callbacks or lifecycle listeners. Any extra
> properties can be defined either manually in generated subclasses, or even
> stored in the base CayenneDataObject (with 'readProperty' / 'writeProperty'
> methods, and custom property names).
>
> > Finally, I'm looking for a multitenant implementation to use, and I
> believe that the solution pointed at
> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/could be also used with cayenne; is there any constraint I should look for?
>
> Cayenne is certainly friendly to various multi-tenancy approaches. In 3.1
> API terms, you might assign a separate instance of ServerRuntime to each
> tenant, and use that to create ObjectContexts for its users. You may start
> all runtimes from the same basic configuration, and "namespace" them using
> tenant-unique DB URL. Or you may use a single DataSource, and after a
> runtime is loaded, scan through all its DbEntities and assign a tenant
> "schema" to them. Feel free to ask about further details.
>
> Andrus
>
>
> On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
> > Hello, I'm thinking to use cayenne in conjunction with vaadin (
> http://vaadin.com).
> >
> > I'm trying to use some kind of tight integration between both frameworks
> (defining cayenne generated classes which are vaadin data models
> implementations).
> > That way I could define forms directly on data objects, querying &
> mutating its state directly from vaadin widgets.
> > As vaadin is an stateful web framework, should I have to expect for some
> kind of problem with data objects between requests? I mean, the data
> objects will reside at the http session, and will be used directly by the
> vaadin widgets, does this kind of cayenne data objects "use" could arrive
> with attaching/detaching problems?
> >
> > Also, is there a way to add metadata info in cayenne metamodel? I would
> like to add constraints / validations to generated classes, so they can be
> used to define searching criterias on indexed attributes (something like
> active-records class filters, but only on indexed properties) and generate
> model validations on properties so they can be used at UI fields directly,
> facilitating the app development.
> >
> > Finally, I'm looking for a multitenant implementation to use, and I
> believe that the solution pointed at
> http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/could be also used with cayenne; is there any constraint I should look for?
> >
> > Best regards
> > Juanjo
> >
> > ps: pardon my really poor English! :P
> >
> >
>
>
Re: Vaadin Integration and MetaData of mappings
Posted by Andrus Adamchik <an...@objectstyle.org>.
Hi Juanjo,
> the data objects will reside at the http session, and will be used directly by the vaadin widgets, does this kind of cayenne data objects "use" could arrive with attaching/detaching problems?
Shouldn't be a problem. You can store Cayenne objects in a session. The simplest way to avoid attach/detach issues is to have a session-scoped ObjectContext. Then it is serialized/deserialized together with the objects in case the session is saved to disk, or replicated across the cluster.
> Also, is there a way to add metadata info in cayenne metamodel? I would like to add constraints / validations to generated classes, so they can be used to define searching criterias on indexed attributes (something like active-records class filters, but only on indexed properties) and generate model validations on properties so they can be used at UI fields directly, facilitating the app development.
You can add extra info using callbacks or lifecycle listeners. Any extra properties can be defined either manually in generated subclasses, or even stored in the base CayenneDataObject (with 'readProperty' / 'writeProperty' methods, and custom property names).
> Finally, I'm looking for a multitenant implementation to use, and I believe that the solution pointed at http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/ could be also used with cayenne; is there any constraint I should look for?
Cayenne is certainly friendly to various multi-tenancy approaches. In 3.1 API terms, you might assign a separate instance of ServerRuntime to each tenant, and use that to create ObjectContexts for its users. You may start all runtimes from the same basic configuration, and "namespace" them using tenant-unique DB URL. Or you may use a single DataSource, and after a runtime is loaded, scan through all its DbEntities and assign a tenant "schema" to them. Feel free to ask about further details.
Andrus
On Aug 26, 2012, at 5:15 PM, Juan J. Gil wrote:
> Hello, I'm thinking to use cayenne in conjunction with vaadin (http://vaadin.com).
>
> I'm trying to use some kind of tight integration between both frameworks (defining cayenne generated classes which are vaadin data models implementations).
> That way I could define forms directly on data objects, querying & mutating its state directly from vaadin widgets.
> As vaadin is an stateful web framework, should I have to expect for some kind of problem with data objects between requests? I mean, the data objects will reside at the http session, and will be used directly by the vaadin widgets, does this kind of cayenne data objects "use" could arrive with attaching/detaching problems?
>
> Also, is there a way to add metadata info in cayenne metamodel? I would like to add constraints / validations to generated classes, so they can be used to define searching criterias on indexed attributes (something like active-records class filters, but only on indexed properties) and generate model validations on properties so they can be used at UI fields directly, facilitating the app development.
>
> Finally, I'm looking for a multitenant implementation to use, and I believe that the solution pointed at http://blog.jerodsanto.net/2011/07/building-multi-tenant-rails-apps-with-postgresql-schemas/ could be also used with cayenne; is there any constraint I should look for?
>
> Best regards
> Juanjo
>
> ps: pardon my really poor English! :P
>
>