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Posted to users@wicket.apache.org by pieter claassen <pi...@claassen.co.uk> on 2009/02/12 14:57:49 UTC
Listview and Link sometimes fail to get objects from DB
Listviews with Links in them, sometimes fail to retrieve the object in the
onClick() method the first time around. When I reload the page, the code
works fine.
Here is a test. In the listview below, I load the page and in the listview
loop code, I correctly retrieve the item. Note that in the onClick() the
modelobject is null.
TEMPLATE NAME IN listview: first
TEMPLATE NAME IN onClick(): null
Reloading the page, and the problem goes away.
TEMPLATE NAME IN listview: first
TEMPLATE NAME IN onClick(): first
This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
when I restart my application.
Any ideas?
Example code:
ListView templateList = new ListView("listview", ModelConverter
.getModelList(templates, TemplateWebModel.class)) {
@Override
protected void populateItem(ListItem item) {
final TemplateWebModel templatewebmodel = (TemplateWebModel)
item
.getModelObject();
System.out.println("TEMPLATE NAME IN listview: "
+ templatewebmodel.getEntity().getName());
item.setModel(new CompoundPropertyModel(templatewebmodel));
...
item.add(new Link("edit") {
@Override
public void onClick() {
System.out.println("TEMPLATE NAME IN onClick(): "
+ templatewebmodel.getEntity().getName());
setResponsePage(new
TemplateEditPage(templatewebmodel));
}
});
...
Re: Listview and Link sometimes fail to get objects from DB
Posted by Martin Makundi <ma...@koodaripalvelut.com>.
What happens if you run a debugger and debug line-by-line? Put a
breakpoint somewhere where the null value appears from. It looks like
something else than a wicket bug.
**
Martin
2009/2/12 pieter claassen <pi...@gmail.com>:
> The value "first" is a field on a template, that is retrieved as one
> template from the list of all templates, from a db4o database using a DAO
> class.
>
> List<Template> templates = getTemplateFactory().getAll();
>
> So, this list is *always* retrieved correctly. Each of the templates are
> correctly backed by a database object and I can retrieve any field on any
> one of them.
> Each one of the template objects are wrapped in a thin wrapper where they
> are converted from a "heavy" object (Template) to a thin webmodel
> (TemplateWebModel)
>
> List templatewebmodels = ModelConverter.getModelList(templates,
> TemplateWebModel.class)
>
> In the listview block, I set the model for each list iteration:
>
> final TemplateWebModel templatewebmodel = (TemplateWebModel)
> item.getModelObject();
> item.setModel(new CompoundPropertyModel(templatewebmodel));
>
> and when I want to access the database object, I use:
>
> getModelObject().getEntity()
>
> This approach works both in the listview block of code, but not in any
> onClick() methods of Links that I include in the listview, just after I
> started my application. The second time around, things work fine.
>
> Is this possibly a wicket problem?
>
> Rgrds,
> Pieter
>
>
>
> On Thu, Feb 12, 2009 at 3:06 PM, Martin Makundi <
> martin.makundi@koodaripalvelut.com> wrote:
>
>> Where do you set the value "first"?
>>
>> **
>> Martin
>>
>> 2009/2/12 pieter claassen <pi...@claassen.co.uk>:
>> > Listviews with Links in them, sometimes fail to retrieve the object in
>> the
>> > onClick() method the first time around. When I reload the page, the code
>> > works fine.
>> >
>> > Here is a test. In the listview below, I load the page and in the
>> listview
>> > loop code, I correctly retrieve the item. Note that in the onClick() the
>> > modelobject is null.
>> >
>> > TEMPLATE NAME IN listview: first
>> > TEMPLATE NAME IN onClick(): null
>> >
>> > Reloading the page, and the problem goes away.
>> >
>> > TEMPLATE NAME IN listview: first
>> > TEMPLATE NAME IN onClick(): first
>> >
>> >
>> > This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
>> > when I restart my application.
>> >
>> > Any ideas?
>> >
>> > Example code:
>> >
>> > ListView templateList = new ListView("listview", ModelConverter
>> > .getModelList(templates, TemplateWebModel.class)) {
>> > @Override
>> > protected void populateItem(ListItem item) {
>> > final TemplateWebModel templatewebmodel =
>> (TemplateWebModel)
>> > item
>> > .getModelObject();
>> > System.out.println("TEMPLATE NAME IN listview: "
>> > + templatewebmodel.getEntity().getName());
>> >
>> > item.setModel(new
>> CompoundPropertyModel(templatewebmodel));
>> > ...
>> > item.add(new Link("edit") {
>> > @Override
>> > public void onClick() {
>> > System.out.println("TEMPLATE NAME IN onClick(): "
>> > + templatewebmodel.getEntity().getName());
>> > setResponsePage(new
>> > TemplateEditPage(templatewebmodel));
>> > }
>> > });
>> > ...
>> >
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>> For additional commands, e-mail: users-help@wicket.apache.org
>>
>>
>
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Re: Listview and Link sometimes fail to get objects from DB
Posted by pieter claassen <pi...@gmail.com>.
The value "first" is a field on a template, that is retrieved as one
template from the list of all templates, from a db4o database using a DAO
class.
List<Template> templates = getTemplateFactory().getAll();
So, this list is *always* retrieved correctly. Each of the templates are
correctly backed by a database object and I can retrieve any field on any
one of them.
Each one of the template objects are wrapped in a thin wrapper where they
are converted from a "heavy" object (Template) to a thin webmodel
(TemplateWebModel)
List templatewebmodels = ModelConverter.getModelList(templates,
TemplateWebModel.class)
In the listview block, I set the model for each list iteration:
final TemplateWebModel templatewebmodel = (TemplateWebModel)
item.getModelObject();
item.setModel(new CompoundPropertyModel(templatewebmodel));
and when I want to access the database object, I use:
getModelObject().getEntity()
This approach works both in the listview block of code, but not in any
onClick() methods of Links that I include in the listview, just after I
started my application. The second time around, things work fine.
Is this possibly a wicket problem?
Rgrds,
Pieter
On Thu, Feb 12, 2009 at 3:06 PM, Martin Makundi <
martin.makundi@koodaripalvelut.com> wrote:
> Where do you set the value "first"?
>
> **
> Martin
>
> 2009/2/12 pieter claassen <pi...@claassen.co.uk>:
> > Listviews with Links in them, sometimes fail to retrieve the object in
> the
> > onClick() method the first time around. When I reload the page, the code
> > works fine.
> >
> > Here is a test. In the listview below, I load the page and in the
> listview
> > loop code, I correctly retrieve the item. Note that in the onClick() the
> > modelobject is null.
> >
> > TEMPLATE NAME IN listview: first
> > TEMPLATE NAME IN onClick(): null
> >
> > Reloading the page, and the problem goes away.
> >
> > TEMPLATE NAME IN listview: first
> > TEMPLATE NAME IN onClick(): first
> >
> >
> > This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
> > when I restart my application.
> >
> > Any ideas?
> >
> > Example code:
> >
> > ListView templateList = new ListView("listview", ModelConverter
> > .getModelList(templates, TemplateWebModel.class)) {
> > @Override
> > protected void populateItem(ListItem item) {
> > final TemplateWebModel templatewebmodel =
> (TemplateWebModel)
> > item
> > .getModelObject();
> > System.out.println("TEMPLATE NAME IN listview: "
> > + templatewebmodel.getEntity().getName());
> >
> > item.setModel(new
> CompoundPropertyModel(templatewebmodel));
> > ...
> > item.add(new Link("edit") {
> > @Override
> > public void onClick() {
> > System.out.println("TEMPLATE NAME IN onClick(): "
> > + templatewebmodel.getEntity().getName());
> > setResponsePage(new
> > TemplateEditPage(templatewebmodel));
> > }
> > });
> > ...
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
Re: Listview and Link sometimes fail to get objects from DB
Posted by Martin Makundi <ma...@koodaripalvelut.com>.
Where do you set the value "first"?
**
Martin
2009/2/12 pieter claassen <pi...@claassen.co.uk>:
> Listviews with Links in them, sometimes fail to retrieve the object in the
> onClick() method the first time around. When I reload the page, the code
> works fine.
>
> Here is a test. In the listview below, I load the page and in the listview
> loop code, I correctly retrieve the item. Note that in the onClick() the
> modelobject is null.
>
> TEMPLATE NAME IN listview: first
> TEMPLATE NAME IN onClick(): null
>
> Reloading the page, and the problem goes away.
>
> TEMPLATE NAME IN listview: first
> TEMPLATE NAME IN onClick(): first
>
>
> This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
> when I restart my application.
>
> Any ideas?
>
> Example code:
>
> ListView templateList = new ListView("listview", ModelConverter
> .getModelList(templates, TemplateWebModel.class)) {
> @Override
> protected void populateItem(ListItem item) {
> final TemplateWebModel templatewebmodel = (TemplateWebModel)
> item
> .getModelObject();
> System.out.println("TEMPLATE NAME IN listview: "
> + templatewebmodel.getEntity().getName());
>
> item.setModel(new CompoundPropertyModel(templatewebmodel));
> ...
> item.add(new Link("edit") {
> @Override
> public void onClick() {
> System.out.println("TEMPLATE NAME IN onClick(): "
> + templatewebmodel.getEntity().getName());
> setResponsePage(new
> TemplateEditPage(templatewebmodel));
> }
> });
> ...
>
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Re: Listview and Link sometimes fail to get objects from DB
Posted by Igor Vaynberg <ig...@gmail.com>.
so getmodelobject() returns another imodel?
you should really look into a dataview instead of a listview - it will
make things easier to understand.
a listview does not expect a list of imodels, it expects a list of
objects. each item then wraps each object in a imodel that can
retrieve it if needed in listview#getlistitemmodel(). the list should
usually be retrieved via a loadabledetachablemodel.
anyways, dataviews make all this much simpler.
-igor
On Thu, Feb 12, 2009 at 7:56 AM, pieter claassen
<pi...@gmail.com> wrote:
> Hi Igor,
>
> Am I screwing up because I thought I did convert all my code to use only
> webmodels? Maybe I still fail to understand the database-wicket integration
> part.
>
> First I get all objects from the database:
>
> List<Template> templates = getTemplateFactory().getAll();
>
> But they are fat and need to be wrapped by models:
>
> ListView templateList = new ListView("listview",
> ModelConverter.getModelList(templates, TemplateWebModel.class)) {
>
> ModelConverter.getModelList(templates, TemplateWebModel.class)) is a helper
> method that converts all my objects into models.
>
> final TemplateWebModel templatewebmodel = (TemplateWebModel)
> item
> .getModelObject();
> item.setModel(new CompoundPropertyModel(templatewebmodel));
>
> This is more verbose, but isn't this the same as what you just recommended?
> TemplateWebModel is an implementation of IModel.
>
> getModelObject() returns an IModel object because I convert my database
> objects to webmodels before I even render the list
>
> Debugging this problem with a debugger seems unproductive because it seems
> to never be there when I debug.
>
> P
>
>
> On Thu, Feb 12, 2009 at 4:15 PM, Igor Vaynberg <ig...@gmail.com>wrote:
>
>> this code is very bad, you should use models so that you do not end up
>> serializing your entities...
>>
>> item.setModel(new CompoundPropertyModel( item.getmodel() ));
>> ...
>> item.add(new Link("edit" , item.getmodel() ) {
>> @Override
>> public void onClick() {
>> System.out.println("TEMPLATE NAME IN onClick(): "
>> + getmodelobject()
>> .getEntity().getName());
>> setResponsePage(new
>> TemplateEditPage( getmodel() ));
>> }
>> });
>>
>> -igor
>>
>> On Thu, Feb 12, 2009 at 5:57 AM, pieter claassen <pi...@claassen.co.uk>
>> wrote:
>> > Listviews with Links in them, sometimes fail to retrieve the object in
>> the
>> > onClick() method the first time around. When I reload the page, the code
>> > works fine.
>> >
>> > Here is a test. In the listview below, I load the page and in the
>> listview
>> > loop code, I correctly retrieve the item. Note that in the onClick() the
>> > modelobject is null.
>> >
>> > TEMPLATE NAME IN listview: first
>> > TEMPLATE NAME IN onClick(): null
>> >
>> > Reloading the page, and the problem goes away.
>> >
>> > TEMPLATE NAME IN listview: first
>> > TEMPLATE NAME IN onClick(): first
>> >
>> >
>> > This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
>> > when I restart my application.
>> >
>> > Any ideas?
>> >
>> > Example code:
>> >
>> > ListView templateList = new ListView("listview", ModelConverter
>> > .getModelList(templates, TemplateWebModel.class)) {
>> > @Override
>> > protected void populateItem(ListItem item) {
>> > final TemplateWebModel templatewebmodel =
>> (TemplateWebModel)
>> > item
>> > .getModelObject();
>> > System.out.println("TEMPLATE NAME IN listview: "
>> > + templatewebmodel.getEntity().getName());
>> >
>> > item.setModel(new
>> CompoundPropertyModel(templatewebmodel));
>> > ...
>> > item.add(new Link("edit") {
>> > @Override
>> > public void onClick() {
>> > System.out.println("TEMPLATE NAME IN onClick(): "
>> > + templatewebmodel.getEntity().getName());
>> > setResponsePage(new
>> > TemplateEditPage(templatewebmodel));
>> > }
>> > });
>> > ...
>> >
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>> For additional commands, e-mail: users-help@wicket.apache.org
>>
>>
>
---------------------------------------------------------------------
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Re: Listview and Link sometimes fail to get objects from DB
Posted by pieter claassen <pi...@gmail.com>.
Hi Igor,
Am I screwing up because I thought I did convert all my code to use only
webmodels? Maybe I still fail to understand the database-wicket integration
part.
First I get all objects from the database:
List<Template> templates = getTemplateFactory().getAll();
But they are fat and need to be wrapped by models:
ListView templateList = new ListView("listview",
ModelConverter.getModelList(templates, TemplateWebModel.class)) {
ModelConverter.getModelList(templates, TemplateWebModel.class)) is a helper
method that converts all my objects into models.
final TemplateWebModel templatewebmodel = (TemplateWebModel)
item
.getModelObject();
item.setModel(new CompoundPropertyModel(templatewebmodel));
This is more verbose, but isn't this the same as what you just recommended?
TemplateWebModel is an implementation of IModel.
getModelObject() returns an IModel object because I convert my database
objects to webmodels before I even render the list
Debugging this problem with a debugger seems unproductive because it seems
to never be there when I debug.
P
On Thu, Feb 12, 2009 at 4:15 PM, Igor Vaynberg <ig...@gmail.com>wrote:
> this code is very bad, you should use models so that you do not end up
> serializing your entities...
>
> item.setModel(new CompoundPropertyModel( item.getmodel() ));
> ...
> item.add(new Link("edit" , item.getmodel() ) {
> @Override
> public void onClick() {
> System.out.println("TEMPLATE NAME IN onClick(): "
> + getmodelobject()
> .getEntity().getName());
> setResponsePage(new
> TemplateEditPage( getmodel() ));
> }
> });
>
> -igor
>
> On Thu, Feb 12, 2009 at 5:57 AM, pieter claassen <pi...@claassen.co.uk>
> wrote:
> > Listviews with Links in them, sometimes fail to retrieve the object in
> the
> > onClick() method the first time around. When I reload the page, the code
> > works fine.
> >
> > Here is a test. In the listview below, I load the page and in the
> listview
> > loop code, I correctly retrieve the item. Note that in the onClick() the
> > modelobject is null.
> >
> > TEMPLATE NAME IN listview: first
> > TEMPLATE NAME IN onClick(): null
> >
> > Reloading the page, and the problem goes away.
> >
> > TEMPLATE NAME IN listview: first
> > TEMPLATE NAME IN onClick(): first
> >
> >
> > This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
> > when I restart my application.
> >
> > Any ideas?
> >
> > Example code:
> >
> > ListView templateList = new ListView("listview", ModelConverter
> > .getModelList(templates, TemplateWebModel.class)) {
> > @Override
> > protected void populateItem(ListItem item) {
> > final TemplateWebModel templatewebmodel =
> (TemplateWebModel)
> > item
> > .getModelObject();
> > System.out.println("TEMPLATE NAME IN listview: "
> > + templatewebmodel.getEntity().getName());
> >
> > item.setModel(new
> CompoundPropertyModel(templatewebmodel));
> > ...
> > item.add(new Link("edit") {
> > @Override
> > public void onClick() {
> > System.out.println("TEMPLATE NAME IN onClick(): "
> > + templatewebmodel.getEntity().getName());
> > setResponsePage(new
> > TemplateEditPage(templatewebmodel));
> > }
> > });
> > ...
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>
Re: Listview and Link sometimes fail to get objects from DB
Posted by Igor Vaynberg <ig...@gmail.com>.
this code is very bad, you should use models so that you do not end up
serializing your entities...
item.setModel(new CompoundPropertyModel( item.getmodel() ));
...
item.add(new Link("edit" , item.getmodel() ) {
@Override
public void onClick() {
System.out.println("TEMPLATE NAME IN onClick(): "
+ getmodelobject() .getEntity().getName());
setResponsePage(new
TemplateEditPage( getmodel() ));
}
});
-igor
On Thu, Feb 12, 2009 at 5:57 AM, pieter claassen <pi...@claassen.co.uk> wrote:
> Listviews with Links in them, sometimes fail to retrieve the object in the
> onClick() method the first time around. When I reload the page, the code
> works fine.
>
> Here is a test. In the listview below, I load the page and in the listview
> loop code, I correctly retrieve the item. Note that in the onClick() the
> modelobject is null.
>
> TEMPLATE NAME IN listview: first
> TEMPLATE NAME IN onClick(): null
>
> Reloading the page, and the problem goes away.
>
> TEMPLATE NAME IN listview: first
> TEMPLATE NAME IN onClick(): first
>
>
> This is using wicket 1.3.5. and db4o 7.8. This problem is normally there
> when I restart my application.
>
> Any ideas?
>
> Example code:
>
> ListView templateList = new ListView("listview", ModelConverter
> .getModelList(templates, TemplateWebModel.class)) {
> @Override
> protected void populateItem(ListItem item) {
> final TemplateWebModel templatewebmodel = (TemplateWebModel)
> item
> .getModelObject();
> System.out.println("TEMPLATE NAME IN listview: "
> + templatewebmodel.getEntity().getName());
>
> item.setModel(new CompoundPropertyModel(templatewebmodel));
> ...
> item.add(new Link("edit") {
> @Override
> public void onClick() {
> System.out.println("TEMPLATE NAME IN onClick(): "
> + templatewebmodel.getEntity().getName());
> setResponsePage(new
> TemplateEditPage(templatewebmodel));
> }
> });
> ...
>
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