Re: Refreshing a list while using ListDataProvider
Rereading the link
http://cwiki.apache.org/WICKET/reading-from-a-database.html
http://cwiki.apache.org/WICKET/reading-from-a-database.html
clearly says that the objects are created only once, this includes the List
results i guess. But the line --
results = getResultsFromCriteria(criteria);
is kinda misleading.. In this case the results should never be a new
ArrayList object for DataView to work. (If using ListView, the setList must
be used).
For eg, when using Spring's JdbcTemplate.queryForList() it always returns a
new list object. To make DataView work, this is probably what should happen:
List tempResult = getResultsFromCriteria(criteria);
results.clear();
results.addAll(tempResult);
Pls correct me if im wrong...
On Tue, May 26, 2009 at 4:48 PM, Vasu Srinivasan vasy...@gmail.com wrote:
Ok I think I am understanding it a little better now.
For now Im still extending myDataProvider from ListDataProvider, but no
longer using a new ArrayList() for every search. Im clearing it out and
adding new data, which is okay.
One question though -- What is the responsibility scope of the
ListDataProvider / IDataProvider?
Am I correct in assuming the following --
1) only operate on the given List/Data (already manipulated)
2) *should not* contain a Dao, and refresh its own list/data.
Because if (2), then I am seeing an issue -- where do I call the
dao.query() ? In the constructor or in the iterator() ? If I do in the
constructor, its not refreshed for further queries. If I do in the
iterator(), then the size() is queried before the DataView calls the
iterator(), so it always returns 0 records for the first time. And also
calling dao.query() in the iterator() will make it query the whole list for
every pagination, which is probably not a good idea.
I liked the idea of dataprovider encapsulating dao, but not clear where
would I refresh it.
Thanks !
Vasya
On Tue, May 26, 2009 at 3:25 PM, Igor Vaynberg igor.vaynb...@gmail.comwrote:
i meant implement IDataProvider directly if ListDataProvider doesnt
work for you. most of the time you modify an existing instance of
List, not create a new one, so ListDataProvider is useful there.
-igor
On Tue, May 26, 2009 at 1:15 PM, Vasu Srinivasan vasy...@gmail.com
wrote:
Thanks for the reply ...
I tried doing this :
class MyDataProvider extends ListDataProvider {
DataDao dataDao;
Criteria criteria;
public MyDataProvider(List list, Criteria criteria) {
super(list);
...
}
//providing my own iterator which goes to the dataDao and gets the data
//But now I cannot set the list, because private... So I have to use my
own list member...If I do that, then what is the point of calling the
constructor with List?
}
Looks like ListDataProvider is not useful for reusable Lists. Not sure
why
this should be so ? If I am able to set a new List into the provider, I
would not be breaking anything because the data is anyway retrieved only
via
an Iterator.
The problem is even if I create a new ListDataProvider for every new
list, I
am not able to set that again in my data view. DataView does not have
any
thing similar to setList (a la ListView.setList). I dont think I should
be
creating a new DataView for every search, because all i'm doing is only
changing contents of the underlying list.
Am I missing something ?
On Tue, May 26, 2009 at 12:29 PM, Igor Vaynberg
igor.vaynb...@gmail.comwrote:
you can build your own analog of listdataprovider that pulls the list
directly from whatever property contains the latest.
-igor
On Tue, May 26, 2009 at 9:38 AM, Vasu Srinivasan vasy...@gmail.com
wrote:
Hello:
I have a simple search form , where some criteria refreshes the table
based
on the db. I got it working with ListView, but im trying to use
ListDataProvider, I feel missing something:
class MyForm {
List myList;
MyDataView myDataView;
MyDataProvider myDataProvider;
public MyForm() {
@Override public void onSubmit() {
myList = refreshData(criteria);
//Question: How do I set this list into the myDataView or
myDataProvider ? I thought myDataView or the provider will auto pick
it
up,
because its a member variable and is a RefreshingView
}
//First time
myList = refreshData(defaultCriteria);
myDataView = new MyDataView(myDataView , new
MyDataProvider(myList));
add(myListView);
}
}
class MyDataView extends DataView {
public MyDataView(String id, IDataProvider provider) { super(id,
provider); }
@Override public void populateItem(Item item) { }
}
class MyDataProvider extends ListDataProvider {
public MyDataProvider(List list) {
super(list);
}
}
I looked at the example that uses ListView
http://cwiki.apache.org/WICKET/reading-from-a-database.html
Re: Refreshing a list while using ListDataProvider
Vasu Srinivasan schrieb: Hello: I have a simple search form , where some criteria refreshes the table based on the db. I got it working with ListView, but im trying to use ListDataProvider, I feel missing something: the trick that worked for me: just re-use the existing list instance. final List l = ... new ListDataProvider(l); ..then in an ajax button l.clear(); l.add(stuff)... so just use the instance , the ListDataProvider will pick up the changes. - To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org For additional commands, e-mail: users-h...@wicket.apache.org
Refreshing a list while using ListDataProvider
Hello:
I have a simple search form , where some criteria refreshes the table based
on the db. I got it working with ListView, but im trying to use
ListDataProvider, I feel missing something:
class MyForm {
List myList;
MyDataView myDataView;
MyDataProvider myDataProvider;
public MyForm() {
@Override public void onSubmit() {
myList = refreshData(criteria);
//Question: How do I set this list into the myDataView or
myDataProvider ? I thought myDataView or the provider will auto pick it up,
because its a member variable and is a RefreshingView
}
//First time
myList = refreshData(defaultCriteria);
myDataView = new MyDataView(myDataView , new MyDataProvider(myList));
add(myListView);
}
}
class MyDataView extends DataView {
public MyDataView(String id, IDataProvider provider) { super(id,
provider); }
@Override public void populateItem(Item item) { }
}
class MyDataProvider extends ListDataProvider {
public MyDataProvider(List list) {
super(list);
}
}
I looked at the example that uses ListView
http://cwiki.apache.org/WICKET/reading-from-a-database.html
http://cwiki.apache.org/WICKET/reading-from-a-database.html
With ListView it works fine if I do this in the method onSubmit()
myList = refreshData(criteria);
myListView.setList(myList);
But with DataView, I do not have a set method to reset the new list obtained
based on the criteria. The db returns correct data, but the page displays
the old data (no change). Neither do I see a method to set the new list in
the ListDataProvider.
I even tried adding a new view inside the onSubmit, but that doesnt work
either:
myDataView = new MyDataView(myDataView, new MyDataProvider(newList));
--
Thanks!
Vasu Srinivasan
Re: Refreshing a list while using ListDataProvider
you can build your own analog of listdataprovider that pulls the list
directly from whatever property contains the latest.
-igor
On Tue, May 26, 2009 at 9:38 AM, Vasu Srinivasan vasy...@gmail.com wrote:
Hello:
I have a simple search form , where some criteria refreshes the table based
on the db. I got it working with ListView, but im trying to use
ListDataProvider, I feel missing something:
class MyForm {
List myList;
MyDataView myDataView;
MyDataProvider myDataProvider;
public MyForm() {
�...@override public void onSubmit() {
myList = refreshData(criteria);
//Question: How do I set this list into the myDataView or
myDataProvider ? I thought myDataView or the provider will auto pick it up,
because its a member variable and is a RefreshingView
}
//First time
myList = refreshData(defaultCriteria);
myDataView = new MyDataView(myDataView , new MyDataProvider(myList));
add(myListView);
}
}
class MyDataView extends DataView {
public MyDataView(String id, IDataProvider provider) { super(id,
provider); }
@Override public void populateItem(Item item) { }
}
class MyDataProvider extends ListDataProvider {
public MyDataProvider(List list) {
super(list);
}
}
I looked at the example that uses ListView
http://cwiki.apache.org/WICKET/reading-from-a-database.html
http://cwiki.apache.org/WICKET/reading-from-a-database.html
With ListView it works fine if I do this in the method onSubmit()
myList = refreshData(criteria);
myListView.setList(myList);
But with DataView, I do not have a set method to reset the new list obtained
based on the criteria. The db returns correct data, but the page displays
the old data (no change). Neither do I see a method to set the new list in
the ListDataProvider.
I even tried adding a new view inside the onSubmit, but that doesnt work
either:
myDataView = new MyDataView(myDataView, new MyDataProvider(newList));
--
Thanks!
Vasu Srinivasan
-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
Re: Refreshing a list while using ListDataProvider
Thanks for the reply ...
I tried doing this :
class MyDataProvider extends ListDataProvider {
DataDao dataDao;
Criteria criteria;
public MyDataProvider(List list, Criteria criteria) {
super(list);
...
}
//providing my own iterator which goes to the dataDao and gets the data
//But now I cannot set the list, because private... So I have to use my
own list member...If I do that, then what is the point of calling the
constructor with List?
}
Looks like ListDataProvider is not useful for reusable Lists. Not sure why
this should be so ? If I am able to set a new List into the provider, I
would not be breaking anything because the data is anyway retrieved only via
an Iterator.
The problem is even if I create a new ListDataProvider for every new list, I
am not able to set that again in my data view. DataView does not have any
thing similar to setList (a la ListView.setList). I dont think I should be
creating a new DataView for every search, because all i'm doing is only
changing contents of the underlying list.
Am I missing something ?
On Tue, May 26, 2009 at 12:29 PM, Igor Vaynberg igor.vaynb...@gmail.comwrote:
you can build your own analog of listdataprovider that pulls the list
directly from whatever property contains the latest.
-igor
On Tue, May 26, 2009 at 9:38 AM, Vasu Srinivasan vasy...@gmail.com
wrote:
Hello:
I have a simple search form , where some criteria refreshes the table
based
on the db. I got it working with ListView, but im trying to use
ListDataProvider, I feel missing something:
class MyForm {
List myList;
MyDataView myDataView;
MyDataProvider myDataProvider;
public MyForm() {
@Override public void onSubmit() {
myList = refreshData(criteria);
//Question: How do I set this list into the myDataView or
myDataProvider ? I thought myDataView or the provider will auto pick it
up,
because its a member variable and is a RefreshingView
}
//First time
myList = refreshData(defaultCriteria);
myDataView = new MyDataView(myDataView , new
MyDataProvider(myList));
add(myListView);
}
}
class MyDataView extends DataView {
public MyDataView(String id, IDataProvider provider) { super(id,
provider); }
@Override public void populateItem(Item item) { }
}
class MyDataProvider extends ListDataProvider {
public MyDataProvider(List list) {
super(list);
}
}
I looked at the example that uses ListView
http://cwiki.apache.org/WICKET/reading-from-a-database.html
http://cwiki.apache.org/WICKET/reading-from-a-database.html
With ListView it works fine if I do this in the method onSubmit()
myList = refreshData(criteria);
myListView.setList(myList);
But with DataView, I do not have a set method to reset the new list
obtained
based on the criteria. The db returns correct data, but the page displays
the old data (no change). Neither do I see a method to set the new list
in
the ListDataProvider.
I even tried adding a new view inside the onSubmit, but that doesnt work
either:
myDataView = new MyDataView(myDataView, new MyDataProvider(newList));
--
Thanks!
Vasu Srinivasan
-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
--
Regards,
Vasu Srinivasan
Re: Refreshing a list while using ListDataProvider
i meant implement IDataProvider directly if ListDataProvider doesnt
work for you. most of the time you modify an existing instance of
List, not create a new one, so ListDataProvider is useful there.
-igor
On Tue, May 26, 2009 at 1:15 PM, Vasu Srinivasan vasy...@gmail.com wrote:
Thanks for the reply ...
I tried doing this :
class MyDataProvider extends ListDataProvider {
DataDao dataDao;
Criteria criteria;
public MyDataProvider(List list, Criteria criteria) {
super(list);
...
}
//providing my own iterator which goes to the dataDao and gets the data
//But now I cannot set the list, because private... So I have to use my
own list member...If I do that, then what is the point of calling the
constructor with List?
}
Looks like ListDataProvider is not useful for reusable Lists. Not sure why
this should be so ? If I am able to set a new List into the provider, I
would not be breaking anything because the data is anyway retrieved only via
an Iterator.
The problem is even if I create a new ListDataProvider for every new list, I
am not able to set that again in my data view. DataView does not have any
thing similar to setList (a la ListView.setList). I dont think I should be
creating a new DataView for every search, because all i'm doing is only
changing contents of the underlying list.
Am I missing something ?
On Tue, May 26, 2009 at 12:29 PM, Igor Vaynberg
igor.vaynb...@gmail.comwrote:
you can build your own analog of listdataprovider that pulls the list
directly from whatever property contains the latest.
-igor
On Tue, May 26, 2009 at 9:38 AM, Vasu Srinivasan vasy...@gmail.com
wrote:
Hello:
I have a simple search form , where some criteria refreshes the table
based
on the db. I got it working with ListView, but im trying to use
ListDataProvider, I feel missing something:
class MyForm {
List myList;
MyDataView myDataView;
MyDataProvider myDataProvider;
public MyForm() {
�...@override public void onSubmit() {
myList = refreshData(criteria);
//Question: How do I set this list into the myDataView or
myDataProvider ? I thought myDataView or the provider will auto pick it
up,
because its a member variable and is a RefreshingView
}
//First time
myList = refreshData(defaultCriteria);
myDataView = new MyDataView(myDataView , new
MyDataProvider(myList));
add(myListView);
}
}
class MyDataView extends DataView {
public MyDataView(String id, IDataProvider provider) { super(id,
provider); }
@Override public void populateItem(Item item) { }
}
class MyDataProvider extends ListDataProvider {
public MyDataProvider(List list) {
super(list);
}
}
I looked at the example that uses ListView
http://cwiki.apache.org/WICKET/reading-from-a-database.html
http://cwiki.apache.org/WICKET/reading-from-a-database.html
With ListView it works fine if I do this in the method onSubmit()
myList = refreshData(criteria);
myListView.setList(myList);
But with DataView, I do not have a set method to reset the new list
obtained
based on the criteria. The db returns correct data, but the page displays
the old data (no change). Neither do I see a method to set the new list
in
the ListDataProvider.
I even tried adding a new view inside the onSubmit, but that doesnt work
either:
myDataView = new MyDataView(myDataView, new MyDataProvider(newList));
--
Thanks!
Vasu Srinivasan
-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
--
Regards,
Vasu Srinivasan
-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
Re: Refreshing a list while using ListDataProvider
Ok I think I am understanding it a little better now.
For now Im still extending myDataProvider from ListDataProvider, but no
longer using a new ArrayList() for every search. Im clearing it out and
adding new data, which is okay.
One question though -- What is the responsibility scope of the
ListDataProvider / IDataProvider?
Am I correct in assuming the following --
1) only operate on the given List/Data (already manipulated)
2) *should not* contain a Dao, and refresh its own list/data.
Because if (2), then I am seeing an issue -- where do I call the dao.query()
? In the constructor or in the iterator() ? If I do in the constructor, its
not refreshed for further queries. If I do in the iterator(), then the
size() is queried before the DataView calls the iterator(), so it always
returns 0 records for the first time. And also calling dao.query() in the
iterator() will make it query the whole list for every pagination, which is
probably not a good idea.
I liked the idea of dataprovider encapsulating dao, but not clear where
would I refresh it.
Thanks !
Vasya
On Tue, May 26, 2009 at 3:25 PM, Igor Vaynberg igor.vaynb...@gmail.comwrote:
i meant implement IDataProvider directly if ListDataProvider doesnt
work for you. most of the time you modify an existing instance of
List, not create a new one, so ListDataProvider is useful there.
-igor
On Tue, May 26, 2009 at 1:15 PM, Vasu Srinivasan vasy...@gmail.com
wrote:
Thanks for the reply ...
I tried doing this :
class MyDataProvider extends ListDataProvider {
DataDao dataDao;
Criteria criteria;
public MyDataProvider(List list, Criteria criteria) {
super(list);
...
}
//providing my own iterator which goes to the dataDao and gets the data
//But now I cannot set the list, because private... So I have to use my
own list member...If I do that, then what is the point of calling the
constructor with List?
}
Looks like ListDataProvider is not useful for reusable Lists. Not sure
why
this should be so ? If I am able to set a new List into the provider, I
would not be breaking anything because the data is anyway retrieved only
via
an Iterator.
The problem is even if I create a new ListDataProvider for every new
list, I
am not able to set that again in my data view. DataView does not have any
thing similar to setList (a la ListView.setList). I dont think I should
be
creating a new DataView for every search, because all i'm doing is only
changing contents of the underlying list.
Am I missing something ?
On Tue, May 26, 2009 at 12:29 PM, Igor Vaynberg igor.vaynb...@gmail.com
wrote:
you can build your own analog of listdataprovider that pulls the list
directly from whatever property contains the latest.
-igor
On Tue, May 26, 2009 at 9:38 AM, Vasu Srinivasan vasy...@gmail.com
wrote:
Hello:
I have a simple search form , where some criteria refreshes the table
based
on the db. I got it working with ListView, but im trying to use
ListDataProvider, I feel missing something:
class MyForm {
List myList;
MyDataView myDataView;
MyDataProvider myDataProvider;
public MyForm() {
@Override public void onSubmit() {
myList = refreshData(criteria);
//Question: How do I set this list into the myDataView or
myDataProvider ? I thought myDataView or the provider will auto pick
it
up,
because its a member variable and is a RefreshingView
}
//First time
myList = refreshData(defaultCriteria);
myDataView = new MyDataView(myDataView , new
MyDataProvider(myList));
add(myListView);
}
}
class MyDataView extends DataView {
public MyDataView(String id, IDataProvider provider) { super(id,
provider); }
@Override public void populateItem(Item item) { }
}
class MyDataProvider extends ListDataProvider {
public MyDataProvider(List list) {
super(list);
}
}
I looked at the example that uses ListView
http://cwiki.apache.org/WICKET/reading-from-a-database.html
http://cwiki.apache.org/WICKET/reading-from-a-database.html
With ListView it works fine if I do this in the method onSubmit()
myList = refreshData(criteria);
myListView.setList(myList);
But with DataView, I do not have a set method to reset the new list
obtained
based on the criteria. The db returns correct data, but the page
displays
the old data (no change). Neither do I see a method to set the new
list
in
the ListDataProvider.
I even tried adding a new view inside the onSubmit, but that doesnt
work
either:
myDataView = new MyDataView(myDataView, new
MyDataProvider(newList));
--
Thanks!
Vasu Srinivasan
-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail:
