You are viewing a plain text version of this content. The canonical link for it is here.
Posted to users@tapestry.apache.org by Michael Engelhart <me...@mac.com> on 2004/12/01 13:41:59 UTC
Dynamic PropertySelection requires persistence?
Hi -
I have a subclass of PropertySelection that I back with a database
supplied java.util.List of items depending on what the user enters into
a search form. I'm getting a NullPointerException when I select an
item from the PropertySelection and click submit. I put some
debugging code in and it seems the List that my model is backed by is
set to null somewhere in the prøcess. Do I have to make the model a
persistent page property for this to work? In other words does
Tapestry discard my Model as soon as the page is rendered?
Thanks for any help.
Michael
---------------------------------------------------------------------
To unsubscribe, e-mail: tapestry-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tapestry-user-help@jakarta.apache.org
Re: Dynamic PropertySelection requires persistence?
Posted by Michael Engelhart <me...@mac.com>.
Thanks Erik -
In my model I have a setPropertyList() method for the model's List
which I've been updating during the validation section of my Page code.
Being new to the concept of rewinding/rendering, what sections of my
code do I look at to make sure that it's being created/updated for
rewind/render? I do the validation inside my page's listener.submit
method so I thought that modifying the backing list by calling
MyPropertySelection.setPropertyList(List) would update during the
render. I also have tried creating a new PropertySelection object by
passing in the List to the constructor but that also failed with a
NullPointerException being that the List was still null. Do I need to
use a Tapestry.fireChangedObserver() call to update something?
Thanks again for your help.
Mike
On Dec 1, 2004, at 8:18 AM, Erik Hatcher wrote:
> The model doesn't have to be persistent, but the same model needs to
> be created both during render and rewind. Since you're backing it
> with a database, you may want to have some caching going on
> (depending on how frequently the data changes).
>
> Erik
>
> On Dec 1, 2004, at 7:41 AM, Michael Engelhart wrote:
>
>> Hi -
>>
>> I have a subclass of PropertySelection that I back with a database
>> supplied java.util.List of items depending on what the user enters
>> into a search form. I'm getting a NullPointerException when I
>> select an item from the PropertySelection and click submit. I put
>> some debugging code in and it seems the List that my model is backed
>> by is set to null somewhere in the prøcess. Do I have to make the
>> model a persistent page property for this to work? In other words
>> does Tapestry discard my Model as soon as the page is rendered?
>>
>> Thanks for any help.
>> Michael
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: tapestry-user-unsubscribe@jakarta.apache.org
>> For additional commands, e-mail: tapestry-user-help@jakarta.apache.org
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tapestry-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tapestry-user-help@jakarta.apache.org
>
---------------------------------------------------------------------
To unsubscribe, e-mail: tapestry-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tapestry-user-help@jakarta.apache.org
Re: Dynamic PropertySelection requires persistence?
Posted by Erik Hatcher <er...@ehatchersolutions.com>.
The model doesn't have to be persistent, but the same model needs to be
created both during render and rewind. Since you're backing it with a
database, you may want to have some caching going on (depending on how
frequently the data changes).
Erik
On Dec 1, 2004, at 7:41 AM, Michael Engelhart wrote:
> Hi -
>
> I have a subclass of PropertySelection that I back with a database
> supplied java.util.List of items depending on what the user enters
> into a search form. I'm getting a NullPointerException when I select
> an item from the PropertySelection and click submit. I put some
> debugging code in and it seems the List that my model is backed by is
> set to null somewhere in the prøcess. Do I have to make the model a
> persistent page property for this to work? In other words does
> Tapestry discard my Model as soon as the page is rendered?
>
> Thanks for any help.
> Michael
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tapestry-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tapestry-user-help@jakarta.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: tapestry-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tapestry-user-help@jakarta.apache.org