Hi Andreas! When I emailed to Tapestry's list I was prototyping a project. Now I'm actually developing it and I'm very interested in getting this service working.
Did you find some code where you used this feature? Thanks! Marcos On 6/29/07, Marcos Chicote <[EMAIL PROTECTED]> wrote:
Thanks Andreas. I have to do some more reading then. I you have some code that I can use as an example I would be really grateful. Thanks! Marcos On 6/29/07, Andreas Andreou <[EMAIL PROTECTED]> wrote: > > O/H Marcos Chicote έγραψε: > > Thanks Andreas. > > Before mailing to this list, I tried looking at the ognl documentation > > and I > > found the NullHandler interface but I wasn't sure how it worked with > > Tapestry or if it was possible to do it another way without altering > the > > BOs. > > > > Correct me if I'm wrong but what I understand is that Tapestry already > > implements a Hivemind service that does the null handling. All I have > > to do > > is make my BOs implement NullHandler interface. Am I right? > Hmmm, not really... Tapestry simply provides that point so that your > have a global > way of registring handlers - so, making your BOs implement NullHandler > is not enough > > Also, i'm not sure if that's the correct approach - seems it polutes > your BOs > > I think I'd create a service that would be able to null-handle your > specific objects, and > esp. of all those objects have a common superclass, i'd be able to > register them all at once. > > I'll dig in for some code - it's been a while since i last used this > > > > > Thanks a lot! > > > > Marcos > > > > On 6/29/07, Andreas Andreou <[EMAIL PROTECTED]> wrote: > >> > >> > >> > http://tapestry.apache.org/tapestry4.1/tapestry-framework/hivedoc/config/tapestry.ognl.NullHandlers.html > >> > >> > >> the way it works, is that you associate implementations of > >> http://www.ognl.org/2.6.9/Documentation/javadoc/ognl/NullHandler.html > >> with class types whose methods (or properties) may return null > >> > >> O/H Marcos Chicote έγραψε: > >> > Hi! > >> > I have a Table component (actually I have TableRows, TableView, and > >> all > >> > those other components that form a Table) and one of the columns in > >> > TableView is declared like this: columnName: > object1.object2.property. > >> > > >> > As you can see this can throw NullPointerException if either > >> object1 or > >> > object2 are null. > >> > > >> > To solve this problem, I have to alternatives: > >> > a) Use a Block component called columnNameColumnValue an inside the > >> > block an > >> > Insert component with a value asociated with the page's class that > >> > handles > >> > nulls > >> > b) Declare the column like: columnName:object1.propertyObject2. > (that > >> > it a > >> > getPropertyObject2 method in object1 class that handles nulls). > >> > > >> > Is there a better way to solve this?? I would love something like a > >> > prefix > >> > that allows me to specify that whenever a NPE is found, a blank > >> space is > >> > rendered. Is something like that possible? > >> > > >> > I'm ussing Tapestry 4.1.1. > >> > > >> > Btw, great work with Tap4.1.2, congratulations! > >> > > >> > Thanks! > >> > > >> > >> -- > >> Andreas Andreou - [EMAIL PROTECTED] - http://andyhot.di.uoa.gr > >> Tapestry / Tacos developer > >> Open Source / J2EE Consulting > >> > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: [EMAIL PROTECTED] > >> For additional commands, e-mail: [EMAIL PROTECTED] > >> > >> > > -- > Andreas Andreou - [EMAIL PROTECTED] - http://andyhot.di.uoa.gr > Tapestry / Tacos developer > Open Source / J2EE Consulting > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > >
