DataModel/dataTable for rendering 2 tables

[mpw]

I am trying to develope a Real Estate System with Sellers and
their listings. I have one-to-many Sellers to Listings. I am
having a problem rendering in via JSF/Facelets a DataTable
that display fields from both tables ie Seller and Listings.

I am using a Join Fetch to join all sellers that have listings. I can
see from log.info that the query works and all fields from both
tables are being pulled from the database.

in my JSF page i can say:

sellers.firstname
sellers.lastname
etc. which works fine

when i try sellers.listings.mls

this does not work and i get an error that 'mls' is an unknown
field. If i try other fields from the listings table the same results.

Is it possible to render fields from 2 tables via the dataTable and
if so what is the way to do it?



- Michael

[trickyvail]

I think you are trying to call getMls() on the listings collection inside Sellers. The collection does not have this method. You will first need to use a jsf iteration tag like h:dataTable, ui:repeat or rich:dataTable. Something like this:

<ui:repeat value=#{somebean.sellers} var="seller">
 <h:outputText value="#{seller.name}">
 <ui:repeat value="#{seller.listings}" var="listing">
 <h:outputText value="#{listing.mls}"/>
 </ui:repeat>
</ui:repeat>

[mpw]

thanks for the reply. however, i need to use the DataModel because
i will be also using @DataModelSelection to show the
detail of the selected row of the record.

Yes, i have getter and setter methods for 'mls' and my
other fields as well.


Michael

[trickyvail]

Just a hunch here, but is your collection a Set? JSF does not iterate correctly through sets. If you are using a set, try changing it to a List, or creating a transient method that instantiates and returns a new ArrayList constructed from the set.

[mpw]

yes, I am using a 'Set' as my many entity. I will change it to a List
and see what happens.

the question is should 'datatable' be able to iterate through the
'many' section of the one-to-many relationship ie fields from both
tables or should i be using another approach?!

thanks again.

Michael

[trickyvail]

Yes, DataTable can iterate through a One to Many collection of an entity. However there are limitations to what kinds of collections are acceptable. Lists and Arrays are allowed, Sets are not (because they are unordered).

[trickyvail]

Just found a JSF forum posting about this:

http://forum.java.sun.com/thread.jspa?threadID=589709&messageID=3062225

[mpw]

this is very interesting.

I was unaware that JSF with seam datatable needed to access
the rows via the indices which in a way sounds reasonable.


Note:

Looking through all the Seam examples i was not able to find an
example of an application using the DataTable accessing fields
from both entities with the one-to-many relationship.

thanks much for the pointer.

Michael