Ugo Cei wrote:
Let's assume I have a Person class:
public class Person {
public String getFirstname();
public String getLastname();
public Address getAddress();
...
}
and an Address class:
public class Address {
public String getStreet();
public String getTown();
...
}
I am building a form interface for editing a Person, with this binding:
<fb:value id="street" path="address/street"/>
Now, when trying to save the form, JXPath will do a
jxpathContext.createPathAndSetValue which will fail because
person.getAddress() is null and the JXPath context doesn't know how to
create an Address.
I could work around this problem by making sure person.address is not
null before loading it into the form, but I don't like this solution. A
better option, maybe, would be setting a factory on the context, like
is shown here: http://jakarta.apache.org/commons/jxpath/users-
guide.html#Creating%20Objects
My problem is: where do I set this factory in CForms, assuming this is
possible at all?
I do not think this is possible in current implementation (I am not sure
though). Still the approach implemented by JXPath does not scale well -
you would have to duplicate all info about relationships in your OR
model.
There is one more thing that is awkward with binding: imagine you have a
OR model with many-to-many relationship. Cforms will allow you to
create a form with a selection list to define those relationships. But
wait: what you get are the ids of entities not entities themselves.
Binding API does not give you access to service manager so you won't be
able to lookup some dao and load the entity by its id.
--
Leszek Gawron [EMAIL PROTECTED]
IT Manager MobileBox sp. z o.o.
+48 (61) 855 06 67 http://www.mobilebox.pl
mobile: +48 (501) 720 812 fax: +48 (61) 853 29 65
