hi!
so, im using wicket together with guice for DI.
i really wondered that the correct approach is here.
at first i thought it way easy to do this, but it turns out it is more
complicated..- at least more complicated to understand.
my typical page looks like this:
public class StartPage extends WebPage {
private transient EmkDao dao;
@Inject
public void setDao(EmkDao dao) {
this.dao = dao;
}
public EmkDao getDao() {
return dao;
}
public Start() {
add( Components that use the dao in various ways (models, onclick etc);
}
}
this seems to work well, in simple cases. BUT! as soon as i press
browser-back and reload most likely the dao member has become null. -> NPE
the expected behavior would be: transient fields are re-injected
whenever the page is deserialized. obviously this is not the case.
im surprised, that my StartPage is often a different instance (as seen
in the debugger) , when using browser-back-reload, but the setter
annotated with @Inject is not called twice.
since WebPage is Serializable and most injected objects are not (they
often contain references to non-serializable classes) they have to be
declared transient.
I use the following guice config:
<filter>
<filter-name>WicketApplication</filter-name>
<filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>
<init-param>
<param-name>applicationFactoryClassName</param-name>
<param-value>org.apache.wicket.guice.GuiceWebApplicationFactory</param-value>
</init-param>
<init-param>
<param-name>injectorContextAttribute</param-name>
<param-value>com.google.inject.Injector</param-value>
</init-param>
</filter>
with
bind(WebApplication.class).to(MyWicketApplication.class) in my Module.
i also tried the configuration described at
http://www.wideplay.com/wicketwithwarp-servlet with a simple
WicketFilter (without the GuiceWebApplicationFactory) and
Integrathe.with(this) in the WicketApplication, with the same result.
As I'm writing this mail, it turns out, it appears to work if i just
omit the "transient" keyword.
i wonder: what will that do to wicket pages? will i prevent them to
serialize any more? why doesn't it throw a NotSerializableException ?
then i have to use
@SuppressWarnings({"NonSerializableFieldInSerializableClass"}) for
IntelliJ to omit the warning.
somehow i am missing a coherent documentation on wicket+IoC on this matter.
best regards,
Andreas
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org
