Wire Spring Beans

After registering beans for service classes, we can "wire" them in our controllers with ZK's variable resolver. To wire a Spring bean in a composer, we need to apply a org.zkoss.zkplus.spring.DelegatingVariableResolver. Then, we can apply annotation @WireVariable on a variable which we want to wire a Spring bean with. ZK will then wire the corresponding Spring bean with the variable whose name is the same as the bean's name. Alternatively, you can specify the bean's name with @WireVariable("beanName").

You might think why don't we just register our controllers(or ViewModels) as Spring beans, so that we can use Spring's @Autowire. We don't recommend to do so. The main reason is that none of Spring bean's scope matches ZK's composer's life cycle, for details please refer to Developer's Reference.

Wire beans in a composer

@VariableResolver(org.zkoss.zkplus.spring.DelegatingVariableResolver.class)
public class SidebarChapter4Controller extends SelectorComposer<Component>{

    private static final long serialVersionUID = 1L;

    //wire components
    @Wire
    Grid sidebar;

    //wire service
    @WireVariable("sidebarPageConfigPagebase")
    SidebarPageConfig pageConfig;

    ...
}

• Line 11: Specify bean's name sidebarPageConfigPagebase

Wire beans in a ViewModel

@VariableResolver(org.zkoss.zkplus.spring.DelegatingVariableResolver.class)
public class ProfileViewModel implements Serializable{
    private static final long serialVersionUID = 1L;

    //wire services
    @WireVariable
    AuthenticationService authService;
    @WireVariable
    UserInfoService userInfoService;
    ...
}

• Line 6: Wire a Spring bean whose bean name is authService.

Wire Manually

When using @WireVariable out of a composer (or a ViewModel), ZK will not wire Spring beans for you automatically. If you need to get a Spring bean, you can wire them manually. The example below wires a Spring bean in a page initiator:

@VariableResolver(org.zkoss.zkplus.spring.DelegatingVariableResolver.class)
public class AuthenticationInit implements Initiator {

    @WireVariable
    AuthenticationService authService;

    public void doInit(Page page, Map<String, Object> args) throws Exception {
        //wire service manually by calling Selectors API
        Selectors.wireVariables(page, this, Selectors.newVariableResolvers(getClass(), null));

        UserCredential cre = authService.getUserCredential();
        if(cre==null || cre.isAnonymous()){
            Executions.sendRedirect("/chapter8/login.zul");
            return;
        }
    }
}

• Line 9: After applying @VariableResolver and @WireVariable, use org.zkoss.zk.ui.select.Selectors to wire Spring beans manually.

After completing above steps, integration of Spring is done. The application's appearance doesn't change, but its infrastructure is now managed by Spring. You can visit http://localhost:8080/zkessentials to see the result.