You can create a custom model listener in a module by following steps :
1. Create model listener class
Create a custom model listener class that extends BaseModelListener<T> as below
package ...;
import ...;
public class CustomModelListener extends BaseModelListener<CustomEntity> {
...
}
2. Register the model listener service
Register the model listener service with Liferay’s OSGi runtime by adding @Component annotation configuration as below
package ...;
import ...;
@Component(
immediate = true,
service = ModelListener.class
)
public class CustomModelListener extends BaseModelListener<CustomEntity> {
...
}
3. Listen for persistence events
Implement any methods of ModelListener interface and add your business logic into method body.
package ...;
import ...;
@Component(
immediate = true,
service = ModelListener.class
)
public class CustomModelListener extends BaseModelListener<CustomEntity> {
/*
* implement your desired methods of ModelListener interface to add your business logic
*/
}
The ModelListener interface provides a number of methods to listen for the model events
| onBeforeAddAssociation | If there’s an association between two models, use this method to do something before an association record is added. |
| onBeforeCreate | Use this method to do something before the persistence layer’s “create” method is called |
| onBeforeUpdate | Use this method to do something before the persistence layer’s “update” method is called |
| onBeforeRemoveAssociation | If there’s an association between two models, use this method to do something before a removal from the mapping table. |
| onBeforeRemove | Use this method to do something before the persistence layer’s “remove” method is called |
| onAfterAddAssociation | If there’s an association between two models, use this method to do something after an association record is added |
| onAfterCreate | Use this method to do something after the persistence layer’s “create” method is called. |
| onAfterUpdate | Use this method to do something after the persistence layer’s “update” method is called. |
| onAfterRemoveAssociation | If there’s an association between two models, use this method to do something after an association record is removed. |
| onAfterRemove | Use this method to do something after the persistence layer’s “remove” method is called. |
Please refer below example of Model Listener for User model
// CustomUserModelListener.java //
package ...;
import org.osgi.service.component.annotations.Component;
import com.liferay.portal.kernel.exception.ModelListenerException;
import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.model.BaseModelListener;
import com.liferay.portal.kernel.model.ModelListener;
import com.liferay.portal.kernel.model.User;
@Component(
immediate = true,
service = ModelListener.class
)
public class CustomUserModelListener extends BaseModelListener<User> {
private static final Log log = LogFactoryUtil.getLog(CustomUserMoledListener.class);
@Override
public void onBeforeCreate(User userModel) throws ModelListenerException {
log.info("in onBeforeCreate method");
log.info("userModel : " + userModel);
super.onBeforeCreate(userModel);
}
@Override
public void onAfterCreate(User userModel) throws ModelListenerException {
log.info("in onAfterCreate method");
log.info("userModel : " + userModel);
super.onAfterCreate(userModel);
}
}
You can test the given CustomUserModelListener by creating new user from Liferay control panel, You can see logs are getting printed in console when model listener is called.
