How to use Model Listeners in Liferay 7 DXP

How to use Model Listeners in Liferay 7 DXP ?

As we know that in liferay 7 or DXP everything is a declared as a component/module so to add a model listener in Liferay 7 we need to define the class as a component.

We will be using the @Component class and to declare the component/module. The service class need to be defined as the ModelListener class. The service class defines the types under which to register this Component as a service.

This will allow us to define the model listener which we want to listen to.

@Component(immediate = true, service = ModelListener.class)

We will be extending the BaseModelListener class and overriding the required methods.

Below is the code that can be used to implement the model listener for User model.

	package com.liferarevisited.model.listener;
	import org.osgi.service.component.annotations.Component;
	import com.liferay.portal.kernel.exception.ModelListenerException;
	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 CustomUserListener extends BaseModelListener<User> {
	@Override
	public void onAfterCreate(User model) throws ModelListenerException {
	System.out.println("CustomUserListener.onAfterCreate()");
	super.onAfterCreate(model);
	}
	@Override
	public void onAfterRemove(User model) throws ModelListenerException {
	System.out.println("CustomUserListener.onAfterRemove()");
	super.onAfterRemove(model);
	}
	@Override
	public void onAfterUpdate(User model) throws ModelListenerException {
	System.out.println("CustomUserListener.onAfterUpdate()");
	super.onAfterUpdate(model);
	}
	@Override
	public void onBeforeCreate(User model) throws ModelListenerException {
	System.out.println("CustomUserListener.onBeforeCreate()");
	super.onBeforeCreate(model);
	}
	@Override
	public void onBeforeRemove(User model) throws ModelListenerException {
	System.out.println("CustomUserListener.onBeforeRemove()");
	super.onBeforeRemove(model);
	}
	@Override
	public void onBeforeUpdate(User model) throws ModelListenerException {
	System.out.println("CustomUserListener.onBeforeUpdate()");
	super.onBeforeUpdate(model);
	}
	}

view raw CustomUserListener hosted with ❤ by GitHub

If we create a new user using the create account page or from the control panel we would see that the desired model is getting called.

We can see that while a user is getting created all the model listener methods that we had overridden are getting called.

For more details on the above topic please go through the below video on my youtube channel.

RELATED POSTS

http://www.liferayrevisited.com/2016/08/overriding-liferay-services-in-liferay-7.html

http://www.liferayrevisited.com/2016/08/creating-liferay-jsp-hook-with-liferay-7.html