Model Listener Hook

                             Liferay Hook provide facility to create listener on particular model. We require to implement implements ModelListener on our custom class. Lets create one Hook which allow to do action on the various activity on particular model action.

• Create one hook.(e.g. UserListener-hook)

• Add portal properties inside liferay-hook.xml file under web inf. 

 <?xml version="1.0"?>  
 <!DOCTYPE hook PUBLIC "-//Liferay//DTD Hook 6.2.0//EN" "http://www.liferay.com/dtd/liferay-hook_6_2_0.dtd">  
 <hook>  
   <portal-properties>portal.properties</portal-properties>  
 </hook> 

•  It will create portal.properties inside src folder.

•  Add below property inside portlet.properties file

            value.object.listener.com.liferay.portal.model.User=com.sa.CreateAccountHook

In above property we have created listener for the User model

and we will  implements ModelListener on our custom class in my case it is com.sa.CreateAccountHook.

• Now create one custom class in your package which provide in  portlet.properties.

My case the package is com.sa

class CreateAccountHook.

• We will implements ModelListener on that. After implementing its method it will show like below.

 package com.sa;  
 import com.liferay.portal.ModelListenerException;  
 import com.liferay.portal.model.ModelListener;  
 import com.liferay.portal.model.User;  
 public class CreateAccountHook implements ModelListener {  
  @Override  
  public void onAfterAddAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onAfterCreate(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onAfterRemove(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onAfterRemoveAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onAfterUpdate(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeAddAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeCreate(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeRemove(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeRemoveAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeUpdate(Object arg0) throws ModelListenerException {  
  }  
 }  

• The each method will invoke after certain event on the User model. So for test the above listener lets add some code in the methods.

 package com.sa;  
 import com.liferay.portal.ModelListenerException;  
 import com.liferay.portal.model.ModelListener;  
 import com.liferay.portal.model.User;  
 public class CreateAccountHook implements ModelListener {  
  @Override  
  public void onAfterAddAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onAfterCreate(Object arg0) throws ModelListenerException {  
  User user = (User) arg0;  
  System.out.println("\n\t--------------- New user is user: "  
   + user.getEmailAddress() + " with id of: " + user.getUserId()  
   + "\n\n-------------------------");  
  }  
  @Override  
  public void onAfterRemove(Object arg0) throws ModelListenerException {  
  System.out.println("######USER REMOVED SUCCESSFULLY########");  
  System.out.println("######USER REMOVED SUCCESSFULLY########");  
  System.out.println("######USER REMOVED SUCCESSFULLY########");  
  System.out.println("######USER REMOVED SUCCESSFULLY########");  
  System.out.println("######USER REMOVED SUCCESSFULLY########");  
  System.out.println("######USER REMOVED SUCCESSFULLY########");  
  }  
  @Override  
  public void onAfterRemoveAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onAfterUpdate(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeAddAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeCreate(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeRemove(Object arg0) throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeRemoveAssociation(Object arg0, String arg1, Object arg2)  
   throws ModelListenerException {  
  }  
  @Override  
  public void onBeforeUpdate(Object arg0) throws ModelListenerException {  
  }  
 }  

• There are two methods we have added code inside it.

onAfterCreate 

The method will invoke after Creating User.

onAfterRemove

The method will invoke after removing User.

• Now Deploy our portlet. Create User in Liferay portal

It will invoke onAfterCreate method.

It will show message on console

        --------------- New user is user: test1@gmail.com with id of: 11609

-------------------------

• Now delete any User.

It will invoke onAfterRemove

It will show message on console

######USER REMOVED SUCCESSFULLY########
######USER REMOVED SUCCESSFULLY########
######USER REMOVED SUCCESSFULLY########
######USER REMOVED SUCCESSFULLY########
######USER REMOVED SUCCESSFULLY########
######USER REMOVED SUCCESSFULLY########

• We have implemented  inbuilt User object model listener similarly we can implement for the Role and other model.
• You can download source code from below link.

https://drive.google.com/file/d/0B9B1NsG0lyx6NC01eVJpOHllMm8/view?usp=sharing