Recent Bloggers

Olaf Kock

90 Publications
18 décembre 2014

David Kubitza

2 Publications
14 décembre 2014

Meera Prince

19 Publications
4 décembre 2014

James Falkner

100 Publications
2 décembre 2014

Juan Fernández

17 Publications
28 novembre 2014

Andrea Di Giorgi

2 Publications
26 novembre 2014

Gregory Amerson

26 Publications
25 novembre 2014

Cody Hoag

6 Publications
25 novembre 2014

Duke H

2 Publications
24 novembre 2014

Nicholas Gaskill

1 Publications
21 novembre 2014

Exception Handling in Velocity Templates

General Blogs 28 avril 2014 Par Parth Ghaswala

Hi Guys,

I am using Liferay 6.1.

Recently I faced an issue, which kept me wondering for getting tricks to handle exceptions in velocity file.

Ideally we can't do any exception handling directly to .vm files.

But here is the trick to get it done:

Using Service-Pre-Action hook, we can achieve this.

Step 1 : Create ServicePreAction hook

public class MyServicePreAction extends Action {

       public void run(HttpServletRequest request, HttpServletResponse response)
            throws ActionException


                        Map<String, Object> vmVariables = new HashMap<String, Object>();
                       vmVariables.put("customVelocityVariable", new MyServicePreAction());

                       request.setAttribute(WebKeys.VM_VARIABLES, vmVariables);


    public String myFunctionCalledFromVM (String param1, int param2, int param3)



                     //Business logic for which exception handling needed to be done at velocity files, is                                     // to be written here.


             catch(Exception e)





Step 2 Call ServicePreAction Fuction to Velocity File:

Object of MyServicePreAction gets registered to Velocity Variables pool with name of customVelocityVariable, as coded above.

Now user can call function myFunctionCalledFromVM (........) with customVelocityVariable in .vm files as below:


If any exception occurs at this call, that gets handled in Service PreAction hook. And finally we got exception handling done for our velocity files bussiness logics.

Here what ever logic you are supposed to put at .vm files, put that to this myFunctionCalledFromVM().

Hope this helps you.


Affichage de 1 résultat(s).