Using custom services or liferay services in liferay themes (velocity templates)?

Question

How to use custom services method in liferay themes in velocity files like init_custom.vm, portal_normal.vm etc.

I see liferay provides a lot of variables of helper utility classes like $portalUtil for PortalUtil, $getterUtil for GetterUtil and so on, inside the init.vm file.

So is it possible to get instance of my custom services like an instance of com.my.custom.service.MyCustomLocalServiceImpl or services of liferay from UserLocalServiceImpl?

Here is some psuedo code, to give an idea of what I need:

// this code calls method from MyCustomLocalServiceImpl class to fetch items
#set ($listOfItems = $myCustomLocalServiceUtil.getAllItems())

// this code calls method from UserLocalServiceImpl class to fetch users
#set ($listOfUsers = $userLocalServiceUtil.getUsers(0, 99))

Environment: Liferay 6.1 CE GA1

Answer 1

It is possible.

1. The following code shows how to get the services:

   // Fetching instance of my custom services
   #set ($myCustomLocalService = $serviceLocator.findService('myCustomServices-portlet', 'com.my.custom.service.MyCustomLocalService'))
   
   // Fetching instance of UserLocalServiceImpl
   #set ($userLocalService = $serviceLocator.findService('com.liferay.portal.service.UserLocalService'))
   

2. Then simply call the service methods:

   #set ($listOfItems = $myCustomLocalService.getAllItems())
   
   #set ($listOfUsers = $userLocalService.getUsers(0, 99))
   

_{For Liferay 6.1 CE GA1: I found this class VelocityVariablesImpl (see methods like insertHelperUtilities, insertVariables) which actually makes all the variables and helper utilities available to the velocity templates.}

Answer 2

You can extend velocity context used in theme with custom variables and services using following hook plugin. Let's say you need to use your custom local service.

1. create a hook plugin with following liferay-hook.xml definition

   <hook>
       <portal-properties>portal.properties</portal-properties>
   </hook>
   

2. create portal.properties in main/resources (when you use maven) or in docroot/WEB-INF/src (when you use plugins sdk), place following configuration there

   servlet.service.events.pre=com.my.custom.action.MyCustomPreAction
   

3. create com.my.custom.action.MyCustomPreAction class in your hook that will extend com.liferay.portal.kernel.events.Action

4. implement run method

   @Override
   public void run(final HttpServletRequest request, final HttpServletResponse response)
       throws ActionException {
   
       Map<String, Object> vmVariables = (Map<String, Object>) request.getAttribute(WebKeys.VM_VARIABLES);
       if (vmVariables == null) {
         vmVariables = new HashMap<String, Object>(1);
       }
       vmVariables.put("myCustomServiceUtil", com.my.custom.service.MyCustomLocalServiceUtil.class);
       request.setAttribute(WebKeys.VM_VARIABLES, map);
   }
   

5. after your hook is deployed you can use your custom service in velocity template of your theme

   // this code calls method from MyCustomLocalServiceImpl class to fetch items
   #set ($listOfItems = $myCustomServiceUtil.getAllItems())