Freemarker Support in WebWork

This document will focus on using the freemarker result since it is the recommended approach. An section follows to show how to use the FreemarkerServlet.

Configure your action to use the freemarker result type

The freemarker result type is defined in webwork-default.xml, so normally you just include it, and define your resutls to use type="freemarker".

<include file="webwork-default.xml"/>
...
<action name="test" class="package.Test">
  <result name="success" type="freemarker">/WEB-INF/views/testView.ftl</result>
</action>
...

Property Resoloution

for example ${name} will result in stack.findValue("name"), which generaly results in action.getName() being executed.

• freemarker variables
• value stack
• request attributes
• session attributes
• servlet context attributes

Objects in the Context

The following variables exist in the freemarer views

• req - the current HttpServletRequest
• res - the current HttpServletResponse
• stack - the current OgnlValueStack
• ognl - the OgnlTool instance
  • This class contains useful methods to execute OGNL expressions against arbitary objects, and a method to generate a select list using the <ww:select> pattern. (i.e. taking the name of the list property, a listKey and listValue)
• webwork - an instance of FreemarkerWebWorkUtil
• action - the current WebWork action
• exception - optional the Exception instance, if the view is a JSP exception or Servlet exception view

FreeMarker configuration with recent (post 2.1) releases

default_encoding=ISO-8859-1
template_update_delay=5
locale=no_NO

Using webwork UI tags - or any JSP Tag Library

<#assign ww=JspTaglibs["/WEB-INF/webwork.tld"] />

<@ww.form method="'post'" name="'inputform'" action="'save.action'" >
    <@ww.hidden name="'id'" />
    <@ww.textarea label="'Details'" name="'details'" rows=5 cols=40 />
    <@ww.submit value="'Save'" align="center" />
</@ww.form>

NOTE : numeric properties for tags MUST be numbers, not strings. as in the rows and cols properties above. if you use cols="40" you will receive an exception. Other than that, the freemarker tag container behaves as you would expect.

Using the FreemarkerServlet

The FreemarkerServlet provided in the freemarker.jar will work out of the box however it won't provide any webwork specific functionality such as the context variables, property resoloution etc. Therefore webwork provides its own servlet to provide this integration.

Register the FreemarkerServlet in web.xml

To use freemarker as a view engine, the webwork2 FreemarkerServlet needs to be configured, and mapped to the file extension that you use for your templates.

<servlet>
  <servlet-name>freemarker</servlet-name>
  <servlet-class>com.opensymphony.webwork.views.freemarker.FreemarkerServlet</servlet-class>
</servlet>

<servlet-mapping>
  <servlet-name>freemarker</servlet-name>
  <url-pattern>*.ftl</url-pattern>
</servlet-mapping>

Configure Actions to use this servlet (xwork.xml configuration)

<action name="test" class="package.Test">
  <result name="success" type="dispatcher">/WEB-INF/views/testView.ftl</result>
</action>

Extending the servlet

Please refer to the freemarker site for details about the base freemarker servlet.

protected TemplateModel createModel(
    ObjectWrapper wrapper, 
    ServletContext servletContext, 
    HttpServletRequest request, 
    HttpServletResponse response)

Please call super.createModel(...) and wrap it with a new model to avoid problems with action property resoloution.