src/site/apt/tutorial/integration/velocity.apt

~~ $Id$
~~
~~ Licensed to the Apache Software Foundation (ASF) under one
~~ or more contributor license agreements.  See the NOTICE file
~~ distributed with this work for additional information
~~ regarding copyright ownership.  The ASF licenses this file
~~ to you under the Apache License, Version 2.0 (the
~~ "License"); you may not use this file except in compliance
~~ with the License.  You may obtain a copy of the License at
~~
~~ http://www.apache.org/licenses/LICENSE-2.0
~~
~~ Unless required by applicable law or agreed to in writing,
~~ software distributed under the License is distributed on an
~~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
~~ KIND, either express or implied.  See the License for the
~~ specific language governing permissions and limitations
~~ under the License.
~~
         -----------
         Integration with Apache Velocity
         -----------

Integration with Apache Velocity

  {{{http://velocity.apache.org/}Apache Velocity}} is a templating framework
  that can be used as a replacement for JavaServer Pages (JSP). Tiles can be
  used with Velocity through the use of Tiles Velocity package.

* Configuration

  To use Velocity together with Tiles

  * Add Velocity (1.7 or better) and Velocity Tools (2.0 or better) jars to your application.

  * Add <<<tiles-template-x.x.x.jar>>> and <<<tiles-velocity-x.x.x.jar>>> files
  to your application.

  * To access ".vm" files from HTTP requests, add this piece of configuration in <<<web.xml>>>
  (the parameters can be modified as needed).

----------------------------------
<servlet>
  <servlet-name>velocity</servlet-name>
  <servlet-class>org.apache.velocity.tools.view.VelocityViewServlet</servlet-class>

  <init-param>
    <param-name>org.apache.velocity.toolbox</param-name>
    <param-value>/WEB-INF/tools.xml</param-value>
  </init-param>

  <init-param>
    <param-name>org.apache.velocity.properties</param-name>
    <param-value>/WEB-INF/velocity.properties</param-value>
  </init-param>
</servlet>
----------------------------------

  * To access ".vm" files as attributes, register VelocityAttributeRenderer
  this way (only available in a servlet environment):

----------------------------------
@Override
protected void registerAttributeRenderers(
        BasicRendererFactory rendererFactory, TilesApplicationContext applicationContext,
        TilesRequestContextFactory contextFactory,
        TilesContainer container, AttributeEvaluator evaluator) {
    super.registerAttributeRenderers(rendererFactory, applicationContext, contextFactory,
            container, evaluator);

    VelocityAttributeRenderer velocityRenderer = new VelocityAttributeRenderer();
    velocityRenderer.setApplicationContext(applicationContext);
    velocityRenderer.setEvaluator(evaluator);
    velocityRenderer.setRequestContextFactory(contextFactory);
    velocityRenderer.setParameter("org.apache.velocity.toolbox", "/WEB-INF/tools.xml");
    velocityRenderer.setParameter("org.apache.velocity.properties", "/WEB-INF/velocity.properties");
    velocityRenderer.commit();
    rendererFactory.registerRenderer("velocity", velocityRenderer);
}
----------------------------------

  This way you can specify an attribute that is rendered directly using this syntax:

----------------------------------
<put-attribute name="myAttribute" value="/pages/myPage.vm" type="velocity" />
----------------------------------

* Usage in Velocity templates

  There are two Velocity tools that will be available to your application:

  * the <<<tilesAlt>>> tool, that is a Velocity-style tool:

----------------------------------
$tilesAlt.startAttributeContext()
$set($templateAttribute = $tilesAlt.createTemplateAttribute("/page/myTemplate.vm"))
$set($attributeContext = $tilesAlt.getAttributeContext())
  $set($attribute = $tilesAlt.createAttribute())
  $attribute.setValue("This is the title.")
  $attributeContext.putAttribute("title", $attribute})

  $set($attribute = $tilesAlt.createAttribute())
  $attribute.setValue("/velocity/header.vm")
  $attribute.setRenderer("velocity")
  $attributeContext.putAttribute("header", $attribute})

  $set($attribute = $tilesAlt.createAttribute())
  $attribute.setValue("/velocity/body.vm")
  $attribute.setRenderer("velocity")
  $attributeContext.putAttribute("body", $attribute})

$tilesAlt.renderAttribute($templateAttribute)
$tilesAlt.endAttributeContext()
----------------------------------

  * the <<<tiles>>> tool, that has both Velocity-style methods and directive oriented methods.

----------------------------------
$tiles.insertTemplate.start({"template":"/page/myTemplate.vm"})
  $tiles.putAttribute({"name":"title", "value":"This is the title."})
  $tiles.putAttribute({"name":"header", "value":"/velocity/header.vm", "type":"velocity"})
  $tiles.putAttribute({"name":"body", "value":"/velocity/body.vm", "type":"velocity"})
$tiles.insertTemplate().end()
----------------------------------

  For details about directives see the {{{../../apidocs/index.html}Javadocs}}.