package org.apache.velocity.runtime.directive;
/*
* 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.
*/
import java.io.Writer;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.exception.TemplateInitException;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.runtime.log.Log;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.parser.node.Node;
/**
* Directive that puts an unrendered AST block in the context
* under the specified key, postponing rendering until the
* reference is used and rendered.
*
* @author Andrew Tetlaw
* @author Nathan Bubna
* @version $Id: Define.java 686842 2008-08-18 18:29:31Z nbubna $
*/
public class Define extends Block
{
/**
* Return name of this directive.
*/
public String getName()
{
return "define";
}
/**
* simple init - get the key
*/
public void init(RuntimeServices rs, InternalContextAdapter context, Node node)
throws TemplateInitException
{
super.init(rs, context, node);
// the first child is the block name (key), the second child is the block AST body
if ( node.jjtGetNumChildren() != 2 )
{
throw new VelocityException("parameter missing: block name at "
+ Log.formatFileString(this));
}
/*
* first token is the name of the block. We don't even check the format,
* just assume it looks like this: $block_name. Should we check if it has
* a '$' or not?
*/
key = node.jjtGetChild(0).getFirstToken().image.substring(1);
/*
* default max depth of two is used because intentional recursion is
* unlikely and discouraged, so make unintentional ones end fast
*/
maxDepth = rs.getInt(RuntimeConstants.DEFINE_DIRECTIVE_MAXDEPTH, 2);
}
/**
* directive.render() simply makes an instance of the Block inner class
* and places it into the context as indicated.
*/
public boolean render(InternalContextAdapter context, Writer writer, Node node)
{
/* put a Block.Reference instance into the context,
* using the user-defined key, for later inline rendering.
*/
context.put(key, new Reference(context, this));
return true;
}
}
|