freemarker.template.TemplateNodeModel Maven / Gradle / Ivy
/*
* 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.
*/
package freemarker.template;
/**
* "node" template language data type: an object that is a node in a tree.
* A tree of nodes can be recursively visited using the <#visit...> and <#recurse...>
* directives. This API is largely based on the W3C Document Object Model
* (DOM) API. However, it's meant to be generally useful for describing
* any tree of objects that you wish to navigate using a recursive visitor
* design pattern (or simply through being able to get the parent
* and child nodes).
*
* See the XML
* Processing Guide for a concrete application.
*
* @since FreeMarker 2.3
*/
public interface TemplateNodeModel extends TemplateModel {
/**
* @return the parent of this node or null, in which case
* this node is the root of the tree.
*/
TemplateNodeModel getParentNode() throws TemplateModelException;
/**
* @return a sequence containing this node's children.
* If the returned value is null or empty, this is essentially
* a leaf node.
*/
TemplateSequenceModel getChildNodes() throws TemplateModelException;
/**
* @return a String that is used to determine the processing
* routine to use. In the XML implementation, if the node
* is an element, it returns the element's tag name. If it
* is an attribute, it returns the attribute's name. It
* returns "@text" for text nodes, "@pi" for processing instructions,
* and so on.
*/
String getNodeName() throws TemplateModelException;
/**
* @return a String describing the type of node this is.
* In the W3C DOM, this should be "element", "text", "attribute", etc.
* A TemplateNodeModel implementation that models other kinds of
* trees could return whatever it appropriate for that application. It
* can be null, if you don't want to use node-types.
*/
String getNodeType() throws TemplateModelException;
/**
* @return the XML namespace URI with which this node is
* associated. If this TemplateNodeModel implementation is
* not XML-related, it will almost certainly be null. Even
* for XML nodes, this will often be null.
*/
String getNodeNamespace() throws TemplateModelException;
}