Struts example source code file (TreeNode.java)

This example Struts source code file (TreeNode.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

http, open_template, override, random, random, render, request, response, servlet, string, string, strutstagattribute, strutstagattribute, template, the, the, tree, treenode, util

The Struts TreeNode.java source code

/*
 * $Id: TreeNode.java 651946 2008-04-27 13:41:38Z apetrelli $
 *
 * 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 org.apache.struts2.dojo.components;

import java.util.Random;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.components.ClosingUIBean;
import org.apache.struts2.views.annotations.StrutsTag;
import org.apache.struts2.views.annotations.StrutsTagAttribute;
import org.apache.struts2.views.annotations.StrutsTagSkipInheritance;

import com.opensymphony.xwork2.util.ValueStack;

/**
 * <!-- START SNIPPET: javadoc -->
 *
 * Renders a tree node within a tree widget with AJAX support.<p/>
 *
 * Either of the following combinations should be used depending on if the tree
 * is to be constructed dynamically or statically. <p/>
 *
 * <b>Dynamically:
 * <ul>
 *      <li>id - id of this tree node
 *      <li>title - label to be displayed for this tree node
 * </ul>
 *
 * <b>Statically:
 * <ul>
 *      <li>rootNode - the parent node of which this tree is derived from
 *      <li>nodeIdProperty - property to obtained this current tree node's id
 *      <li>nodeTitleProperty - property to obtained this current tree node's title
 *      <li>childCollectionProperty - property that returnds this current tree node's children
 * </ul>
 *
 * <!-- END SNIPPET: javadoc -->
 *
 * <p/> Examples
 *
 * <pre>
 * <!-- START SNIPPET: example -->
 *
 * <-- Creating tree statically using hard-coded data. -->
 * <s:tree id="..." label="...">
 *    <s:treenode id="..." label="..." />
 *    <s:treenode id="..." label="...">
 *        <s:treenode id="..." label="..." />
 *        <s:treenode id="..." label="..." />
 *    </s:treenode>
 *    <s:treenode id="..." label="..." />
 * </s:tree>
 *
 * <-- Creating tree dynamically using data from backing action. -->
 * <s:tree
 *          id="..."
 *          rootNode="..."
 *          nodeIdProperty="..."
 *          nodeTitleProperty="..."
 *          childCollectionProperty="..." />
 *
 * <!-- END SNIPPET: example -->
 * </pre>
 *
 */
@StrutsTag(name="treenode", tldTagClass="org.apache.struts2.dojo.views.jsp.ui.TreeNodeTag", description="Render a tree node within a tree widget.")
public class TreeNode extends ClosingUIBean {
    private static final String TEMPLATE = "treenode-close";
    private static final String OPEN_TEMPLATE = "treenode";
    private final static transient Random RANDOM = new Random();    

    public TreeNode(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
        super(stack, request, response);
    }

    @Override
    @StrutsTagSkipInheritance
    public void setTheme(String theme) {
        super.setTheme(theme);
    }
    
    @Override
    public String getTheme() {
        return "ajax";
    }

    public String getDefaultOpenTemplate() {
        return OPEN_TEMPLATE;
    }

    protected String getDefaultTemplate() {
        return TEMPLATE;
    }

    protected void evaluateExtraParams() {
        super.evaluateExtraParams();
        
        // generate a random ID if not explicitly set and not parsing the content
        Boolean parseContent = (Boolean)stack.getContext().get(Head.PARSE_CONTENT);
        boolean generateId = (parseContent != null ? !parseContent : true);

        addParameter("pushId", generateId);
        if ((this.id == null || this.id.length() == 0) && generateId) {
            // resolves Math.abs(Integer.MIN_VALUE) issue reported by FindBugs 
            // http://findbugs.sourceforge.net/bugDescriptions.html#RV_ABSOLUTE_VALUE_OF_RANDOM_INT
            int nextInt = RANDOM.nextInt();
            nextInt = nextInt == Integer.MIN_VALUE ? Integer.MAX_VALUE : Math.abs(nextInt);  
            this.id = "widget_" + String.valueOf(nextInt);
            addParameter("id", this.id);
        }
        
        Tree parentTree = (Tree) findAncestor(Tree.class);
        parentTree.addChildrenId(this.id);
    }
    
    @StrutsTagAttribute(description="Label expression used for rendering tree node label.", required=true)
    public void setLabel(String label) {
        super.setLabel(label);
    }
    
    @StrutsTagAttribute(description="The css class to use for element")
    public void setCssClass(String cssClass) {
        super.setCssClass(cssClass);
    }

    @StrutsTagAttribute(description="The css style to use for element")
    public void setCssStyle(String cssStyle) {
        super.setCssStyle(cssStyle);
    }

    @StrutsTagAttribute(description="The id to use for the element")
    public void setId(String id) {
        super.setId(id);
    }

    @StrutsTagAttribute(description="The name to set for element")
    public void setName(String name) {
        super.setName(name);
    }
}