Struts example source code file (Tree.java)

This example Struts source code file (Tree.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.

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The Struts Tree.java source code

/*
 * $Id: Tree.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.io.Writer;
import java.util.ArrayList;
import java.util.List;
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 widget with AJAX support.<p/>
 *
 * The "id "attribute is normally specified(recommended), such that it could be looked up using
 * javascript if necessary. The "id" attribute is required if the "selectedNotifyTopic" or the 
 * "href" attributes are going to be used.<p/>
 *
 * <!-- END SNIPPET: javadoc -->
 *
 * <!-- START SNIPPET: example1 -->
 * <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>
 * <!-- END SNIPPET: example1 -->
 * 
 * <!-- START SNIPPET: example2 -->
 * <s:tree
 *          id="..."
 *          rootNode="..."
 *          nodeIdProperty="..."
 *          nodeTitleProperty="..."
 *          childCollectionProperty="..." />
 * <!-- END SNIPPET: example2 -->
 * 
 * <!-- START SNIPPET: example3 -->
 * <s:url id="nodesUrl" namespace="/nodecorate" action="getNodes" />
 * <div style="float:left; margin-right: 50px;">
 *     <sx:tree id="tree" href="%{#nodesUrl}" />
 * </div>
 * 
 * On this example the url specified on the "href" attibute will be called to load
 * the elements on the root. The response is expected to be a JSON array of objects like:
 * [
 *      {
 *           label: "Node 1",
 *           hasChildren: false,
 *           id: "Node1"
 *      },
 *      {
 *           label: "Node 2",
 *           hasChildren: true,
 *           id: "Node2"
 *      },
 * ]
 * 
 * "label" is the text that will be displayed for the node. "hasChildren" marks the node has
 * having children or not (if true, a plus icon will be assigned to the node so it can be
 * expanded). The "id" attribute will be used to load the children of the node, when the node
 * is expanded. When a node is expanded a request will be made to the url in the "href" attribute
 * and the node's "id" will be passed in the parameter "nodeId".
 * 
 * The children collection for a node will be loaded only once, to reload the children of a 
 * node, use the "reload()" function of the treenode widget. To reload the children nodes of "Node1"
 * from the example above use the following javascript:
 * 
 * dojo.widget.byId("Node1").reload();
 * <!-- END SNIPPET: example3 -->
 */
@StrutsTag(name="tree", tldTagClass="org.apache.struts2.dojo.views.jsp.ui.TreeTag", description="Render a tree widget.")
public class Tree extends ClosingUIBean {

    private static final String TEMPLATE = "tree-close";
    private static final String OPEN_TEMPLATE = "tree";
    private final static transient Random RANDOM = new Random();    

    protected String toggle;
    protected String selectedNotifyTopics;
    protected String expandedNotifyTopics;
    protected String collapsedNotifyTopics;
    protected String rootNodeAttr;
    protected String childCollectionProperty;
    protected String nodeTitleProperty;
    protected String nodeIdProperty;
    protected String showRootGrid;

    protected String showGrid;
    protected String blankIconSrc;
    protected String gridIconSrcL;
    protected String gridIconSrcV;
    protected String gridIconSrcP;
    protected String gridIconSrcC;
    protected String gridIconSrcX;
    protected String gridIconSrcY;
    protected String expandIconSrcPlus;
    protected String expandIconSrcMinus;
    protected String iconWidth;
    protected String iconHeight;
    protected String toggleDuration;
    protected String templateCssPath;
    protected String href;
    protected String errorNotifyTopics;
    
    private List<String> childrenIds;
    
    public Tree(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
        super(stack, request, response);
    }

    public boolean start(Writer writer) {
        boolean result = super.start(writer);

        if (this.label == null && (href == null)) {
            if ((rootNodeAttr == null)
                    || (childCollectionProperty == null)
                    || (nodeTitleProperty == null)
                    || (nodeIdProperty == null)) {
                fieldError("label","The TreeTag requires either a value for 'label' or 'href' or ALL of 'rootNode', " +
                        "'childCollectionProperty', 'nodeTitleProperty', and 'nodeIdProperty'", null);
            }
        }
        return result;
    }

    protected void evaluateExtraParams() {
        super.evaluateExtraParams();

        if (toggle != null) {
            addParameter("toggle", findString(toggle));
        } else {
            addParameter("toggle", "fade");
        }

        if (selectedNotifyTopics != null) {
            addParameter("selectedNotifyTopics", findString(selectedNotifyTopics));
        }

        if (expandedNotifyTopics != null) {
            addParameter("expandedNotifyTopics", findString(expandedNotifyTopics));
        }

        if (collapsedNotifyTopics != null) {
            addParameter("collapsedNotifyTopics", findString(collapsedNotifyTopics));
        }

        if (rootNodeAttr != null) {
            addParameter("rootNode", findValue(rootNodeAttr));
        }

        if (childCollectionProperty != null) {
            addParameter("childCollectionProperty", findString(childCollectionProperty));
        }

        if (nodeTitleProperty != null) {
            addParameter("nodeTitleProperty", findString(nodeTitleProperty));
        }

        if (nodeIdProperty != null) {
            addParameter("nodeIdProperty", findString(nodeIdProperty));
        }

        if (showRootGrid != null) {
            addParameter("showRootGrid", findValue(showRootGrid, Boolean.class));
        }


        if (showGrid != null) {
            addParameter("showGrid", findValue(showGrid, Boolean.class));
        }

        if (blankIconSrc != null) {
            addParameter("blankIconSrc", findString(blankIconSrc));
        }

        if (gridIconSrcL != null) {
            addParameter("gridIconSrcL", findString(gridIconSrcL));
        }

        if (gridIconSrcV != null) {
            addParameter("gridIconSrcV", findString(gridIconSrcV));
        }

        if (gridIconSrcP != null)  {
            addParameter("gridIconSrcP", findString(gridIconSrcP));
        }

        if (gridIconSrcC != null) {
            addParameter("gridIconSrcC", findString(gridIconSrcC));
        }

        if (gridIconSrcX != null) {
            addParameter("gridIconSrcX", findString(gridIconSrcX));
        }

        if (gridIconSrcY != null) {
            addParameter("gridIconSrcY", findString(gridIconSrcY));
        }

        if (expandIconSrcPlus != null) {
            addParameter("expandIconSrcPlus", findString(expandIconSrcPlus));
        }

        if (expandIconSrcMinus != null) {
            addParameter("expandIconSrcMinus", findString(expandIconSrcMinus));
        }

        if (iconWidth != null) {
            addParameter("iconWidth", findValue(iconWidth, Integer.class));
        }
        if (iconHeight != null) {
            addParameter("iconHeight", findValue(iconHeight, Integer.class));
        }
        if (toggleDuration != null) {
            addParameter("toggleDuration", findValue(toggleDuration, Integer.class));
        }
        if (templateCssPath != null) {
            addParameter("templateCssPath", findString(templateCssPath));
        }
        if (href != null) 
            addParameter("href", findString(href));
        if (errorNotifyTopics != null)
            addParameter("errorNotifyTopics", findString(errorNotifyTopics));
                
        // 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);
        }
        
        if (this.childrenIds != null)
            addParameter("childrenIds", this.childrenIds);
    }
    
    public void addChildrenId(String id) {
        if (this.childrenIds == null)
            this.childrenIds = new ArrayList<String>();
        this.childrenIds.add(id);
    }

    @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;
    }

    public String getToggle() {
        return toggle;
    }

    @StrutsTagAttribute(description="The toggle property (either 'explode' or 'fade')", defaultValue="fade")
    public void setToggle(String toggle) {
        this.toggle = toggle;
    }

    @StrutsTagAttribute(description="Deprecated. Use 'selectedNotifyTopics' instead.")
    public void setTreeSelectedTopic(String selectedNotifyTopic) {
        this.selectedNotifyTopics = selectedNotifyTopic;
    }

    @StrutsTagAttribute(description="Deprecated. Use 'expandedNotifyTopics' instead.")
    public void setTreeExpandedTopics(String expandedNotifyTopic) {
        this.expandedNotifyTopics = expandedNotifyTopic;
    }

    @StrutsTagAttribute(description="Deprecated. Use 'collapsedNotifyTopics' instead.")
    public void setTreeCollapsedTopics(String collapsedNotifyTopic) {
        this.collapsedNotifyTopics = collapsedNotifyTopic;
    }

    public String getRootNode() {
        return rootNodeAttr;
    }

    @StrutsTagAttribute(description="The rootNode property.")
    public void setRootNode(String rootNode) {
        this.rootNodeAttr = rootNode;
    }

    public String getChildCollectionProperty() {
        return childCollectionProperty;
    }

    @StrutsTagAttribute(description="The childCollectionProperty property.")
    public void setChildCollectionProperty(String childCollectionProperty) {
        this.childCollectionProperty = childCollectionProperty;
    }

    public String getNodeTitleProperty() {
        return nodeTitleProperty;
    }

    @StrutsTagAttribute(description="The nodeTitleProperty property.")
    public void setNodeTitleProperty(String nodeTitleProperty) {
        this.nodeTitleProperty = nodeTitleProperty;
    }

    public String getNodeIdProperty() {
        return nodeIdProperty;
    }

    @StrutsTagAttribute(description="The nodeIdProperty property.")
    public void setNodeIdProperty(String nodeIdProperty) {
        this.nodeIdProperty = nodeIdProperty;
    }

    @StrutsTagAttribute(description="The showRootGrid property (default true).")
    public void setShowRootGrid(String showRootGrid) {
        this.showRootGrid = showRootGrid;
    }

    public String getShowRootGrid() {
        return showRootGrid;
    }

    public String getBlankIconSrc() {
        return blankIconSrc;
    }

    @StrutsTagAttribute(description="Blank icon image source.")
    public void setBlankIconSrc(String blankIconSrc) {
        this.blankIconSrc = blankIconSrc;
    }

    public String getExpandIconSrcMinus() {
        return expandIconSrcMinus;
    }

    @StrutsTagAttribute(description="Expand icon (-) image source.")
    public void setExpandIconSrcMinus(String expandIconSrcMinus) {
        this.expandIconSrcMinus = expandIconSrcMinus;
    }

    public String getExpandIconSrcPlus() {
        return expandIconSrcPlus;
    }

    @StrutsTagAttribute(description="Expand Icon (+) image source.")
    public void setExpandIconSrcPlus(String expandIconSrcPlus) {
        this.expandIconSrcPlus = expandIconSrcPlus;
    }

    public String getGridIconSrcC() {
        return gridIconSrcC;
    }

    @StrutsTagAttribute(description="Image source for under child item child icons.")
    public void setGridIconSrcC(String gridIconSrcC) {
        this.gridIconSrcC = gridIconSrcC;
    }

    public String getGridIconSrcL() {
        return gridIconSrcL;
    }


    @StrutsTagAttribute(description=" Image source for last child grid.")
    public void setGridIconSrcL(String gridIconSrcL) {
        this.gridIconSrcL = gridIconSrcL;
    }

    public String getGridIconSrcP() {
        return gridIconSrcP;
    }

    @StrutsTagAttribute(description="Image source for under parent item child icons.")
    public void setGridIconSrcP(String gridIconSrcP) {
        this.gridIconSrcP = gridIconSrcP;
    }

    public String getGridIconSrcV() {
        return gridIconSrcV;
    }

    @StrutsTagAttribute(description="Image source for vertical line.")
    public void setGridIconSrcV(String gridIconSrcV) {
        this.gridIconSrcV = gridIconSrcV;
    }

    public String getGridIconSrcX() {
        return gridIconSrcX;
    }

    @StrutsTagAttribute(description="Image source for grid for sole root item.")
    public void setGridIconSrcX(String gridIconSrcX) {
        this.gridIconSrcX = gridIconSrcX;
    }

    public String getGridIconSrcY() {
        return gridIconSrcY;
    }

    @StrutsTagAttribute(description="Image source for grid for last root item.")
    public void setGridIconSrcY(String gridIconSrcY) {
        this.gridIconSrcY = gridIconSrcY;
    }

    public String getIconHeight() {
        return iconHeight;
    }


    @StrutsTagAttribute(description="Icon height", defaultValue="18px")
    public void setIconHeight(String iconHeight) {
        this.iconHeight = iconHeight;
    }

    public String getIconWidth() {
        return iconWidth;
    }

    @StrutsTagAttribute(description="Icon width", defaultValue="19px")
    public void setIconWidth(String iconWidth) {
        this.iconWidth = iconWidth;
    }



    public String getTemplateCssPath() {
        return templateCssPath;
    }

    @StrutsTagAttribute(description="Template css path", defaultValue="{contextPath}/struts/tree.css.")
    public void setTemplateCssPath(String templateCssPath) {
        this.templateCssPath = templateCssPath;
    }

    public String getToggleDuration() {
        return toggleDuration;
    }

    @StrutsTagAttribute(description="Toggle duration in milliseconds", defaultValue="150")
    public void setToggleDuration(String toggleDuration) {
        this.toggleDuration = toggleDuration;
    }

    public String getShowGrid() {
        return showGrid;
    }

    @StrutsTagAttribute(description="Show grid", type="Boolean", defaultValue="true")
    public void setShowGrid(String showGrid) {
        this.showGrid = showGrid;
    }
    
    @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);
    }

    @StrutsTagAttribute(description="Comma separated lis of topics to be published when a node" +
                " is collapsed. An object with a 'node' property will be passed as parameter to the topics.")
    public void setCollapsedNotifyTopics(String collapsedNotifyTopics) {
        this.collapsedNotifyTopics = collapsedNotifyTopics;
    }

    @StrutsTagAttribute(description="Comma separated lis of topics to be published when a node" +
                " is expanded. An object with a 'node' property will be passed as parameter to the topics.")
    public void setExpandedNotifyTopics(String expandedNotifyTopics) {
        this.expandedNotifyTopics= expandedNotifyTopics;
    }

    @StrutsTagAttribute(description="Comma separated lis of topics to be published when a node" +
                " is selected. An object with a 'node' property will be passed as parameter to the topics.")
    public void setSelectedNotifyTopics(String selectedNotifyTopics) {
        this.selectedNotifyTopics = selectedNotifyTopics;
    }

    @StrutsTagAttribute(description="Url used to load the list of children nodes for an specific node, whose id will be " +
    		"passed as a parameter named 'nodeId' (empty for root)")
    public void setHref(String href) {
        this.href = href;
    }
    
    @StrutsTagAttribute(description="Comma delimmited list of topics that will published after the request(if the request fails)." +
    		"Only valid if 'href' is set")
    public void setErrorNotifyTopics(String errorNotifyTopics) {
        this.errorNotifyTopics = errorNotifyTopics;
    }
}