001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry.contrib.ajax;
016
017import java.io.IOException;
018import java.io.OutputStream;
019import java.io.StringWriter;
020import java.util.HashMap;
021import java.util.Map;
022
023import javax.xml.parsers.DocumentBuilder;
024import javax.xml.parsers.DocumentBuilderFactory;
025import javax.xml.transform.OutputKeys;
026import javax.xml.transform.Transformer;
027import javax.xml.transform.TransformerFactory;
028import javax.xml.transform.dom.DOMSource;
029import javax.xml.transform.stream.StreamResult;
030
031import org.apache.hivemind.ApplicationRuntimeException;
032import org.apache.hivemind.util.Defense;
033import org.apache.tapestry.IComponent;
034import org.apache.tapestry.IPage;
035import org.apache.tapestry.IRequestCycle;
036import org.apache.tapestry.engine.IEngineService;
037import org.apache.tapestry.engine.ILink;
038import org.apache.tapestry.error.RequestExceptionReporter;
039import org.apache.tapestry.services.LinkFactory;
040import org.apache.tapestry.services.ServiceConstants;
041import org.apache.tapestry.util.ContentType;
042import org.apache.tapestry.web.WebResponse;
043import org.w3c.dom.Document;
044import org.w3c.dom.Node;
045
046/**
047 * @author mindbridge
048 * @author Paul Green
049 * @since 4.0
050 */
051public class XTileService implements IEngineService
052{
053    public static final String SERVICE_NAME = "xtile";
054
055    private RequestExceptionReporter _exceptionReporter;
056
057    private WebResponse _response;
058
059    private LinkFactory _linkFactory;
060
061    public String getName()
062    {
063        return SERVICE_NAME;
064    }
065
066    public ILink getLink(boolean post, Object parameter)
067    {
068        Defense.isAssignable(parameter, IComponent.class, "parameter");
069
070        IComponent component = (IComponent) parameter;
071
072        Map parameters = new HashMap();
073        parameters.put(ServiceConstants.PAGE, component.getPage().getPageName());
074        parameters.put(ServiceConstants.COMPONENT, component.getIdPath());
075
076        return _linkFactory.constructLink(this, false, parameters, false);
077    }
078
079    public void service(IRequestCycle cycle) throws IOException
080    {
081        String pageName = cycle.getParameter(ServiceConstants.PAGE);
082        String componentId = cycle.getParameter(ServiceConstants.COMPONENT);
083
084        IPage componentPage = cycle.getPage(pageName);
085        IComponent component = componentPage.getNestedComponent(componentId);
086
087        if (!(component instanceof IXTile))
088            throw new ApplicationRuntimeException("Incorrect component type: was "
089                    + component.getClass() + " but must be " + IXTile.class, component, null, null);
090
091        IXTile xtile = (IXTile) component;
092
093        String[] params = cycle.getParameters(ServiceConstants.PARAMETER);
094        cycle.setListenerParameters(params);
095
096        xtile.trigger(cycle);
097
098        // do not squeeze on output either
099        Object[] args = cycle.getListenerParameters();
100        String strArgs = generateOutputString(args);
101        if (strArgs != null)
102        {
103            OutputStream output = _response.getOutputStream(new ContentType("text/xml"));
104            output.write(strArgs.getBytes("utf-8"));
105        }
106    }
107
108    protected String generateOutputString(Object[] args)
109    {
110        try
111        {
112            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
113            dbf.setValidating(false);
114            DocumentBuilder db = dbf.newDocumentBuilder();
115            Document doc = db.newDocument();
116
117            Node rootNode = doc.createElement("data");
118            doc.appendChild(rootNode);
119
120            if (args != null)
121            {
122                for (int i = 0; i < args.length; i++)
123                {
124                    Object value = args[i];
125
126                    Node spNode = doc.createElement("sp");
127                    rootNode.appendChild(spNode);
128
129                    Node valueNode = doc.createTextNode(value.toString());
130                    spNode.appendChild(valueNode);
131                }
132            }
133
134            TransformerFactory trf = TransformerFactory.newInstance();
135            Transformer tr = trf.newTransformer();
136            tr.setOutputProperty(OutputKeys.INDENT, "yes");
137
138            DOMSource domSrc = new DOMSource(doc);
139            StringWriter writer = new StringWriter();
140            StreamResult res = new StreamResult(writer);
141            tr.transform(domSrc, res);
142            writer.close();
143
144            return writer.toString();
145        }
146        catch (Exception e)
147        {
148            _exceptionReporter.reportRequestException("Cannot generate XML", e);
149            return null;
150        }
151    }
152
153    public void setExceptionReporter(RequestExceptionReporter exceptionReporter)
154    {
155        _exceptionReporter = exceptionReporter;
156    }
157
158    public void setResponse(WebResponse response)
159    {
160        _response = response;
161    }
162
163    public static void main(String[] args)
164    {
165        XTileService objService = new XTileService();
166        System.out.println(objService.generateOutputString(new Object[]
167        { "test > work", new Integer(20) }));
168    }
169
170    public void setLinkFactory(LinkFactory linkFactory)
171    {
172        _linkFactory = linkFactory;
173    }
174
175}