001/**
002 * Copyright 2005-2014 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.rice.ken.xpath;
017
018import org.apache.commons.io.IOUtils;
019import org.apache.xerces.jaxp.JAXPConstants;
020import org.junit.Test;
021import org.kuali.rice.ken.test.KENTestCase;
022import org.kuali.rice.ken.util.DocumentNamespaceContext;
023import org.kuali.rice.ken.util.SimpleErrorHandler;
024import org.kuali.rice.ken.util.Util;
025import org.kuali.rice.test.BaselineTestCase.BaselineMode;
026import org.kuali.rice.test.BaselineTestCase.Mode;
027import org.w3c.dom.Document;
028import org.xml.sax.InputSource;
029
030import javax.xml.parsers.DocumentBuilder;
031import javax.xml.parsers.DocumentBuilderFactory;
032import javax.xml.xpath.XPath;
033import javax.xml.xpath.XPathConstants;
034import javax.xml.xpath.XPathFactory;
035import java.io.IOException;
036import java.io.InputStream;
037
038import static org.junit.Assert.assertEquals;
039
040
041/**
042 * Unit test that tests the affects of various document parsing (DocumentBuilderFactory)
043 * and XPath (XPath) flags, such as validation, namespace awareness, and namespace context.
044 * Lessons learned:
045 * <ul>
046 *   <li>DocumentBuilder namespace awareness needs to be turned on for validation to work</li>
047 *   <li>XPath absolutely requires a working NamespaceContext and qualified node names in expressions
048 *       if operating against a DOM which is the result of a validating parse</li>
049 *   <li>There is no apparent way to set the "default" namespace for XPath...so even when NamespaceContext
050 *       is set, nodes must be qualified.  The only way to obtain the "default" namespace is to explicitly
051 *       qualify with an empty namespace, e.g. /:notification/:channel (which is ugly and potentially confusing)</li>
052 *   <li>When deriving NamespaceContext from validated DOM, the "default" namespace must therefore be explicitly
053 *       registered with a prefix (which is redundant) so the NamespaceContext lookup can succeed.  The alternative
054 *       is to predefine the prefix in the NamespaceContent (which can be done by using a CompositeNamespaceContenxt
055 *       consisting of a ConfiguredNamespaceContext and a DocumentNamespaceContext).</li>
056 * </ul>
057 * @author Kuali Rice Team (rice.collab@kuali.org)
058 */
059@BaselineMode(Mode.CLEAR_DB)
060public class XPathTest extends KENTestCase {
061    private static final String TEST_XML = "sample_message_event_type.xml";
062
063    protected InputSource getTestXMLInputSource() {
064        InputStream is = XPathTest.class.getResourceAsStream(TEST_XML);
065        if (is != null) {
066            try {
067                LOG.info(IOUtils.toString(is));
068            } catch (IOException e) {
069                throw new RuntimeException(e);
070            } finally {
071                IOUtils.closeQuietly(is);
072            }
073
074            is = XPathTest.class.getResourceAsStream(TEST_XML);
075        }
076        return new InputSource(is);
077    }
078
079    protected XPath getXPath(Document doc) {
080        XPath xpath = XPathFactory.newInstance().newXPath();
081        if (doc != null) {
082            xpath.setNamespaceContext(new DocumentNamespaceContext(doc));
083        } else {
084            xpath.setNamespaceContext(Util.NOTIFICATION_NAMESPACE_CONTEXT);
085        }
086        return xpath;
087    }
088
089    protected Document getDocument(boolean namespaceAware, boolean validate) throws Exception {
090        // TODO: optimize this
091        final InputSource source = getTestXMLInputSource();
092        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
093        dbf.setValidating(validate);
094        dbf.setNamespaceAware(namespaceAware);
095        dbf.setAttribute(JAXPConstants.JAXP_SCHEMA_LANGUAGE, JAXPConstants.W3C_XML_SCHEMA);
096        DocumentBuilder db = dbf.newDocumentBuilder();
097        LOG.info("Setting entityresolver");
098        db.setEntityResolver(Util.getNotificationEntityResolver(services.getNotificationContentTypeService()));
099        db.setErrorHandler(new SimpleErrorHandler(LOG));
100        return db.parse(source);
101    }
102
103    @Test
104    public void testXPathWithPlainDOM() throws Exception {
105        Document doc = getDocument(false, false);
106        XPath xpath = getXPath(null);
107        String channelName = (String) xpath.evaluate("/notification/channel", doc.getDocumentElement(), XPathConstants.STRING);
108        assertEquals("Test Channel #1", channelName);
109    }
110    @Test
111    public void testXPathWithNamespaceAwareDOM() throws Exception {
112        Document doc = getDocument(true, false);
113        XPath xpath = getXPath(null);
114        String channelName = (String) xpath.evaluate("/nreq:notification/nreq:channel", doc.getDocumentElement(), XPathConstants.STRING);
115        assertEquals("Test Channel #1", channelName);
116    }
117    @Test
118    public void testXPathWithValidatedDOMFixedNamespace() throws Exception {
119        LOG.debug("TEST");
120        Document doc = getDocument(true, true);
121        LOG.info("Default namespace: " + doc.lookupNamespaceURI(null));
122        XPath xpath = getXPath(null);
123        String channelName = (String) xpath.evaluate("/nreq:notification/nreq:channel", doc.getDocumentElement(), XPathConstants.STRING);
124        assertEquals("Test Channel #1", channelName);
125    }
126    @Test
127    public void testXPathWithValidatedDOMDocNamespace() throws Exception {
128        LOG.debug("TEST");
129        Document doc = getDocument(true, true);
130        LOG.info("Default namespace: " + doc.lookupNamespaceURI(null));
131        LOG.info("default prefix: " + doc.lookupPrefix(doc.lookupNamespaceURI(null)));
132        XPath xpath = XPathFactory.newInstance().newXPath();
133        xpath.setNamespaceContext(Util.getNotificationNamespaceContext(doc));
134        String channelName = (String) xpath.evaluate("/nreq:notification/nreq:channel", doc.getDocumentElement(), XPathConstants.STRING);
135        assertEquals("Test Channel #1", channelName);
136    }
137}