/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* Licensed 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.ext.dom;
import java.util.List;
import javax.xml.transform.TransformerException;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XBoolean;
import org.apache.xpath.objects.XNodeSet;
import org.apache.xpath.objects.XNull;
import org.apache.xpath.objects.XNumber;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XString;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeIterator;
import freemarker.core.Environment;
import freemarker.template.SimpleNumber;
import freemarker.template.SimpleScalar;
import freemarker.template.Template;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
/**
* Some glue code that bridges the Xalan XPath stuff (that is built into the JDK 1.4.x)
* with FreeMarker TemplateModel semantics
*/
class XalanXPathSupport implements XPathSupport {
private XPathContext xpathContext = new XPathContext();
/* I don't recommend Jaxen...
private static final String ERRMSG_RECOMMEND_JAXEN
= "(Note that there is no such restriction if you "
+ "configure FreeMarker to use Jaxen instead of Xalan.)";
*/
private static final String ERRMSG_EMPTY_NODE_SET
= "Cannot perform an XPath query against an empty node set."; /* " + ERRMSG_RECOMMEND_JAXEN;*/
synchronized public TemplateModel executeQuery(Object context, String xpathQuery) throws TemplateModelException {
if (!(context instanceof Node)) {
if (context != null) {
if (isNodeList(context)) {
int cnt = ((List) context).size();
if (cnt != 0) {
throw new TemplateModelException(
"Cannot perform an XPath query against a node set of " + cnt
+ " nodes. Expecting a single node."/* " + ERRMSG_RECOMMEND_JAXEN*/);
} else {
throw new TemplateModelException(ERRMSG_EMPTY_NODE_SET);
}
} else {
throw new TemplateModelException(
"Cannot perform an XPath query against a " + context.getClass().getName()
+ ". Expecting a single org.w3c.dom.Node.");
}
} else {
throw new TemplateModelException(ERRMSG_EMPTY_NODE_SET);
}
}
Node node = (Node) context;
try {
XPath xpath = new XPath(xpathQuery, null, customPrefixResolver, XPath.SELECT, null);
int ctxtNode = xpathContext.getDTMHandleFromNode(node);
XObject xresult = xpath.execute(xpathContext, ctxtNode, customPrefixResolver);
if (xresult instanceof XNodeSet) {
NodeListModel result = new NodeListModel(node);
result.xpathSupport = this;
NodeIterator nodeIterator = xresult.nodeset();
Node n;
do {
n = nodeIterator.nextNode();
if (n != null) {
result.add(n);
}
} while (n != null);
return result.size() == 1 ? result.get(0) : result;
}
if (xresult instanceof XBoolean) {
return ((XBoolean) xresult).bool() ? TemplateBooleanModel.TRUE : TemplateBooleanModel.FALSE;
}
if (xresult instanceof XNull) {
return null;
}
if (xresult instanceof XString) {
return new SimpleScalar(xresult.toString());
}
if (xresult instanceof XNumber) {
return new SimpleNumber(new Double(((XNumber) xresult).num()));
}
throw new TemplateModelException("Cannot deal with type: " + xresult.getClass().getName());
} catch (TransformerException te) {
throw new TemplateModelException(te);
}
}
private static PrefixResolver customPrefixResolver = new PrefixResolver() {
public String getNamespaceForPrefix(String prefix, Node node) {
return getNamespaceForPrefix(prefix);
}
public String getNamespaceForPrefix(String prefix) {
if (prefix.equals(Template.DEFAULT_NAMESPACE_PREFIX)) {
return Environment.getCurrentEnvironment().getDefaultNS();
}
return Environment.getCurrentEnvironment().getNamespaceForPrefix(prefix);
}
public String getBaseIdentifier() {
return null;
}
public boolean handlesNullPrefixes() {
return false;
}
};
/**
* Used for generating more intelligent error messages.
*/
private static boolean isNodeList(Object context) {
if (context instanceof List) {
List ls = (List) context;
int ln = ls.size();
for (int i = 0; i < ln; i++) {
if (!(ls.get(i) instanceof Node)) {
return false;
}
}
return true;
} else {
return false;
}
}
}