Mega Code Archive
Set a namespaceprefix on an element if it is not set already
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/**
* 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.
*/
import javax.xml.XMLConstants;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
/**
* Few simple utils to read DOM. This is originally from the Jakarta Commons Modeler.
*
* @author Costin Manolache
*/
public class Utils {
private static final String XMLNAMESPACE = "xmlns";
/**
* Set a namespace/prefix on an element if it is not set already. First off, it searches for the element
* for the prefix associated with the specified namespace. If the prefix isn't null, then this is
* returned. Otherwise, it creates a new attribute using the namespace/prefix passed as parameters.
*
* @param element
* @param namespace
* @param prefix
* @return the prefix associated with the set namespace
*/
public static String setNamespace(Element element, String namespace, String prefix) {
String pre = getPrefixRecursive(element, namespace);
if (pre != null) {
return pre;
}
element.setAttributeNS(XMLConstants.XMLNS_ATTRIBUTE_NS_URI, "xmlns:" + prefix, namespace);
return prefix;
}
public static String getPrefixRecursive(Element el, String ns) {
String prefix = getPrefix(el, ns);
if (prefix == null && el.getParentNode() instanceof Element) {
prefix = getPrefixRecursive((Element)el.getParentNode(), ns);
}
return prefix;
}
public static String getPrefix(Element el, String ns) {
NamedNodeMap atts = el.getAttributes();
for (int i = 0; i < atts.getLength(); i++) {
Node node = atts.item(i);
String name = node.getNodeName();
if (ns.equals(node.getNodeValue())
&& (name != null && (XMLNAMESPACE.equals(name) || name.startsWith(XMLNAMESPACE + ":")))) {
return node.getPrefix();
}
}
return null;
}
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