package de.timroes.axmlrpc;
import de.timroes.axmlrpc.xmlcreator.XmlElement;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* This class provides some utility methods for the use with the Java DOM parser.
*
* @author Tim Roes
*/
public class XMLUtil {
/**
* Returns the only child element in a given NodeList.
* Will throw an error if there is more then one child element or any other
* child that is not an element or an empty text string (whitespace are normal).
*
* @param list A NodeList of children nodes.
* @return The only child element in the given node list.
* @throws XMLRPCException Will be thrown if there is more then one child element
* except empty text nodes.
*/
public static Element getOnlyChildElement(NodeList list) throws XMLRPCException {
Element e = null;
Node n;
for(int i = 0; i < list.getLength(); i++) {
n = list.item(i);
// Strip only whitespace text elements and comments
if((n.getNodeType() == Node.TEXT_NODE
&& n.getNodeValue().trim().length() <= 0)
|| n.getNodeType() == Node.COMMENT_NODE)
continue;
// Check if there is anything else than an element node.
if(n.getNodeType() != Node.ELEMENT_NODE) {
throw new XMLRPCException("Only element nodes allowed.");
}
// If there was already an element, throw exception.
if(e != null) {
throw new XMLRPCException("Element has more than one children.");
}
e = (Element)n;
}
return e;
}
/**
* Returns the text node from a given NodeList. If the list contains
* more then just text nodes, an exception will be thrown.
*
* @param list The given list of nodes.
* @return The text of the given node list.
* @throws XMLRPCException Will be thrown if there is more than just one
* text node within the list.
*/
public static String getOnlyTextContent(NodeList list) throws XMLRPCException {
StringBuilder builder = new StringBuilder();
Node n;
for(int i = 0; i < list.getLength(); i++) {
n = list.item(i);
// Skip comments inside text tag.
if(n.getNodeType() == Node.COMMENT_NODE) {
continue;
}
if(n.getNodeType() != Node.TEXT_NODE) {
throw new XMLRPCException("Element must contain only text elements.");
}
builder.append(n.getNodeValue());
}
return builder.toString();
}
/**
* Checks if the given {@link NodeList} contains a child element.
*
* @param list The {@link NodeList} to check.
* @return Whether the {@link NodeList} contains children.
*/
public static boolean hasChildElement(NodeList list) {
Node n;
for(int i = 0; i < list.getLength(); i++) {
n = list.item(i);
if(n.getNodeType() == Node.ELEMENT_NODE) {
return true;
}
}
return false;
}
/**
* Creates an xml tag with a given type and content.
*
* @param type The type of the xml tag. What will be filled in the <..>.
* @param content The content of the tag.
* @return The xml tag with its content as a string.
*/
public static XmlElement makeXmlTag(String type, String content) {
XmlElement xml = new XmlElement(type);
xml.setContent(content);
return xml;
}
}